98 results
Search Results
2. Stakeholders' involvement and reflections on preserving sacred swamps in the Western Ghats, India, as revealed by participatory visioning.
- Author
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Hegde, Narasimha, Joosten, Hans, and Ziegler, Rafael
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NATURE conservation ,SWAMPS ,VALUE creation - Abstract
Lack of a shared vision has been identified as a major obstacle in transdisciplinary research involving both scientists and other stakeholders. Without a shared vision, the implementation of scientific findings is difficult. The diverse partners of collaborative research, however, imply a plurality in the valuation of nature and a need for deliberative mechanisms. If visioning processes are to do justice to local contexts, research must apply deliberative mechanisms to cover the plurality in the valuation of nature. This paper proposes a visioning approach for local communities, based on prior transdisciplinary research. This participatory workshop method invites stakeholders to approach nature conservation and livelihoods via a deliberation of desirable futures, barriers for achieving them and associated responsibilities for taking action. The paper explores this method via a case study of visioning workshops on sacred swamps in the Western Ghats (India), and their role for both freshwater swamp protection and livelihoods. The visioning exercise offered discussion opportunities facilitating conscientization, conciliation and collaboration in local bottom-up nature conservation. For conserving the tropical freshwater swamps, the results show the need for a more participatory forest governance, providing space for shared value creation. They also point to the need for further research on inter-faith nature conservation possibilities, along with innovations on value addition and value chain development for livelihood promotion and protection. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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3. Hypoglycemic and hepatoprotective activity of Phellinus fastuosus on streptozotocin-induced diabetic rats and carbon tetrachloride-intoxicated rats, respectively.
- Author
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Sonawane, Hiralal, Shelke, Deepak, Arya, Sagar, Ghole, Vikram, Behra, Bhaskar, and Gaikwad, Subhash
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STREPTOZOTOCIN ,PHELLINUS ,RATS ,ERYTHROCYTE membranes ,WEIGHT gain - Abstract
Background: Phellinus fastuosus is a wood-eating medicinal fungus from Western Ghats of India. Therefore, we investigated hypoglycemic and hepatoprotective effects of P. fastuosus aqueous extract on streptozotocin-induced diabetic and carbon tetrachloride (CCl
4 ) induced hepatotoxicity in rats, respectively. Result: As compared to the diabetic control group, a 400 mg/kg dose had significant hypoglycemic effects, including a reduction in blood glucose (24.44%) and gain in body weight. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity reduced by 31.81% and 32.84%, respectively, were also noted, along with decreases in triglycerides (24.32%) and cholesterol (25.89%) levels. The albumin, bilirubin and creatinine levels were also significantly reduced after administration of P. fastuosus extract in diabetic rats. Administration of P. fastuosus extract showed a substantial decrease in the activity of ALT, AST, alkaline phosphatase (ALP), catalase (CAT) and superoxide dismutase (SOD) in addition a decrease in the level of lipid peroxidation (LPO) as compared to CCl4 -intoxicated rats. The cumulative effect of CCl4 increased the erythrocyte membrane peroxidation, whereas P. fastuosus extract reduced the cholesterol and increased phospholipid, thus preventing the alteration of membrane fluidity as compared to CCl4 -intoxicated rats. FTIR and HR-LC-MS-based metabolic profiling revealed the presence of various functional groups and bioactive metabolites. Conclusion: The extract showed the hypoglycemic and hepatoprotective effects due to the presence of various bioactive metabolites. Exploration of therapeutic potential of P. fastuosus using bioassay-guided fractionation is needed. [ABSTRACT FROM AUTHOR]- Published
- 2024
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4. On-farm crop diversity, conservation, importance and value: a case study of landraces from Western Ghats of Karnataka, India.
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Puneeth, G. M., Gowthami, Ravi, Katral, Ashvinkumar, Laxmisha, Kerekoppa Manjunatha, Vasudeva, Ramesh, Singh, Gyanendra Pratap, and Archak, Sunil
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TROPICAL crops ,TUBER crops ,CULTIVARS ,GERMPLASM ,CROPS ,TRADITIONAL farming - Abstract
Landraces are important genetic resources that have a significant role in maintaining the long-term sustainability of traditional agro-ecosystems, food, nutrition, and livelihood security. In an effort to document landraces in the on-farm conservation context, Central Western Ghat region in India was surveyed. A total of 671 landraces belonging to 60 crops were recorded from 24 sites. The custodian farmers were found to conserve a variety of crops including vegetables, cereals and pulses, perennial fruits, spices, tuber and plantation crops. The survey indicated a difference in the prevalence of landraces across the sites. A significant difference with respect to the Shannon-diversity index, Gini-Simpson index, evenness, species richness, and abundance was observed among the different survey sites. Computation of a prevalence index indicated the need for immediate intervention in the form of collecting and ex situ conservation of landraces of some crops as a back-up to on-farm conservation. The study also identified the critical determinants of on-farm conservation, including (i) suitability to regional conditions, (ii) relevance in regional cuisine and local medicinal practices, (iii) cultural and traditional significance, and (iv) economic advantage. The information documented in this study is expected to promote the collection and conservation of landraces ex situ. The National Genebank housed at ICAR-NBPGR, New Delhi conserves around 550 accessions of landraces collected from the Central Western Ghats region surveyed in this report. Information collected from custodian farmers on specific uses will be helpful to enhance the utilization of these accessions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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5. How Long a Tropical Mountainous Lake Can Survive? Inferences from Geochemistry and Radiometric Measurements of Pookode Lake, Kerala, India.
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Gopinath, Girish, Resmi, T. R., Karunakara, N., Manjula, P., Jesiya, N. P., Sudeep Kumara, K., and Srinivas, Reji
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LAKES ,HEAVY metals ,GEOCHEMISTRY ,SEDIMENTATION & deposition - Abstract
Pookode, the freshwater lake in the Western Ghats, is a well-known tourist place in southern India, and human interference has turned the otherwise serene environment into a polluted one. This paper discusses the geochemical and textural characteristics of the Pookode lake and by determining the sedimentation rate, an attempt is made to predict the useful life of the lake. The predominance of mud fraction and high organic matter content in sediments favour the accumulation of heavy metals as indicated by the different indices. The sedimentation rate was determined using
137 Cs dating method and the maximum lifespan of the lake maintaining its hydrological and ecological functions is estimated as ∼700 years. [ABSTRACT FROM AUTHOR]- Published
- 2023
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6. Do river basins shape genetic structure in the Kempholey night frog, India?
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Priti, Hebbar, Anisha, Anand, Pavankumar, Thunga, Gururaja, Kotambylu Vasudeva, Aravind, Neelavar Anantharam, and Ravikanth, Gudasalamani
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FROGS ,AMPHIBIAN diversity ,GENETIC variation ,WILDLIFE conservation ,POPULATION genetics - Abstract
Amphibians are one of the most threatened groups of vertebrates globally. For effective conservation, understanding the patterns and processes underlying amphibian diversity is essential. Studies of genetic diversity and structure among conspecific populations and closely related species can provide crucial insights for their conservation; however, such studies are limited in South Asian tropical areas with high anuran diversity. In this study, we investigated the genetic diversity and structure in a widespread endemic frog, Nyctibatrachus kempholeyensis from the Western Ghats, India. Both mitochondrial and nuclear markers were used to analyse the phylogeographical and population genetic structure at multiple geographic scales. At a broader scale, river basins appeared to be weak barriers and genetic variation was more influenced by geographic distance. At a regional scale, headwater specialization and poor dispersal capability of N. kempholeyensis influenced the apportionment of genetic variation. The conservation planning for this species should consider the increased divergence of peripheral populations as well as develop measures at the stream scale to improve the gene-flow among the populations. This is the first population genetics study on freshwater amphibians from the Western Ghats, India and the results of our study will provide important baseline data for the conservation and management of freshwater dependent amphibians from this region. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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7. Individual and Combined Impacts of Land Use/Cover and Climate Change on Water Balance Components of a Tropical River Basin.
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Sharma, Swatantra Kumar, Sinha, Rakesh Kumar, Eldho, T. I., and Patel, H. M.
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WATER management ,CLIMATE change ,LAND use ,GENERAL circulation model ,LAND cover ,YIELD surfaces ,WATERSHEDS - Abstract
The land use/land cover (LULC) and climate change have detrimental impacts on the water balancing component (WBC) of a river basin, especially in the humid tropical regions. The aim of this study is to assess changes in the past, present, and future WBCs by analyzing the individual and combined impacts of both climate as well as LULC changes using the soil and water assessment tool (SWAT) model for a humid tropical Pamba river basin (PRB) in Western Ghats, India. To investigate the near (2021–2040), mid (2041–2070), and far (2071–2099) future effects of changing climate and LULC on WBCs, an ensemble of five general circulation models (GCM) with representative concentration pathways (RCPs) 4.5 and 8.5 scenarios was considered. Future LULCs for 2030, 2050, 2075, and 2100 were prepared using the Land Change Modeler (LCM) considering the normal LULC growth. The results show that the effects of LULC change increase the water yield and surface runoff while decreasing evapotranspiration (ET) throughout the study period (1988 to 2100). The climate change impacts show ET, water yield, and surface runoff decreases in the future for both RCP scenarios (except water yield, which increases only in near future for both RCPs). The trend of combined impacts on ET, water yield, and surface runoff for the future time was similar to the climate change trend. The results indicate climate change is dominant on WBCs in the future in the PRB due to variation in precipitation and temperature under both RCP 4.5 and 8.5 emission scenarios. This study will be useful for the overall water resources management of the river basin considered and the methodological framework can be adapted for other similar river basins. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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8. Detection of groundwater potential zones using analytical hierarchical process (AHP) for a tropical river basin in the Western Ghats of India.
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Das, Soumik, Mukherjee, Jayesh, Bhattacharyya, Suman, Patel, Priyank Pravin, and Banerjee, Anushna
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WATERSHEDS ,LAND cover ,GROUNDWATER ,RECEIVER operating characteristic curves ,SOIL classification ,RAINFALL - Abstract
This paper delineates the groundwater potential zones (GWPZ) within the Tadri River Basin in the Western Ghats of India, using analytical hierarchical process (AHP) and geoinformatics-based techniques. Eight discrete parameters (slope, rainfall, drainage density, lineament density, lithological units, geomorphological units, soil types and land use, and land cover classes) were selected and weighted according to their influence on groundwater availability and combined in a hierarchical manner to obtain the resulting GWPZ map. This was classified into five classes (very good, good, moderate, low and very low) depending upon the relative groundwater availability within each. Excellent GWPZ were present in the lower part of the Tadri Basin and along the Western Ghats' foothills beside the coast while the pediment-pediplain complex had less viability. The GWPZ map was validated using the area's average groundwater depth and well density, via the receiver operating characteristic (ROC) curve and the area under curve (AUC), which elicited an accuracy of 79% and 82.1%, respectively. Sensitivity analysis revealed that the basin's lithology, land use/land cover, drainage density and lineament density had the most impact in GWPZ delineation. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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9. Warming inhibits increases in vegetation net primary productivity despite greening in India.
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Das, Ripan, Chaturvedi, Rajiv Kumar, Roy, Adrija, Karmakar, Subhankar, and Ghosh, Subimal
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LEAF area index ,PRIMARY productivity (Biology) ,FOREST management ,FOREST microclimatology ,VEGETATION dynamics - Abstract
India is the second-highest contributor to the post-2000 global greening. However, with satellite data, here we show that this 18.51% increase in Leaf Area Index (LAI) during 2001–2019 fails to translate into increased carbon uptake due to warming constraints. Our analysis further shows 6.19% decrease in Net Primary Productivity (NPP) during 2001–2019 over the temporally consistent forests in India despite 6.75% increase in LAI. We identify hotspots of statistically significant decreasing trends in NPP over the key forested regions of Northeast India, Peninsular India, and the Western Ghats. Together, these areas contribute to more than 31% of the NPP of India (1274.8 TgC.year
−1 ). These three regions are also the warming hotspots in India. Granger Causality analysis confirms that temperature causes the changes in net-photosynthesis of vegetation. Decreasing photosynthesis and stable respiration, above a threshold temperature, over these regions, as seen in observations, are the key reasons behind the declining NPP. Our analysis shows that warming has already started affecting carbon uptake in Indian forests and calls for improved climate resilient forest management practices in a warming world. [ABSTRACT FROM AUTHOR]- Published
- 2023
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10. Role of south-west Indian orography in modulating large-scale monsoon circulation.
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Das, Renu S., Rao, Suryachandra A., Pillai, Prasanth A., Pradhan, Maheswar, and Srivastava, Ankur
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TROPICAL cyclones ,STANDING waves ,ROSSBY waves ,MONSOONS ,RAINFALL ,GENERAL circulation model ,SUMMER - Abstract
During the summer monsoon season, the Indian region experiences prominent south-westerly winds that extend up to the Philippines. These south-westerly winds encounter the Western Ghats (WG) and Deccan Plateau (DP). Many studies have discussed the role of WG in modulating the monsoon flow, convection and rainfall over the Indian region. However, the orographic influence of south-west orography (DP and WG both) on large-scale monsoon circulation remains unexplored. An experimental global model simulation was conducted with removed DP and WG orography to investigate this. The results showed that modifying the orography can alter the wind flow across the Philippines, Western North Pacific, and Bay of Bengal, leading to mid-tropospheric heating changes due to the monsoon trough position over these regions. This change in the monsoon trough position results in the stationary Rossby wave. The stationary Rossby wave generated strengthened winds over the south Bay of Bengal (BoB), which merges with the Philippine anticyclone over the Western North Pacific. The dynamical and thermodynamical changes are observed near Western North Pacific. Consequently, there is an increase in rainfall over the Western North Pacific and a decrease in rainfall over India. This study also found that the change in the monsoon flow affects the low-pressure systems and tropical cyclones. This work highlights how the South-West Indian orography affects the monsoon flow and synoptic variability across India, the West North Pacific, and the Philippines anticyclone. Thus, understanding the monsoon flow over the orography will help understand the dynamics. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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11. A new species of termite, Prorhinotermes cotym (Blattodea: Isoptera: Rhinotermitidae: Prorhinotermitinae), from the Kerala part of the western ghats, India.
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Joseph, Edwin, Amina, Poovoli, Thomas B S, Sarath, Jayan, Namitha, and Mathew, Jobin
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CYTOCHROME oxidase ,SPECIES distribution ,SPECIES ,CASTE - Abstract
Genus Prorhinotermes Silvestri (Isoptera: Rhinotermitidae) is very rare in India, known by single species Prorhinotermes flavus. After three decades, a new species Prorhinotermes cotym Joseph, Amina and Mathew sp.nov, is described from the Kerala part of the Western Ghats, India. The genus Prorhinotermes is documented for the first time from Kerala. Morphological measurements of the soldiers and workers are given with suitable illustrations. Cytochrome oxidase II gene subunit was sequenced based on which phylogenetic analysis was carried out. A revised key to the species of Prorhinotermes (based on soldier caste) found in India with the species distribution map is provided. [ABSTRACT FROM AUTHOR]
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- 2023
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12. Effects of land use and climate change on water scarcity in rivers of the Western Ghats of India.
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Sharannya, T. M., Venkatesh, K., Mudbhatkal, Amogh, Dineshkumar, M., and Mahesha, Amai
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WATER shortages ,CLIMATE change ,LAND use ,GENERAL circulation model ,WATERSHEDS - Abstract
This paper assesses the long-term combined effects of land use (LU) and climate change on river hydrology and water scarcity of two rivers of the Western Ghats of India. The historical LU changes were studied for four decades (1988–2016) using the maximum likelihood algorithm and the long-term LU (2016–2075) was estimated using the Dyna-CLUE prediction model. Five General Circulation Models (GCMs) were utilized to assess the effects of climate change (CC) and the Soil and Water Assessment Tool (SWAT) model was used for hydrological modeling of the two river catchments. To characterize granular effects of LU and CC on regional hydrology, a scenario approach was adopted and three scenarios depicting near-future (2006–2040), mid-future (2041–2070), and far-future (2071–2100) based on climate were established. The present rate of LU change indicated a reduction in forest cover by 20% and an increase in urbanized areas by 9.5% between 1988 and 2016. It was estimated that forest cover in the catchments may be expected to halve compared to the present-day LU (55% in 2016 to 23% in 2075), along with large-scale conversion to agricultural lands (13.5% in 2016 to 49.5% in 2075). As a result of changes to LU and forecasted climate, it was found that rivers in the Western Ghats of India might face scarcity of fresh water in the next two decades until the year 2040. However, because of large-scale LU conversion toward the year 2050, streamflow in rivers might increase as high as 70.94% at certain times of the year. Although an increase in streamflow is perceived favorable, the streamflow changes during summer and winter may be expected to affect the cropping calendar and crop yield. The changes to streamflow were also linked to a 4.2% increase in ecologically sensitive wetlands of the Aghanashini river catchment. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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13. Engineering geological investigation and runout modelling of the disastrous Taliye landslide, Maharashtra, India of 22 July 2021.
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Peethambaran, Bipin, Nandakumar, V., and Sweta, Kumari
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LANDSLIDES ,DEBRIS avalanches ,LANDSLIDE hazard analysis ,FLOW velocity ,PADDY fields - Abstract
The Taliye landslide, a hill slope debris flow, is one of the recent large-scale landslides in India in terms of mortality and socio-economic predicaments. In general, the Taliye area exhibits a moderately dissected plateau relief, and the landslide was initiated from a north-westerly slope of a west trending major ridge and flowed through a paddy field to bury houses located just below it. The landslide had a total runout of 563 m and maximum width of 230 m at the toe. The heavy rainfall and presence of a narrow stream may be the prime triggering factors, but the affected area had also been exposed to human interference for farming as well as for habitation. Given its socio-economic relevance and landslide proneness of this area, a post-event engineering geological investigation and numerical modelling of this landslide have been carried out to have a closer look at its type, causes of failure, back calculation of run-out characteristics, as well as to calibrate frictional parameters for this area. The numerical modelling package, rapid mass movements (RAMMS) was used to undertake back analysis of this debris flow by referring the original flow shape. For the precise preference of Voellmy frictional parameters, dry-Coulomb friction (µ) and viscous-turbulent friction (ξ) coefficients, this study applies the popular receiver operative characteristics (ROC) technique as the model validation tool. The landslide may have initiated as a talus or translational failure of shallow soil on the hillock, but later might have transformed into a debris flow by entraining materials from the paddy field. Amongst the different combinations of frictional parameters, the model with µ of 0.06 m/s
2 and ξ of 1450 m/s2 has emerged as the best with an area under the curve (AUC) value of 0.883 for the ROC assessment. With these calibrated frictional parameters, the maximum flow velocity of this debris flow was simulated to be in the order of 5.26 m/s taking place at the middle reaches, and the maximum flow velocity and pressure were derived as 21 m/s and 0.92 kPa, respectively, concentrated in the hillock zone. Although it was a rain-induced failure, the investigation suggests that improper slope management practices might have amplified its magnitude and got manifested as devastating landslide. Therefore, human activities in these hilly regions shall be supported with systematic landslide hazard evaluation, and here in this case, the calibrated frictional parameters may be useful for debris flow modelling and landslide risk reduction in the area. [ABSTRACT FROM AUTHOR]- Published
- 2023
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14. Spatio-temporal analysis of rainfall pattern in the Western Ghats region of India.
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Venkatesh, B., Nayak, P. C., Thomas, T., Jain, Sharad K., and Tyagi, J. V.
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WATER supply ,TARDIGRADA ,MONSOONS ,HOMOGENEITY - Abstract
This paper investigates the rainfall pattern and its distribution, which is one of the key drivers for the water availability in the Western Ghats region of India. The daily precipitation data from 1901 to 2014 were investigated to understand the rainfall pattern and its variability. The study area has been divided as southern, coastal, central, and northern regions and rainfall amount into 0.2–10 mm, 10–20 mm, and > 50 mm classes. The trends in the annual rainfall, number of rainy days, and various classes within these regions have been investigated. The mean annual rainfall varies between 4000 mm in the coastal areas and greater than 6000 mm at the mountain crest. The Mann–Kendall test indicates significant decrease of annual rainfall, at 5% significance level in central and coastal region. On Contrary, the coastal region recorded significant decrease in the number of rainy days at 5% significance level. An increasing trend in the number of rainy days has been observed in the northern region. No significant trends have been detected in the southern region. A decreasing trend has been detected in the number of rainy days in the rainfall class with 10–20 mm in coastal region. Similarly a significant decrease of rainy days was observed in > 50 mm rainfall class both in the southern and northern regions. The change point probability and homogeneity test indicates that there is a significant increase in rainfall in few stations under the northern region and similarly decrease in the rainfall in central region during the decade of 1970 and normally the rainfall has been homogeneous in the study area. From the precipitation concentration analysis found that Mysore, Kodagu, and adjoining areas are influenced by the bi-modal rainfall, receiving the rainfall during both south–west and north–east monsoons. This analysis helps to understand the spatial variability of rainfall in the Western Ghats of India, which depict mixed trends in the quantum of rainfall and decreasing trend of rainy days across various rainfall classes. These changes detected in the historical rainfall, both in its occurrence and quantum will have significant bearing on the water availability scenario in the Western Ghats region. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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15. Impact of physical processes on oxygen loss and production of hydrogen sulphide and methane in a tropical freshwater reservoir.
- Author
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Shenoy, Damodar M., Kurian, Siby, Shirodkar, Gayatri, Uskaikar, Hema, Gauns, Mangesh, and Naqvi, Syed Wajih Ahmed
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HYDROGEN sulfide ,HYDROGEN production ,METHANE ,FRESH water ,GLOBAL warming - Abstract
Carbon neutrality of tropical reservoirs is a big concern in recent years as some estimates project high methane emission from these reservoirs. While there are studies available on the impact of physical processes (stratification and mixing) on the biogeochemistry of tropical reservoirs, not much information is available on the inter-annual variability in the low-oxygen conditions and production/accumulation of hydrogen sulphide (H
2 S) and methane (CH4 ) during summer. This paper presents time series data based on monthly in situ observations from a tropical reservoir (Tillari, Maharashtra) situated in the Western Ghats in India. Sampling was carried out for temperature, dissolved oxygen (DO), H2 S, and CH4 at a fixed location from March 2010 until June 2014. The reservoir experiences stable stratification during summer (March to June) with complete loss of oxygen and production of H2 S (max. ~ 9 μM) and CH4 (max. ~ 185 μM) in the profundal zone. During the summer stratification, the hypolimnion acted as a pool of CH4 with integrated values ranging between 3502 and 41,632 mg m−2 . However, the intensity and duration of anoxia varied during different years, influencing H2 S and CH4 production. Mixing in the reservoir was observed between July and September in association with the monsoonal runoff, which increased the DO concentrations in the sub-surface layers. Besides, complete mixing was observed between December and February due to winter convection. This, however, was found to play an important role, as weaker mixing in the preceding year was associated with severe oxygen loss in the profundal zone during the following summer with a production of H2 S and CH4 . In contrast, more robust mixing during winter led to moderate low-oxygen conditions with less production of these gases in the subsequent summer. Based on our observations and considering a large number of reservoirs in the tropics, we hypothesise that with the present trends of global warming and less cold winters, low-oxygen conditions in the profundal zone may become more severe in the future with positive feedback on H2 S and CH4 production during summer. [ABSTRACT FROM AUTHOR]- Published
- 2021
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16. Geospatial landslide inventory of India—an insight into occurrence and exposure on a national scale.
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Martha, Tapas Ranjan, Roy, Priyom, Jain, Nirmala, Khanna, Kirti, Mrinalni, K., Kumar, K. Vinod, and Rao, P. V. N.
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LANDSLIDE hazard analysis ,LANDSLIDES ,HAZARD mitigation ,METAMORPHIC rocks ,REMOTE sensing ,INVENTORIES ,POPULATION density - Abstract
India ranks first in the world in terms of fatal landslides. Large vulnerable area (0.42 million km
2 ), high population density and monsoon rainfall make India's landslide management and mitigation task difficult. Therefore, an understanding of landslide occurrences and exposure of socio-economic parameters on a national scale is essential to prioritise landslide mitigation efforts. In this paper, a database of 45,334 landslides (polygons) in India mapped by the National Remote Sensing Centre (NRSC) during the 1998–2018 period was compiled and catalogued in a WebGIS platform. High-resolution satellite data such as IRS PAN+LISS-III, Resourcesat LISS-IV Mx, Cartosat, WorldView, Pleiades and GeoEye were used to map landslides as small as 12 m2 to as big as 1,390,350 m2 . GIS analysis using the landslide inventory revealed interesting results about control, exposure and pattern of landslide occurrences in India. The Northwest Himalayas contribute 66.5% of landslides in India, followed by the Northeast Himalayas (18.8%) and the Western Ghats (14.7%). The Greater Himalayan sequence consisting of high-grade metamorphic rocks has a considerable control (32%), and the Main Central Thrust is the major regional structure controlling (12%) landslides in India. In the Northeast Himalayas, the size of landslides and the slope gradient controlling landslide occurrence are less in comparison to the Northwest Himalayas and the Western Ghats. Landslides in the Western Ghats are triggered with a lesser amount of rainfall than the Himalayan regions. Exposure analysis using four key socio-economic parameters in the 145 hilly districts shows that Rudraprayag district is most affected by landslides in India. The understanding derived using the landslide database on a national scale will help to prioritise and strengthen landslide disaster risk reduction strategies in India. [ABSTRACT FROM AUTHOR]- Published
- 2021
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17. Timmiella goaense gen. n., sp. n. (Nematoda: Dorylaimida: Belondiroidea) from Western Ghats of India.
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Kumar, Sumit and Ahmad, Wasim
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GENITALIA ,FUSIFORM gyrus ,NEMATODES ,PHARYNX ,VULVA ,INTESTINES - Abstract
Timmiella goaense gen. n., sp. n. closely related to genera Swangeria Thorne, 1939, Qudsiella Jairajpuri, 1967 and Timmus Goseco, Ferris and Ferris, 1976 is described and illustrated based on specimens collected from Western Ghats of India. The new genus is characterized by its broadly rounded, continuous lip region; odontostyle short, delicate with indistinct lumen and aperture; guiding ring thick belt-like, conspicuous; anterior part of pharynx slender, a narrow tube; expanded part of pharynx fusiform, enclosed by sinistrally spiral muscular sheath; cardia isthmus-like (spatulate) with intestine attached to its posterior end; female genital system amphidelphic; vulva transverse; male with dorylaimoid spicules; tail long filiform, similar in both sexes. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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18. Diagnosing whether the increasing horizontal resolution of regional climate model inevitably capable of adding value: investigation for Indian summer monsoon.
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Mishra, Alok Kumar, Dubey, Aditya Kumar, and Dinesh, Anand Singh
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ATMOSPHERIC models ,PROBABILITY density function ,DOWNSCALING (Climatology) ,RAINFALL ,CLIMATOLOGY - Abstract
This study demonstrated the influence of downscaling using the regional climate model (RCM) driven by Era-Interim reanalysis (EIN) in simulating different aspects of the Indian summer monsoon (ISM). It is also examined, whether increasing the horizontal resolution of RCM will inevitably be capable of adding more information to ISM characteristics and its spatio-temporal variability. In this regard, two RCM (at 50 km: Reg
50 and 25 km: Reg25 ) simulations were conducted for six years from 2000 to 2005 for the South Asia Coordinated Regional Downscaling Experiment (CORDEX) domain. The added value (AV) is found to be strongly dependent on region and considered metrics. A slight improvement towards increasing spatial resolution is observed in the simulation of the mean ISM characteristics, while considerable improvements are noticed for the frequency distribution of extremes. The notable improvement in the daily climatology of precipitation is observed over the region of northeast India (~ 35%) and the Hilly region (~ 32%) and the lowest improvement over north-central India (~ 8%). The reduction of anomalously strong northeasterly flow over the southeastern Arabian Sea and strengthening of the moisture leaden southeasterly wind flow from the Bay of Bengal in Reg25 compared to Reg50 is consistent with the reduction of dry bias over India in Reg25 . The robust improvements are noticed for the heavy precipitation events (probability density function: PDF tails) and mean precipitation due to extreme precipitation events, particularly over the areas characterized by complex topographical features (e.g., the Western Ghats, Indo-Gangetic plains, and northeast India and Hilly regions) as well as over the areas having substantial bias (e.g., central India), indicating its strong sensitivity towards model resolution. The increasing latent heat flux in Reg25 contributes to increasing the moisture and hence rainfall over India. Both simulations apparently simulate many of the ISM characteristics better than the EIN, thereby emphasizing the usefulness of finer resolutions in the better simulation of the Indian monsoon, especially for heavy rainfall. However, the RegCM bias is comparable to or even greater in some places than the EIN bias. This suggests that high-resolution models are important for improving performance; however, it does not necessarily mean that they can have AV for every aspect and all places. Apart from this, the substantial difference in the AV over different regions or aspects highlights the importance of carefully selecting AV matrices for the different areas and characteristics being investigated. RegCM exhibits some systematic biases in precipitation despite substantial improvement due to misrepresentation of dynamical and thermodynamical processes, including northward and eastward propagating convective bands. [ABSTRACT FROM AUTHOR]- Published
- 2023
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19. Analysis of anticancer potential of Kingiodendron pinnatum (DC.) Harms.
- Author
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Pareeth, Chennattu M., Meera, Nair, Silpa, Prabha, Thara, Kannoor M., Raghavamenon, Achuthan C., and Babu, Thekkekara D.
- Subjects
EHRLICH ascites carcinoma ,ORAL drug administration ,GENITALIA ,CELL lines ,PLANT extracts - Abstract
Background: The plant Kingiodendron pinnatum (DC.) Harms, belonging to the family Fabaceae is endemic to the Western Ghats of India and is commonly used for various ailments, especially by the tribes. K. pinnatum is occasionally used as a substitute for Saraca asoca in Asokarishta, a well-known uterine tonic in Ayurveda. Recent studies revealed a pharmacological similarity between the plants. S. asoca is reported to have anti-cancer properties, but there are no reports on K. pinnatum except for antioxidant and antimicrobial activities. Therefore, the study is aimed to investigate the anticancer potential of the plant. Methods: Cytotoxicity of methanolic bark extract of the plant was analysed on different cancer cell lines by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Dalton's lymphoma ascites (DLA) cell-induced solid and Ehrlich ascites carcinoma (EAC) cell-induced ascites tumour models in mice were used to study the antitumor potential. Phytochemical screening of the extract was also performed. Results: The extract was found cytotoxic to DLA, EAC, HCT15, MDA-MB-231, T47D and PC3 with inhibitory concentration (IC
50 ) values of 50.09, 74.74, 67.02, 119.22, 149.04 and 194.5 μg/mL, respectively. In the solid tumour model, a significant (P < 0.001) reduction in tumour weight of 0.7 ± 0.15 g was observed in 500 mg/kg b.wt. extract treated group compared to the control group (3.6 ± 0.24 g) by oral administration for 30 days. In the ascites tumour model, a high survival rate of 28.2 ± 8.72 days (P < 0.01) was found by the extract treatment compared to the control animals. Phytochemicals like alkaloids, flavonoids, phenols, phytosterols, saponins, tannins, steroids and terpenoids were detected in the extract. Conclusion: Results obtained by the cytotoxic and anti-tumour studies revealed the anticancer potential of K. pinnatum. The plant exhibits more cytotoxicity towards cancer cell lines of the reproductive system such as the breast and prostate. [ABSTRACT FROM AUTHOR]- Published
- 2023
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- View/download PDF
20. Evaluation of landslide hazard and its impacts on hilly environment of the Nilgiris District - a geospatial approach.
- Author
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Thennavan, Edison and Pattukandan Ganapathy, Ganapathy
- Subjects
LANDSLIDES ,LANDSLIDE hazard analysis ,GOVERNMENT agencies - Abstract
Landslide Hazard Zonation (LSH) maps play a key role in landuse planning particularly in landslide prone areas. LSH mapping is globally accepted one for analyzing the area for landslide susceptibility. Different approaches were followed by many researchers in India to prepare landslide hazard zonation mapping depending upon their need and requirement. The Nilgiris district in Western Ghats of India is one of the severe to high landslide hazard prone areas of India. Many agencies have carried out research on LSH mapping for the Nilgiris district with different scales. A systematic study of inventory and zonation was 122carried out in 1980's by government agencies. However there is no proper updation or documentation on landslides after 1980's in the district The purpose of this paper is to review the existing landslide-related studies in the district of The Nilgiris and review the district's existing landslide hazard map with updated information. Landslide hazard maps in The Nilgiris were compiled in the GIS platform from various authenticated sources. Data on landslides from 1824 to 2014 were collected and a spatial database on landslides was created. A detailed inventory was analyzed and used for revision of the district's landslide hazard impact on the 2009 landslides.. Based on the landslide inventory and densely populated areas and repeated landslides at the same locations, the most landslide hazard areas were identified. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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21. A Numerical Study on Extent of Crushed Zone Around Blasthole in Basalt Rock.
- Author
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Juneja, Ashish and Pinaki, Partha
- Subjects
BASALT ,SOIL vibration ,BLAST effect ,EARTHQUAKE zones ,ROCKS ,DAMAGE models ,ROCK deformation - Abstract
Proper understanding of the rock breakage mechanism is important in tunnelling and mining activities. The excavation design uses complex energy distribution pattern when explosion and rock-blast occurs. This paper investigates the effect of a controlled-blast in rock mass using a numerical technique. The rock material properties were determined and fitted in an advance material damage model using the finite element code LS-DYNA. This material model had three governing surfaces, each of which was dependent upon the plastic strain accumulation. The damage zones around the blast hole were categorised into crushed, seismic and elastic zones. In all the cases, the material within the close vicinity of the explosion, failed in compression, whilst the material at distance away from the explosion, failed in tension. The influence of loading rate and its impact on the fracture pattern was also studied. It was shown that the higher loading rate led to the formation of short cracks and areas with large crack densities whereas longer and definite cracks occurred when the loading rate was slow. In both the cases, the rise time was found to be more significant than the decay time. This lead to the development of a relation between the critical rise time corresponding to the maximum damage. Crack velocities were higher for quick loading rates and achieved one-half the magnitude of P-wave velocity observed on basalt rock. The results of this model were validated using the case study of a tunnel excavation in Western Ghats of Peninsular India The numerically obtained ground vibrations in the old tunnel were observed to be under the permissible limits. Likewise, the vibrations deduced in the new tunnels indicated the initiation of cracks. Notwithstanding the above, a reasonably good comparison was obtained between the measured and predicted peak particle velocities. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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22. A review of research and conservation of Myristica swamps, a threatened freshwater swamp of the Western Ghats, India.
- Author
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Ranganathan, Priya, Ravikanth, G., and Aravind, N. A.
- Subjects
SWAMPS ,FRESHWATER biodiversity ,ANIMAL diversity ,LITERATURE reviews ,FRESHWATER habitats ,ENDANGERED ecosystems ,FRESH water - Abstract
Myristica swamps are tree-covered wetlands within the evergreen forests of the Western Ghats, India. Even with their little-known biota, the swamps are virtually a live museum that is of great interest to biologists. The swamps harbour several rare-relic floristic and faunal taxa, comprising many endemic and threatened species. Most of the plant species in the swamp are highly restricted in their distribution and have several structural and physiological modifications. These swamps are one of the most unique and primeval ecosystems of the Western Ghats. They once formed a large hydrological network all along the Western Ghats, but due to increased human pressure, these now exist as small, isolated pockets and are one of the most threatened ecosystems in India. The presumed widespread loss of Myristica swamps and other perennial freshwater swamps calls for intensive research on the ecosystem services provided by these swamps, their landscape value and the function they play in watershed dynamics. Swamps are primarily drained for areca gardens and paddy fields. The swamps of the Western Ghats are threatened with extinction, yet scientists know little about them. Studies on flora and faunal diversity of these swamps exist, but the research gaps are notable when it comes to the hydrology, soil studies, and ecosystem services provided by these swamps. Further research is needed on these three topics in order to provide a comprehensive understanding of the abiotic factors governing swamps and to formulate a rationale for their preservation. There is also a lack of research on the potential impacts of climate change and population growth on these swamps. This review highlights the importance of these freshwater swamps, their ecology and prior research on them, and focuses on the need for conservation initiatives to save the last few swamps. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
23. Invasive nitrogen-fixing plants increase nitrogen availability and cycling rates in a montane tropical grassland.
- Author
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Raghurama, Manaswi and Sankaran, Mahesh
- Subjects
GRASSLAND soils ,INVASIVE plants ,NITROGEN cycle ,NITROGEN fixation ,BIOLOGICAL invasions ,GRASSLANDS ,BIOSPHERE reserves ,NUTRIENT cycles - Abstract
Invasive plants can impact nutrient cycling, potentially creating positive feedbacks for further invasion. We studied the impact of three woody nitrogen (N)-fixing invasive plant species on soil N-cycling and phosphatase activity in a montane tropical forest-grassland mosaic in the Nilgiri Biosphere Reserve in southern India, an ecosystem with > 100-year history of biological invasions. Soils were collected over a year from patches invaded by Acacia mearnsii, Cytisus scoparius, and Ulex europaeus, and from uninvaded grasslands, to assess inorganic N-availability and N-mineralization rates (using in situ open-top mineralization tubes). Phosphatase activity was measured from soils collected at the beginning of the growing season. Soils of invaded areas had higher inorganic N-availability and phosphatase activity than soils of uninvaded areas. Whilst net N-mineralization rates were unchanged between invaded and uninvaded sites, net nitrification rates were higher and net ammonification rates lower in invaded areas, particularly in the dry season. Impacts of C. scoparius and U. europaeus on these variables were similar to each other, and lower than the impacts of A. mearnsii. These results show that invasive N-fixers are significantly altering nutrient availability and cycling, and also changing the proportion of the forms of inorganic N available, in the Nilgiri grasslands. Restoration activities in these invaded grasslands should explore soil N management strategies such as soil C amendments and planting of specific native species, in conjunction with other strategies, to control invasive plants. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
24. Harvesting of water by tunnelling: A case study from lateritic terrains of Western Ghats, India.
- Author
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Joji, V S, Gayen, Anadi, and Saha, Dipankar
- Subjects
WATER tunnels ,WATER harvesting ,WATER seepage ,WATER-rock interaction ,LATERITE ,HORIZONTAL wells - Abstract
Harvesting of water by tunnelling in the Western Ghats lateritic terrains of India known as surangam (tunnel well) is practiced since ages. It is common even today in the northern parts of Kerala state in India. Surangams are featured by horizontal tunnel wells, dug manually within the laterite, where the tunnel wall collects the seepage water, flows out under gravity and get accumulated in open tanks or dug wells for further use. The tunnels are laid horizontally or slightly inclined, placed just over the lithomarge clay so that maximum seepage can be accumulated through the porous laterites (generally of 3.95–30.20 m thick). A study is done on surangams from the Kasaragod district of Kerala, where it is still popularly used. They represent different designs; single tunnel, criss-cross tunnels and diversion tunnels, depending upon the terrain conditions, the permeability of the laterites and thickness of the saturated zones within laterites, demand of water and location of delivery points, etc. Surangam system may start from a dug well, end in a dug well and there can be an open shaft or dug well in between. Total 32 surangams are inventoried in Bedadka Panchayath, of which 24 are investigated in detail. The discharge varies from 0.078 to 13.29 m
3 /day during pre-monsoon while it remains between 172.80 and 691.20 m3 /day during monsoon period in 2019. In 2019 summer, 12 inventoried surangams remained dry. The hydrochemical facies of water from the surangams generally varies from Ca–HCO3 type to Ca–Mg–Cl type indicating rock–water interaction. Because of lack of proper maintenance caving of walls occur during the rainy season. Lack of maintenance renders the priceless traditional groundwater abstraction structures disappearing fast. Surangams with good discharge are to be protected with proper concrete reinforcing of the outlet of the tunnel and proper storage options and arrangement of delivery systems up to the user point. Besides, water harvesting measures in the catchment of surangams are required for round the year sustainability of yield. A plan has been proposed for the revival of the surangams along with design specifications. [ABSTRACT FROM AUTHOR]- Published
- 2021
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- View/download PDF
25. New species of the genus Bionychiurus Pomorski, 1996 (Collembola: Onychiuridae) from India.
- Author
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Thunnisa, Abu Muhsina, Sumithra, Nallathambi, Narmatha, Senthilkumar, Jyothi, Manikkiri, and Sanil, Raveendranthanpillai
- Subjects
COLLEMBOLA ,CYTOCHROME oxidase ,SPECIES - Abstract
The genus Bionychiurus Pomorski, 1996 is not recorded from India so far. A new species nominated as Bionychiurus tamilensis sp. n. is described from the Nilgiri Hills in the Western Ghats. Bionychiurus tamilensis sp. n. possess a dorsal pso formula as 32/133/33,343 and a ventral pso formula as 11/011/11,121. The dorsal pso formula is similar to Bionychiurus changbaiensis, B. normalis, and B. oblongatus reported from China and Korea. The 658 bp mitochondrial cytochrome oxidase subunit I DNA region (COX1) of the new species was sequenced for its molecular identification. A modified key to genus Bionychiurus is provided. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
26. Agroforestry environment, potentiality and risk in India: a remote sensing and GIS understanding.
- Author
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Ahmad, Firoz, Uddin, Md Meraj, Goparaju, Laxmi, Talukdar, Nazimur Rahman, and Rizvi, Javed
- Subjects
AGROFORESTRY ,REMOTE sensing ,FARMS ,COASTAL plains ,RURAL planning - Abstract
The study utilized the tree covers per cent, agroforestry suitability, present and future (2050) climate, agriculture vulnerability (2050), percentage of people living Below Poverty Line (BPL) data sets and manoeuvered them in GIS platform to understand the agroforestry extent, potentiality and the critical multidimensional relationship among them. The total agroforestry area in India (if defined the tree cover per cent greater than 10% on agricultural land) was found to be 28 million hectares that is approximately 17% of the total agriculture land area which is remarkably less (global average 43%). The analysis further revealed that the agriculture land potential in India towards the agroforestry suitability category (S1: High suitability) is alone 75.6 million hectares that are 2.7 times of total existing agroforestry extent. Among all agro-ecological regions of India, the Eastern Plain agro-ecological region has high cropland potentiality which will help significantly in magnifying agroforestry set-up in the future. The analysis further revealed a very high poverty per cent (41–80%) category has approximately 5.3 million hectares of land under agroforestry, whereas the cropland potentiality (category S1) towards agroforestry was found approximately four times of the present agroforestry extent. The Western Ghats and the Coastal Plain agro-ecological region maintain a diversified agroforestry environment that will face double risk in the future (2050) due to precipitation deficit and also from significant temperature increase. Our analysis highlights the important agroforestry-related findings that will assist crucially to the decision-makers of India for implementing synergic strategies/planning of agroforestry at country/state/district/village levels. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
27. Role of Climate and Topography on Hydrological Characteristics of the Bharathapuzha Basin in the Tectonically Quiescent Western Ghats, India.
- Author
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Reddy, S. Kiran Kumar, Kotluri, Sravan Kumar, Gupta, Harish, and Reddy, D. Venkat
- Subjects
TOPOGRAPHY ,MATERIAL erosion ,CLIMATE change ,SEDIMENTS - Abstract
Intra-basin variations in sediment supply provide clues for understanding the erosion process and the role of local topographic features and climatic factors. Hence in this study, Bharathapuzha (BP) basin from tectonically quiescent Western Ghats (WG) was selected to examine the role of topography and climate on the sediment erosion process across its sub-basins. Multi-years daily water discharge and sediment load data of five monitoring stations were combined with morphometric parameters to visualize the local variability in sediment erosion rates. The average annual water discharge and sediment load of the BP basin to the Arabian Sea are 4.71 km
3 and 0.37×106 tons. Interestingly, Kunthipuzha (KP) sub-basin, despite covering 17% of the total basin area, contributes around 41% and 27% of water discharge and sediment flux, respectively. The sediment yield (erosion rate) from the KP sub-basin is ten times higher than the same sized sub-basin within the BP catchment. For comprehending the role of topography and climate on these local variations, geomorphic indices such as Hypsometric integral (HI) and stream length (SL) index were calculated for the BP basin and sub-basins. Further, multiple regression was used to explore the quantitative relationships among the influencing factors. Results suggest that the rainfall and topography critically influenced basin erosion and explained 93% of the total variance. This study demonstrates the importance of intra-basin scale processes even for small mountainous rivers and signifies the role of local variations in topography and climate in erosion and material transport. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
28. Spatiotemporal variability in groundwater chemistry of a mountainous catchment with complex geologic and climate gradients in south west India.
- Author
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Gayathri, J. A., Raj, Vipin T., Sreelash, K., Maya, K., Vandana, M., and Padmalal, D.
- Subjects
PALEOCLIMATOLOGY ,GROUNDWATER ,CHEMICAL weathering ,GROUNDWATER quality ,CARBONATE minerals - Abstract
Mountainous catchments are one of the world's important water sources that sustains a major portion of global population and a rich biodiversity. The groundwater quantity and quality of mountainous watersheds depend generally on the geologic characteristics and climate gradients. Although many groundwater studies have been carried out in the midlands and lowlands of many river basins, not enough focus has been paid to the mountainous catchments of tropical watersheds. Here we report a case study on groundwater quality and controlling factors of a mountainous catchments of the Western Ghats mountain ranges of peninsular India—the Bhavani river basin, which is identified as a testbed for long-term monitoring of the Critical Zone process. A total of 88 water samples were collected seasonally for assessing various physico-chemical parameters, solute contents and scaling properties. Standard methods were followed for the estimation of various hydrochemical parameters in the open and borewell samples. The results of the study revealed that higher pH and Total Dissolved Solids (TDS) are noticed in the talc-tremolite dominated central zone whereas low values are recorded in the charnockite dominated areas. The major cations in the water samples are of the order Ca
2+ > Mg2+ > Na+ > K+ and the anions are of the order HCO3 − > Cl− > SO4 2− . The content of Cl− shows higher values in areas close to agricultural/settlement areas. An overall evaluation shows that the hydrochemistry of groundwater in the study area is influenced by both silicate and carbonate weathering. Mineral stability indices computed for the groundwater reveal that about 52% of the samples are supersaturated with carbonate minerals and often exhibit scaling due to solute overloading. Saturation Index and mineral stability diagram also support that the incongruent dissolution of aluminosilicate minerals (silicate weathering) is an important hydrochemical process controlling the chemistry of groundwater. Langelier saturation index (LSI) and Puckorius scaling index (PSI) show that a significant number of open well and borewell samples exhibit scaling tendency. Among the contributing factors that determine water quality of groundwaters, chemical weathering and anthropogenic activities play a significant role. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
29. Prediction of dominant daily modes of the Indian summer monsoon in the NCEP GFS model.
- Author
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Shahi, Namendra Kumar, Rai, Shailendra, Sahai, A. K., and Abhilash, S.
- Subjects
PRECIPITATION anomalies ,MONSOONS ,SEASONS ,MADDEN-Julian oscillation ,SPECTRUM analysis ,FORECASTING - Abstract
The prediction capability of dominant daily monsoon modes of Indian summer monsoon in the forecast of the Global Forecast System Version 2 (GFSv2) model is scrutinized. The dominant monsoon modes are procured by performing the multichannel singular spectrum analysis (MSSA) on daily precipitation anomalies of the Indian summer monsoon region (60–100°E, Eq.-35°N) during 2001–2014. The observation has one seasonally persistent mode and two intraseasonal oscillations with periods around 42 and 26 days, and the model has correctly simulated these modes. The spatial structure of the phase composites of the precipitation anomalies of the intraseasonal modes of the model is almost similar to the observed spatial pattern with slightly less magnitude of the precipitation anomalies over Western India and the core monsoon zone. The spatial structure of the 26-day mode is similar to the spatial structure of the 42-day mode with less magnitude of the precipitation anomalies all over the study domain. The lead forecast of the model demonstrates the robust predictive skill of intraseasonal modes. The variation of the active and break spells of monsoon precipitation over the Indian subcontinent is captured accurately by the contribution of both intraseasonal modes. The observed eastward and northward propagation features of the Indian summer monsoon have been accurately simulated by the model. The model has weak seasonally persistent signals over Western India, northeast India, and eastern land regions adjacent to the Western Ghats. The seasonally persistent mode shows a strong relationship with the equatorial central Pacific Ocean SSTs and a moderate correlation with the Indian and Atlantic Ocean SSTs. The seasonally persistent mode contributes largely to the seasonal precipitation anomalies over the Indian monsoon region. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
30. Does increasing the spatial resolution in dynamical downscaling impact climate change projection of Indian summer monsoon, population and GDP?
- Author
-
Jayasankar, C. B., Rajendran, K., and Sajani, Surendran
- Subjects
DOWNSCALING (Climatology) ,CLIMATE change ,ATMOSPHERIC models ,GROSS domestic product ,CLIMATOLOGY ,CLIMATE change mitigation - Abstract
High-resolution regional climate model (RCM) simulations are found to be very useful in deriving realistic climate change projection information. This study uses high-resolution dynamical downscaling framework (CCSM4-WRF) for India. To delineate the advantage of high resolution, we compared the results of 9-km resolution CCSM4-WRF simulations against the 50-km resolution RCM simulations under Coordinated Regional Climate Downscaling Experiment-South Asia (CORDEX-SA) program. Quantitative estimations show that majority of CORDEX-SA models exhibit large dry bias (< − 4 mm/day) and low pattern correlation coefficient (PCC) over the Western Ghats (WG). Mean climatology of Indian summer monsoon (ISM) rainfall simulated by high-resolution CCSM4-WRF outperforms the CORDEX-SA RCMs with low negative biases (~ 1 mm/day) and high PCC (≥ 0.755). This skill of CCSM4-WRF provides better confidence in its future projection at local scale. CCSM4-WRF projects future intensification of monsoon rainfall over most parts of India and reduction over southern WG, which is consistent with recent observed trends, but none of the CORDEX-SA RCMs could simulate this rainfall reduction. For all-India rainfall, ensemble mean of CORDEX-SA models projects an increase by 1.3 ± 0.9 mm/day and CCSM4-WRF projects 0.67 mm/day. Projected changes in socioeconomic variables such as population and gross domestic product (GDP) exhibit future enhancement over most parts of India but with spatial heterogeneity. Shared socioeconomic pathways scenarios show pronounced future population growth over Indian coastal areas and large enhancement in productivity over urban areas. Therefore, climate change projection information of ISM rainfall, together with enhanced future population and GDP, is useful for taking necessary steps for adaptation and mitigation in a sustainable manner. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
31. Workshop on Western Ghats: Evolution and environmental issues.
- Author
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Tiwari, V., Ajayakumar Varma, R., and Padmalal, D.
- Subjects
CLIMATE change conferences ,RESOURCE management ,ENVIRONMENTAL geotechnology ,BIODIVERSITY - Abstract
Information about workshop "Western Ghats; Evolution and environmental issues" organised by research centre National Centre for Earth Science Studies (NCESS) on 1-2 January 2016 is presented. Topic included understanding knowledge gap between geoenvironmental issues, geological evolution and resource management of Western Ghat. Workshop featured three technical seasons including theme Western Ghats-A climate regulator, discussion over presented papers and forestry of Western Ghats.
- Published
- 2016
- Full Text
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32. Ambient air characteristics of biogenic volatile organic compounds at a tropical evergreen forest site in Central Western Ghats of India.
- Author
-
Tripathi, Nidhi, Sahu, L. K., Patel, Kashyap, Kumar, Ashwini, and Yadav, Ravi
- Subjects
VOLATILE organic compounds ,TROPOSPHERIC ozone ,ATMOSPHERIC chemistry ,PROPENE ,CHEMICAL precursors ,AIR sampling ,PROPANE as fuel ,TROPICAL forests - Abstract
Non-methane volatile organic compounds (NMVOCs) play key roles in local and regional atmospheric chemistry as precursors for the production of ozone and secondary organic aerosols. Ambient air C
2 -C5 NMVOCs were measured at a tropical forest site in the central Western Ghats and urban site of Udaipur in India during the late monsoon period of 2016–17 and 2015, respectively. In the Western Ghats, air samples were collected from the protected Bhagwan Mahaveer Sanctuary. Ethene, propene, and isoprene were the dominant biogenic compounds with mean concentrations of 4.8 ± 2, 1.6 ± 0.66 and 1.05 ± 0.43 ppb, respectively. The concentrations of anthropogenic compounds such as propane and pentane were significantly lower than those of light alkenes. The contributions of ethene and propene among different NMVOCs were ~ 44 and 14%, respectively. However, the contributions of isoprene were highly variable of 3–22%. The tight correlation (r2 = 0.90) between the mixing ratios of ethene and propene and their ratio indicates their common formation and emission mechanisms. The molar emission ratio of ethene/propene (2.9 ± 0.17 ppb ppb−1 ) was comparable to those measured at other biogenic sites of Asia while higher than those reported for mid-latitude sites. The concentrations of light alkenes and isoprene at the Western Ghats were 4–5 times higher than those measured in an urban environment in the same season. The higher ozone formation potentials and Propylene-Equivalent concentrations of alkenes and isoprene than those of other NMVOCs indicate important implications of biogenic emissions on ozone photochemistry in the forest regions of India. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
33. Unified model rainfall forecasts over India during 2007–2018: Evaluating extreme rains over hilly regions.
- Author
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Sharma, Kuldeep, Ashrit, Raghavendra, Kumar, Sushant, Milton, Sean, Rajagopal, Ekkattil N, and Mitra, Ashis K
- Subjects
NUMERICAL weather forecasting ,FORECASTING ,FALSE alarms ,RAINSTORMS - Abstract
Prediction of heavy/extreme rains is still a challenge, even for the most advanced state-of-the-art high-resolution Numerical Weather Prediction (NWP) modelling systems. Hydrological models use the rainfall forecasts from the NWP models as input. This study evaluates the performance of the UK Met Office Unified Model (UM) in predicting the rainfall exceeding 80th and 90th percentiles. Such high rainfall amounts occur over the Western Ghats (WGs) and North East (NE) India mainly due to the forced ascent of air parcels. Apart from the significant upgrades in the UM's dynamical core, the model features an increased horizontal grid (40–10 km) and vertical resolution (50–70 levels). The prediction skill of heavy rainfall events improves with an increased horizontal resolution of the model. The probability of detection (POD), false alarm ratio (FAR), and critical success index (CSI) are the verification metrics used. As per these metrics, model rainfall forecasts have improved during 2007–2018 (increase in CSI from 0.29 to 0.38, POD from 0.45 to 0.55, and decrease in FAR from 0.55 to 0.45). Additionally, to verify extreme and rare events, the symmetric extremal dependence index (SEDI) is also used. SEDI also shows an increase from 0.47 to 0.62 and 0.16 to 0.41 over WGs and NE India during the study period, suggesting an improved skill of predicting heavy rains over the mountains. The improved forecast performance is consistent and relatively higher over WGs than over NE states. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
34. Landslide characterization using active and passive seismic imaging techniques: a case study from Kerala, India.
- Author
-
Chávez-García, Francisco J., Natarajan, Thulasiraman, Cárdenas-Soto, Martín, and Rajendran, Kusala
- Subjects
IMAGING systems in seismology ,LANDSLIDES ,SEISMIC prospecting ,SOIL depth ,MICROSEISMS ,CASE studies ,PROPERTY damage - Abstract
The unusually intense precipitations of the 2018 monsoon triggered numerous landslides in the Western Ghats region, southwest of India. Although the landslides caused no casualties, significant damage to property and infrastructure was observed. We present, as a case study, the results of active and passive seismic prospecting at two of those landslides with the goal of characterizing them, in a first application of shallow seismic exploration to landslides in the region. Our deployments included both sites perturbed by the landslides and unperturbed slopes adjacent to them with the purpose of identifying possible structural differences between slopes that underwent landsliding from slopes that were not affected. We analyze seismic sections obtained using the multi-channel analysis of surface waves technique and compare the results with seismic noise analyzed using seismic interferometry. We show that different analyses give similar results. The lateral variations observed in the shear-wave velocity distribution below the different profiles are well correlated with dominant frequency determined from seismic noise horizontal-to-vertical spectral ratios. Our measurements were taken after the landslides occurred. In hindsight, our results suggest that soil thickness played a major role in the triggering of landslides. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
35. Inorganic Ionic Composition of Rainwater at a High Altitude Station over the Western Ghats in Peninsular India.
- Author
-
Waghmare, V. V., Aslam, M. Y., Yang, L., Safai, P. D., and Pandithurai, G.
- Subjects
ALTITUDES ,RAINWATER ,FOSSIL fuels ,SEA level ,BIOMASS burning ,AIR masses ,MATRIX decomposition ,DUST - Abstract
This study investigates chemical composition of rainwater (RW) and its contribution from different sources collected over the period of two years (2016 and 2017) at a high altitude location (1380 m above mean sea level) located at Mahabaleshwar situated in the Western Ghats in Peninsular India. The volume weighted mean pH of RW was found to vary between 4.57 and 7.51 (average 5.95) indicating overall alkaline nature of the RW. Prominent ionic species in the RW were Ca
2+ (25%), Na+ (19%), Cl− (23%), SO4 2− (10%), and Mg2+ (9%) with NH4 + , NO3 − and K+ together forming about 8% of ionic composition. Moreover, ample presence of dust source (Ca2+ ) was found that acted as a major neutraliser to the acidic ions. The order of Neutralisation Factor of ions was Ca2+ > Mg2+ > NH4 + . In addition, a strong correlation between Na+ and Cl− (r ≈ 0.99) further suggested substantial supplement of marine (NaCl) component to the RW. The impact of local anthropogenic activities such as fossil fuel/biomass burning was observed apart from some contribution from the long-range transport. The high contribution of non-sea salt fractions to Ca2+ , SO4 2− , Mg2+ and K+ showed a substantial effect of crustal and continental air masses. Results of source apportionment for the RW composition by using the Positive Matrix Factorization technique indicated four factors i.e. Marine and long range transport (Na+ , Cl− ), crustal (Ca2+ , Mg2+ ), emissions from the fossil fuel and biomass burning (NO3 − , SO4 2− ) and the agriculture/farming activities (NH4 + ). [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
36. In silico docking studies of α-amylase inhibitors from the anti-diabetic plant Leucas ciliata Benth. and an endophyte, Streptomyces longisporoflavus.
- Author
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Akshatha, Jaginakere Vasanthkumar, SantoshKumar, Hulikal Shivashankara, Prakash, Harishchandra Sripathy, and Nalini, Monnanda Somaiah
- Subjects
AMYLASES ,CILIATA ,BINDING energy ,STREPTOMYCES ,HOST plants ,HYDROGEN bonding interactions - Abstract
In this investigation, potential inhibitors of α-amylase, one of the key regulatory enzymes in diabetes were characterized from the methanolic extract of Leucas ciliata Benth. (Lamiaceae), a traditional medicinal plant of the Western Ghats, southern India and the ethyl acetate extract of Streptomyces longisporoflavus (JX965948), an endophytic actinomycete isolated from the stem fragments of L. ciliata, by Gas Chromatography and Mass Spectroscopy (GC–MS) technique followed by molecular docking studies. Forty-four compounds were detected in the solvent extracts of the host plant and the endophyte, respectively. These compounds were selected as ligands for the receptor α-amylase in the molecular docking studies using PyRx software (0.8 V) for the inhibition of α-amylase activity. The ligands were ranked based on the binding energies ranging between − 3.1 and − 10.1 kcal/mol. Three ligands from the host plant extract, viz., Topotecan (PNo_7), Cathine (PNo_17) and 2,5-dimethoxy-4-(methylsulfonyl)amphetamine (PNo_18), depicted good binding energies of − 5.2 to − 7.8, respectively, whereas seven compounds from the endophyte extract showed binding energies in the range of − 4.7 to − 10.1, respectively. The standard α-amylase inhibitor Acarbose™ depicted binding energy of − 9.2 kcal/mol. All ligands were subjected to lead-likeliness property using Lipinski's rule of five. On the basis of the hydrogen bonding interactions with the receptor, and chemoinformatics analysis for drug-likeliness, one ligand, Topotecan (PNo_7) from the host plant was identified as the potential α-amylase inhibitor. This is the first attempt to identify alkaloid and flavonoid compounds as the α-amylase inhibitors from the host plant and its endophyte simultaneously. The molecular docking analyses presented in this study could lead to the development of potent α-amylase inhibitors helpful in the treatment of diabetes. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
37. In vitro strategies for the conservation of Indian medicinal climbers.
- Author
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Deepa, A. V. and Thomas, T. Dennis
- Subjects
MEDICINAL plants ,RANUNCULACEAE ,SAPINDACEAE ,ANGIOSPERMS ,CUCURBITACEAE ,CLIMBING plants - Abstract
Climbers are plants with weak stems that require support to grow upright. This group of plants develops various climbing mechanisms, classified as tendrillar, twiners, scramblers, clinging, adhesive and woody climbers (lianas). Although climbers are predominantly angiosperms, some are ferns, and one gymnosperm member Gnetum is included in this category. The angiosperm families mainly composed of climbers include Cucurbitaceae, Convolvulaceae and Dioscoreaceae. India's biodiversity includes two regions, the Western Ghats and the Eastern Himalayas. According to the Botanical Survey of India, of approximately 18,000 species of angiosperms in India, 8000 of them are medicinal plants and several of them are climbers. Many climbers are medicinally important and used as herbal remedies in traditional systems of Indian medicine, including Ayurveda, Sidha and Unani. Several active phytochemicals from different parts of these plants are isolated and used as medicine either alone or in combination with other compounds. Unfortunately, many of these plants are under the threat of extinction due to habitat depletion and overexploitation and conservation efforts are required to ensure their long-term stability. In this review, we discuss in vitro propagation and conservation strategies for Indian medicinal climbers from diverse families including Fabaceae, Aristolochiaceae, Asparagaceae, Caesalpiniaceae, Sapindaceae, Asclepiadaceae, Vitaceae, Ranunculaceae, Menispermaceae, Colchicaceae, Apocynaceae, Rubiaceae, Passifloraceae, Stemonaceae, Euphorbiaceae and Cucurbitaceae due to their high medicinal value. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
38. Identification of vegetation responses to soil moisture, rainfall, and LULC over different meteorological subdivisions in India using remote sensing data.
- Author
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Bhimala, Kantha Rao, Rakesh, V., Prasad, K. Raghavendra, and Mohapatra, G. N.
- Subjects
SOIL moisture ,NORMALIZED difference vegetation index ,REMOTE sensing ,RAINFALL ,PRINCIPAL components analysis - Abstract
Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI) data were analyzed to study the vegetation dynamics over different meteorological subdivisions in India for the period 2000–2016. Soil moisture (SM), rainfall (RF), and land use land cover (LULC) data were analyzed to identify the climatic and anthropogenic drivers that cause vegetation changes at the subdivision scale. Principal component analysis and MK (Mann-Kendall) test showed significant greening trend over semi-arid regions of Northwest India (NWI) and South India (SI) while slight browning trend seen over some of the subdivisions in Indo-Gangetic (IG) plains and Western Ghats (WG). It is found that the NDVI has superior correlation with soil moisture compared with rainfall and the croplands (CL) found to have significant increasing trend over the NWI and SI. Increasing trend in soil moisture over the NWI and SI may have contributed to increase in CL area and the greening trend. Over IG plains, the NDVI showed moderate correlation with SM and RF, and the greening trend (browning trend) in some regions can be attributed to increase in natural vegetation mosaic (decrease of CL). The NDVI has shown browning trend over the core monsoon regions of Madhya Pradesh (an increase of barren lands over west MP and decrease of CL over east MP) and Western Ghats (significant decrease of CL over Konkan and Goa). This study revealed that the soil moisture and LULC changes are the major driving factors for the vegetation changes over majority of the subdivisions in India. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
39. Assessment of climate warming in the Western Ghats of India in the past century using geothermal records.
- Author
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Jha, Srinidhi, Bharti, Birendra, Reddy, Dontireddy Venkat, Shahdeo, Pragya, and Das, Jew
- Subjects
CLIMATE change ,ATMOSPHERIC temperature ,SURFACE temperature ,EARTH temperature ,CLIMATOLOGY - Abstract
Temperature-depth profiles of boreholes of a region can be analysed to estimate the past variations in climate. Perturbations over the surface ground temperature are imparted deep into the Earth's subsurface. Western Ghats regions of India are considered to be one of the most ecologically rich regions and also play a crucial role in deciding the climatological characteristics of the country. This study quantifies the possible climate warming or cooling in the past century in the Western Ghats using temperature-depth profiles of five boreholes in a depth range of 140–198 m located in Koyna region (17.38° N, 73.74° E) of Maharashtra state, India. The analysis shows that there has been a significant warming of 0.8 ± 0.2 °C over the past 100 years in the region. The inferred warming is comparable with the trends of meteorological records of the area which yields an increasing trend of 0.56 °C in the surface air temperature (SAT). For further validation of results, a combined study of borehole temperature profiles and surface air temperature (SAT) profiles was done which showed that the period was warmer than the earlier long-term temperature records of the region by 0.8 °C. This pre-observational mean (POM) value seems to be consistent with previously studied POMs over India. This study provides a 'true estimate' of climate change and can be used as a robust technique to reconstruct the past climate warming. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
40. The deployment of deep-earth sensor probes for landslide detection.
- Author
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Ramesh, Maneesha and Vasudevan, Nirmala
- Subjects
RISK assessment for landslides ,WIRELESS sensor networks ,ELECTRONIC probes ,EMERGENCY management ,EQUIPMENT & supplies - Abstract
In this paper, we present a state-of-the-art wireless sensor network (WSN) of deep-earth probes (DEPs) that has been deployed to monitor an active landslide in the Western Ghats mountain range of South India. While India has one of the highest incidences of landslides and landslide-induced fatalities-primarily in the Himalayas of North India and in the Western Ghats of Central and South India-our study is perhaps the first comprehensive attempt to instrumentally detect landslides in the Western Ghats. Wireless networks have enabled us, since June 2009, to continuously monitor the deployment site in real time and from anywhere around the globe. There have been a few earlier landslide monitoring WSNs using accelerometers in Emilia Romagna Apennines, Italy; global navigation satellite system (GNSS) sensors to monitor the Hornbergl landslide, Austria; and vibrating wire stress sensors to monitor a slope in China. We improved upon these WSN systems by incorporating a variety of sensors-piezometers, dielectric moisture sensors, strain gauges, tiltmeters, a geophone, and a weather station-and installing some of these sensors as deep as 20 m below the ground surface. We present the salient aspects of the field deployment of DEPs: the selection of sensors and their incorporation in DEPs, the methodology we used in embedding these DEPs into the soil, and a few of the key aspects of the wireless sensor network. We also present a description of the deployment site and some of the results of geotechnical investigations carried out on borehole corings. Finally, we present the more interesting field data collected from the monitoring system during a rainy season in July and August 2009. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
41. History of landslide susceptibility and a chorology of landslide-prone areas in the Western Ghats of Kerala, India.
- Author
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Kuriakose, Sekhar, Sankar, G., and Muraleedharan, C.
- Subjects
LANDSLIDE hazard analysis ,DEBRIS avalanches ,MOUNTAIN climate ,ANTHROPOGENIC effects on nature ,LAND use & the environment ,DEFORESTATION ,RAINFALL frequencies - Abstract
Kerala is the third most densely populated state in India. It is a narrow strip of land, of which 47% is occupied by the most prominent orographic feature of peninsular India, The Western Ghats mountain chain. The highlands of Kerala experience several types of landslides, of which debris flows are the most common. They are called "Urul Pottal" in the local vernacular. The west-facing Western Ghats scarps that runs the entire extent of the mountain system is the most prone physiographic unit for landslides. The highlands of the region experience an annual average rainfall as high as 500 cm through the South-West, North-East and Pre-Monsoon showers. A survey of ancient documents and early news papers indicates a reduced rate of slope instability in the past. The processes leading to landslides were accelerated by anthropogenic disturbances such as deforestation since the early 18th century, terracing and obstruction of ephemeral streams and cultivation of crops lacking capability to add root cohesion in steep slopes. The events have become more destructive given the increasing vulnerability of population and property. Majority of mass movements have occurred in hill slopes >20° along the Western Ghats scarps, the only exception being the coastal cliffs. Studies conducted in the state indicates that prolonged and intense rainfall or more particularly a combination of the two and the resultant pore pressure variations are the most important trigger of landslides. The initiation zone of most of the landslides was typical hollows generally having degraded natural vegetation. A survey of post-landslide investigation and news paper reports enabled the identification of 29 major landslide events in the state. All except one of the 14 districts in the state are prone to landslides. Wayanad and Kozhikode districts are prone to deep seated landslides, while Idukki and Kottayam are prone to shallow landslides. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
42. Improved rainfall threshold for landslides in data sparse and diverse geomorphic milieu: a cluster analysis based approach.
- Author
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Sajinkumar, K. S., Rinu, S., Oommen, T., Vishnu, C. L., Praveen, K. R., Rani, V. R., and Muraleedharan, C.
- Subjects
CLUSTER analysis (Statistics) ,LANDSLIDES ,RAINFALL ,SOIL depth ,MASS-wasting (Geology) ,CONTENT analysis ,MONSOONS - Abstract
Rainfall-triggered landslides are the most common type of mass movement seen along the tropical belt due to the prevalence of monsoons. These landslides can be forecasted by understanding the spatial and temporal rainfall distribution patterns, and subsequent generation of rainfall threshold (RT). However, deriving a regional RT in a geologically, geographically and physiographically diverse milieu is a formidable task. The data on spatial and intra-seasonal variability of monsoons can be widely dispersed in such diversified terrains. Clustering analysis provides a promising approach to handle such widely dispersed data. This study intends to develop a methodology using 2-stage clustering process to create RT in such terrains by using daily rainfall versus antecedent rainfall and rainfall versus antecedent rainfall versus soil depth. Sixteen rainfall-induced landslides, located in different terrains in the Western Ghats of India, were subjected to this analysis. Majority of the landslides were modeled, and different RTs were derived for different conditions. The landslides belong to four different classes, viz., landslides occurring at steep slopes; those occurring at knickpoints of highland and midland; in the plateau region and others characterized by a thin veneer of soil. Out of 16 landslides subjected to RT, this method was able to model 13 landslides with a success rate of 81.25%, which is a fair figure. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
43. Antibacterial metabolites from Bipolaris specifera, an endophytic fungus from the endemic medicinal plant, Zingiber nimmonii (J. Graham) Dalzell.
- Author
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Das, Madhuchhanda, Prakash, Harishchandra Sripathy, and Nalini, Monnanda Somaiah
- Subjects
ENDOPHYTIC fungi ,ENDEMIC plants ,MEDICINAL plants ,ZINGIBER ,ENTEROBACTER aerogenes ,FATTY acid esters ,ESTERS ,ETHYL acetate ,BIPOLARIS - Abstract
Eleven fungal endophytes were isolated from the plant parts of Z. nimmonii (J. Graham) Dalzell, an endemic species of the Western Ghats, India, a biodiversity hotspot area. The endophytic isolates were characterized by the sequencing of the Internal Transcribed Spacer (ITS) regions and designated as strains by depositing ITS sequences in the Gen Bank sequence database. All the strains were cultured in Potato Dextrose broth (PDB, 500 mL) contained in Erlenmeyer flasks to obtain the secondary metabolites. The culture filtrate was extracted with ethyl-acetate (EA) three times and concentrated by flash evaporation to obtain EA crude dry extract. The strains were evaluated for the antibacterial potentials against six pathogenic bacterial strains viz., Bacillus subtilis (MTCC 121), Staphylococcus aureus (MTCC 7443) Pseudomonas aeruginosa (MTCC 7093), Escherichia coli (MTCC 729), Enterobacter aerogenes (MTCC 111) and Klebsiella pneumoniae (MTCC 661). Nine endophytic fungal extracts except Alternaria consortiale and Hypocrea lixi showed inhibitory activities against at least two of the six test bacterial strains. Bipolaris specifera (KM114290) exhibited the highest inhibition zones ranging from 15.1 ± 0.3 to 26.7 ± 1.1 mm (diameter), against all six test bacteria in the agar disk diffusion assay, and with Minimum Inhibitory Concentrations (MIC's) of 0.04–0.14 mg/mL, followed by Aspergillus terreus. B. specifera extract was therefore selected and characterized for the identification of antibacterial compounds by chromatographic techniques. Seven antibacterial compounds viz., (1) Bicyclo[3.2.0]heptan-2-one, 6-hydroxy-5-methyl-6-vinyl; (2) Adipic acid divinyl ester; (3) 1,4-Naphthoquinone, 6-acetyl-2,5-dihydroxy; (4) Decanedioic acid, 3,7-dimethyl ester; (5) (Z)-4-Hexenoic acid 2-acetyl-2-methyl-ethyl ester and (6) Butanoic acid 2-acetyl-3-methyl-methyl ester and (7) Caffeic acid, were identified through liquid and gas chromatography. These compounds are mainly volatile esters of fatty acids, phenolics and adipic acid found rare in nature. This study envisages the possible drug discovery using endophytes from traditional and endemic medicinal species. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
44. Antibacterial metabolites from Bipolaris specifera, an endophytic fungus from the endemic medicinal plant, Zingiber nimmonii (J. Graham) Dalzell.
- Author
-
Das, Madhuchhanda, Prakash, Harishchandra Sripathy, and Nalini, Monnanda Somaiah
- Subjects
ENDOPHYTIC fungi ,ENDEMIC plants ,MEDICINAL plants ,ZINGIBER ,ENTEROBACTER aerogenes ,FATTY acid esters ,ESTERS ,ETHYL acetate ,BIPOLARIS - Abstract
Eleven fungal endophytes were isolated from the plant parts of Z. nimmonii (J. Graham) Dalzell, an endemic species of the Western Ghats, India, a biodiversity hotspot area. The endophytic isolates were characterized by the sequencing of the Internal Transcribed Spacer (ITS) regions and designated as strains by depositing ITS sequences in the Gen Bank sequence database. All the strains were cultured in Potato Dextrose broth (PDB, 500 mL) contained in Erlenmeyer flasks to obtain the secondary metabolites. The culture filtrate was extracted with ethyl-acetate (EA) three times and concentrated by flash evaporation to obtain EA crude dry extract. The strains were evaluated for the antibacterial potentials against six pathogenic bacterial strains viz., Bacillus subtilis (MTCC 121), Staphylococcus aureus (MTCC 7443) Pseudomonas aeruginosa (MTCC 7093), Escherichia coli (MTCC 729), Enterobacter aerogenes (MTCC 111) and Klebsiella pneumoniae (MTCC 661). Nine endophytic fungal extracts except Alternaria consortiale and Hypocrea lixi showed inhibitory activities against at least two of the six test bacterial strains. Bipolaris specifera (KM114290) exhibited the highest inhibition zones ranging from 15.1 ± 0.3 to 26.7 ± 1.1 mm (diameter), against all six test bacteria in the agar disk diffusion assay, and with Minimum Inhibitory Concentrations (MIC's) of 0.04–0.14 mg/mL, followed by Aspergillus terreus. B. specifera extract was therefore selected and characterized for the identification of antibacterial compounds by chromatographic techniques. Seven antibacterial compounds viz., (1) Bicyclo[3.2.0]heptan-2-one, 6-hydroxy-5-methyl-6-vinyl; (2) Adipic acid divinyl ester; (3) 1,4-Naphthoquinone, 6-acetyl-2,5-dihydroxy; (4) Decanedioic acid, 3,7-dimethyl ester; (5) (Z)-4-Hexenoic acid 2-acetyl-2-methyl-ethyl ester and (6) Butanoic acid 2-acetyl-3-methyl-methyl ester and (7) Caffeic acid, were identified through liquid and gas chromatography. These compounds are mainly volatile esters of fatty acids, phenolics and adipic acid found rare in nature. This study envisages the possible drug discovery using endophytes from traditional and endemic medicinal species. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
45. Depth-wise distribution of soil-carbon stock in aggregate-sized fractions under shaded-perennial agroforestry systems in the Western Ghats of Karnataka, India.
- Author
-
Chatterjee, Nilovna, Nair, P. K. Ramachandran, Nair, Vimala D., Viswanath, Syam, and Bhattacharjee, Abhishek
- Subjects
SOIL structure ,DECIDUOUS forests ,HISTOSOLS ,CARBON sequestration ,TEA ,INCEPTISOLS - Abstract
Growing shade-tolerant perennial crops under trees is an economically attractive land-use activity in the tropics; but the importance of these systems in facilitating ecosystem services such as soil carbon sequestration is seldom recognized. We assessed soil carbon stock at various depths (0–10, 10–30, 30–60, and 60–100 cm) in shaded perennial agroforestry systems (AFS) in Koppa (12°54′N, 75°04′E), Karnataka, India. The systems were coffee (Coffea canephora) under Grevillea robusta trees (Coffee + Grevillea), coffee under a mixture of shade trees (Coffee + Mixed Shade), tea (Camellia sinensis) under Grevillea robusta (Tea + Grevillea), a traditional smallholder farm with several common crops grown together (Homegarden), and a native moist deciduous forest (Forest). Four replicated composite soil samples were collected from each system for each depth class. Soil organic carbon (SOC) stock in three soil aggregate fractions (2000–250 µm, 250–53 µm, and < 53 µm) as well as in the whole soil was determined. The SOC stock to 1-m depth were 172.3 and 142.4 Mg C ha
−1 under Forest and Coffee + Grevillea, respectively, and the lowest (89.3 Mg C ha−1 ) under Homegarden. No significant differences were noted in SOC within the silt + clay fraction (< 53 µm) beyond 60 cm depth under Forest and other shaded AFS. Fitting a fixed-effects model, we found out that all three factors considered for this study: depth, aggregate size and treatment (land use system) had significant interaction effects on SOC stocks. The results show that deep rooted, tree-based systems, have higher total soil C stocks and more C in the smallest (< 53 µm) soil fractions indicating the recalcitrant (longer-term storage) nature of C and implying consequent ecosystem benefit of reduced chances for soil C release back to the atmosphere. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
46. Bioactive and Biocompatible Nature of Green Synthesized Zinc Oxide Nanoparticles from Simarouba glauca DC.: An Endemic Plant to Western Ghats, India.
- Author
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Hemanth Kumar, N. K., Murali, M., Satish, A., Brijesh Singh, S., Gowtham, H. G., Mahesh, H. M., Lakshmeesha, T. R., Amruthesh, K. N., and Jagannath, Shobha
- Subjects
ENDEMIC plants ,NANOPARTICLES ,PLANT extracts ,NATURE ,ENVIRONMENTAL reporting - Abstract
Zinc-oxide nanoparticles (ZnO-NPs) synthesized from plant extracts are considered to possess superior biological activities compared to chemically synthesized nanoparticles and are of immediate interest to pharmaceutical and agriculture industries. The current study reports the green synthesis of ZnO-NPs from the aqueous leaf extract of Simarouba glauca for the first time. The physico-chemical characterization revealed hexagonal shaped nanoparticles with a size of ~ 17 to 37 nm calculated by Scherrer's formula with a purity of 98.51%. The FT-IR results confirmed that functional groups present in the plant extract had coagulated well to form a metal oxide during the synthesis process. The antioxidant potential of green synthesized ZnO-NPs evaluated by different methods revealed significant (p ≤ 0.05) radical scavenging activity (5% to 59%) with IC
50 value falling between 400 and 500 µg mL−1 among the test methods. The green synthesized nanoparticles also inhibited the mitotic cell division up to 17.46% with increase in concentration. Further, the haemolytic assay by spectroscopic analysis affirmed the biocompatible nature of the nanoparticles which was also evidenced through SEM studies. The present findings indicate that the green synthesized ZnO-NPs from S. glauca possess antioxidant and antimitotic properties apart from possessing biocompatible nature to RBCs thereby warranting in vivo studies. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
47. Management of Forest-Dwelling and Urban Species: Case Studies of the Lion-Tailed Macaque (Macaca silenus) and the Bonnet Macaque (M. radiata).
- Author
-
Singh, Mewa
- Subjects
MACAQUES ,WILDLIFE conservation ,RHESUS monkeys ,VEGETATION management ,HINDU temples ,DECIDUOUS forests ,FRAGMENTED landscapes - Abstract
Species conservation depends on the needs of the species concerned. For example, obligatory forest-dwelling and typically urban primate species require different conservation approaches. Here, I compare the ecology, life history, and behavior of two species of macaques in southern India; review what we know about the conservation challenges for each; and propose conservation measures. Lion-tailed macaques (Macaca silenus) are endemic to the rainforests of the Western Ghats and are endangered as a result of fragmentation of their habitats and low population growth. I recommend identification of contiguous forest habitats for viable lion-tailed macaque populations, improving the quality of their degraded habitats, and the linking of forest fragments with native vegetation as management measures for their conservation. In contrast, the bonnet macaque (M. radiata) is a habitat generalist endemic to southern India, but is losing its range to the relatively larger bodied and more aggressive rhesus macaque (M. mulatta). It is not a typically forest-dwelling species, and its populations are declining drastically in its traditional habitats that include Hindu temples, tourist spots, and roadsides with fruit-bearing trees and agricultural crops. The population has remained stable only where the habitat allows the macaques to forage in scrub jungle and includes a temple where the monkeys can obtain food from visitors. India is dotted with small hillocks with natural scrub or deciduous forest vegetation with one or two Hindu temples, and it appears that such habitats are the most suitable places for the long-term conservation of this species. These two case studies serve as examples of the different approaches needed to conserve forest-dwelling and urban primates, and with appropriate modifications, may inform the conservation of many other species. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
48. Weathering and landslide occurrences in parts of Western Ghats, Kerala.
- Author
-
Sajinkumar, K., Anbazhagan, S., Pradeepkumar, A., and Rani, V.
- Subjects
WEATHERING ,EROSION ,LANDSLIDES ,LOAM soils - Abstract
The climatic condition of Western Ghats has influenced the process of weathering and landslides in this mountainous tract along the southwest coast of India. During the monsoon period, landslides are a common in the Western Ghats, and its intensity depends upon the thickness of the loose unconsolidated soil formed by the process of weathering. Debris landslides with a combination of saprock, saprolite and soil, indicate the role of weathering in landslide occurrences. This paper reports on how the weathering in the windward slope of Western Ghats influences the occurrence of landslides and the factors which accelerate the weathering process. Rock and soil samples were collected from the weathering profile of hornblende gniess and granite gneiss. The chemical analysis and the calculated Chemical Index of Alteration (CIA) indicate the significant weathering and its possible influence on landslide occurrences in the study area. Mainly, the CIA value of lateritic soil and forest loam indicated the extent of high chemical weathering in this region. Rainfall is the dominant parameter influencing the chemical weathering process. In addition, deforestation, land use practices and soil erosion are some of the other important factors accelerating the weathering process and landslide occurrences in the region. The locations of the previous landslides superimposed on geology and soil show that most of the landslide occurrences are associated with the highly weathered zone, particularly lateritic soil and the 'severe' (rock outcrop) erodability zone. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
49. Hydrological response-based watershed prioritization in semiarid, basaltic region of western India using frequency ratio, fuzzy logic and AHP method.
- Author
-
Kadam, Ajaykumar, Karnewar, Animesh S., Umrikar, Bhavana, and Sankhua, R. N.
- Subjects
FUZZY logic ,ANALYTIC hierarchy process ,WATERSHEDS ,RECEIVER operating characteristic curves ,RUNOFF - Abstract
Watersheds from semiarid regions are more sensitive to hydrological processes and sustainability of water resources than humid regions. Hence, it is indispensable to determine the response of watersheds to hydrological processes for water resource management. Thus, the hydrological response-based watershed prioritization study has been undertaken for eight sub-watersheds from semiarid, basaltic region of Western Ghats of India. Intent to this, a novel index has been parameterized using thematic layers such as drainage density, geology, soil, slope, landform classification, land use/land cover, rainfall and runoff (DGSLR). This study evaluates the performance of DGSLR index using three models, namely analytical hierarchy process (AHP), frequency ratio (FR) and fuzzy logic for sub-watershed-wise prioritization. The FR ratio showed the highest value for very high drainage density (8.73) indicating most probability for a high hydrological response. According to AHP weight, most influencing factors to hydrological processes are precipitation (25%), slope (19%) and land use/land cover (14%) followed by landform classification (11%). These three methods are prioritized study area into four classes, i.e., very high, high, moderate and low using area-weighted average method. These models showed that very high-priority area lies near the outlet of the watershed as well as the upper part of the watershed in high to very high priority in all three models. It covers 33.12% of the total area having a high average slope with high drainage density in sub-watersheds 1, 3, 7 and 8. The predictive capability of DGSLR index was computed by the area under the curve (AUC) and receiver operating characteristic (ROC) method, revealed average accuracy for FR method (AUC = 89%) better than AHP method (AUC = 77%) and fuzzy logic (AUC = 76%). This novel index could be used by the water resources researchers and planners in any terrain to understand the hydrological response. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
50. Genetic structure of the rattan Calamus thwaitesii in core, buffer and peripheral regions of three protected areas in central Western Ghats, India: do protected areas serve as refugia for genetic resources of economically important plants?
- Author
-
Ramesha, B. T., Ravikanth, G., Rao, M. Nageswara, Ganeshaiah, K. N., and Shaanker, R. Uma
- Subjects
PROTECTED areas ,GERMPLASM conservation ,PLANT conservation ,POPULATION genetics ,RATTAN ,BUFFER zones (Ecosystem management) - Abstract
Given the increasing anthropogenic pressures on forests, the various protected areas--national parks, sanctuaries, and biosphere reserves--serve as the last footholds for conserving biological diversity. However, because protected areas are often targeted for the conservation of selected species, particularly charismatic animals, concerns have been raised about their effectiveness in conserving nontarget taxa and their genetic resources. In this paper, we evaluate whether protected areas can serve as refugia for genetic resources of economically important plants that are threatened due to extraction pressures. We examine the population structure and genetic diversity of an economically important rattan, Calamus thwaitesii, in the core, buffer and peripheral regions of three protected areas in the central Western Ghats, southern India. Our results indicate that in all the three protected areas, the core and buffer regions maintain a better population structure, as well as higher genetic diversity, than the peripheral regions of the protected area. Thus, despite the escalating pressures of extraction, the protected areas are effective in conserving the genetic resources of rattan. These results underscore the importance of protected areas in conservation of nontarget species and emphasize the need to further strengthen the protected-area network to offer refugia for economically important plant species. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
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