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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]

In this study, the impacts of changes in land use/ land cover (LULC) and climate on surface runoff are investigated in the Kadalundi river basin, Western Ghats, India. Land Change Modeller (LCM) was applied to project the future LULC scenarios in 2030 and 2050. Climate change scenarios of the future time period of near (2011−2040), mid (2041−2070), and far (2071−2099) were procured for Representative Concentration Pathway (RCP) 4.5 and 8.5 emission scenarios from five different general circulation models of coordinated regional downscaled experiment project. The 1988 and 2000 LULC were used for projection of 2014 LULC and validated with actual 2014 LULC. Further, 2000 and 2014 LULC were used for projection of 2030 LULC, and 2014 and 2030 LULC were used to project 2050 LULC. Changes in LULC from 2000 to 2050 are calculated using the transition matrix approach. The impacts of changes in LULC and climate on surface runoff are investigated by the Soil and Water Assessment Tool (SWAT) model. The results showed a decrease in forest and grassland and an increase in agriculture, and urban areas from 2000 to 2050, with an increase in the mean annual surface runoff. For climate change scenarios assessed, mean annual surface runoff in the near, mid, and far would be decreasing under both RCP 4.5 and 8.5 while RCP 8.5 showing more worse condition than RCP 4.5 in the future. The combined effects of changes in LULC and climate showed a decreasing trend in the surface runoff for the near and mid future. Furthermore, the projected results indicate that the surface runoff would be higher in both RCP scenarios during winter and summer; while the monsoon period largely demonstrates a reverse trend. The analysis of combined impacts reveals that the decreasing of surface runoff under RCP 4.5 and 8.5 would be higher in near compared to mid future. [ABSTRACT FROM AUTHOR]

It is widely known that land use/land cover (LULC) changes significantly alter watershed hydrology and sediment yields. The impact, especially on erosion and sedimentation, is likely to be exacerbated in regions dominated by high rainfall patterns such as monsoons. This study analyzed the hydrological responses of LULC changes in terms of streamflow (SF) and sediment yield (SY) in a monsoon-dominated tropical watershed, the Periyar River Watershed (PRW) in Kerala, India. This watershed drains an area of 4793 km2 characterized by an average monsoon rainfall of 2900 mm from June to November. The watershed hydrology and sediment dynamics were simulated using the Soil and Water Assessment Tool (SWAT) model for the impact assessment at the watershed outlet and the sub-watershed level. Historical LULC data were analyzed for 1988, 1992, 2002, and 2016 using the maximum likelihood method, and future LULC changes were projected for 2030, 2050, 2075, and 2100 using the Markov chain–cellular automata technique. Between 1988 and 2016, the urban area increased by 4.13 percent, while plantation and forest coverage decreased by 1.5 percent. At this rate, by 2100, the urban area is expected to grow by 16.45% while plantations and forest area will shrink by 13.7% compared to 1988. The effects of these changes on SF and SY were found to be minimal at the watershed outlet; however, at the spatial scale of sub-watersheds, the changes varied up to 70% for surface runoff and 200% for SY. These findings highlight the potential impacts of LULC changes in a monsoon-dominated watershed and may contribute to the development of successful LULC-based watershed management strategies for prevention of flooding and sediment loss. [ABSTRACT FROM AUTHOR]

Urbanization is one of the main drivers in the conversion of natural habitats into different land use and land cover types (LULC) which threaten the local as well as global biodiversity. This impact is particularly alarming in tropical countries like India, where ~18% of the world's population live, and its ever-growing economy (i.e., industrial development) expanded urban areas by several folds. We undertook this study to examine the impacts of urbanization (i.e., LULC) on terrestrial vertebrates (mammals, birds, reptiles, and amphibians) in the Mumbai Metropolitan Region (MMR), Western Ghats, India. We sampled different habitats ranged from highly disturbed urban areas to less disturbed forested areas. Multiple sampling methods such as quadrat sampling, line transect, point count, and camera trapping were used to quantify the target taxa. We used multi-species occupancy modeling in the Bayesian framework to estimate detection probability and occupancy and to assess the effect of various LULC on different species. All four groups showed a significant negative impact of increasing anthropogenic habitat cover on occupancy. Out of 213 species detected in this study, 96% of mammals, 85% of birds, 93.75% of amphibians, and 69.43% of reptiles showed a negative effect of anthropogenic habitat cover. Evidence suggests that historical and recent human disturbances could have played an important role in transforming this area from semi-evergreen and moist deciduous forest to open, scrubby, dry deciduous, and fire-prone landscape. This might be the reason for the high occupancy of open and degraded forest habitat preferring species in our study area. We recommend species-rich areas in the MMR, e.g., Karnala Bird Sanctuary (KBS) and Prabalgad-Matheran-Malanggad Hill Range (PMMHR), must be conserved through habitat restoration, ecotourism, public awareness, and policymaking. [ABSTRACT FROM AUTHOR]

Transport infrastructure is said to drive development in a region and affect the land use/land cover (LULC) over time. We employ a difference-in-differences (DID) framework to causally examine transport infrastructure as a driver of land use/land cover change (LUCC) using the case study of the Konkan Railway, one of the largest railway projects in post-independence India. Using multi-period multispectral satellite data, we obtained the basic LULC classes for the DID and spatio–temporal analysis. The findings suggest that the Konkan Railway led to an increase in built-up land cover and open spaces at the expense of the agricultural land cover, but did not adversely affect forest cover. This result is consistent all along the 760 km long railway. The study contributes to the emerging literature on the land use impacts of railways and underscores the importance of implementing environmental management measures. [ABSTRACT FROM AUTHOR]

Streamflow can be affected by a number of aspects related to land use and can vary promptly as those factors change. Urbanization, deforestation, mining, agricultural practices and economic growth are some of the factors related to these land use changes which alter the stream flow. In the present study, the impact of land use land cover change (LULC) on stream flow is studied by using SWAT model for Tungabhadra river basin, located in the state of Karnataka, India. Tungabhadra river originates in the Western Ghats of Karnataka and flows towards north-east and joins the river Krishna. The land use maps of 1993, 2003 and 2018 are used for assessing the stream flow changes with respect to LULC. Calibration and validation of the model for streamflow was carried out using the SUFI-2 algorithm in SWAT-CUP for the years 1983–1993 and 1994–2000 respectively. Statistical parameters namely Coefficient of Determination (R2) & Nash–Sutcliffe (N-S) were used to assess the efficiency and performance of the SWAT model. It was found that the observed and simulated streamflow values are closely matching, which in turn projects that the model results are acceptable. The calibrated model was used for simulation of future dynamic land use scenario to assess the impact on streamflow. The results can be used for conservation of water and soil management. [ABSTRACT FROM AUTHOR]