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The basin of the small river studied here (the Vezelka River, Belgorod Oblast of European Russia) is located within an urban area (22% of the basin). This circumstance determines its specificity as an object of synergetic anthropogenic impact. The purpose of the work was to develop and test approaches to the integral assessment of the hydroecological situation both in the watershed and riparian zones based on hydrological, hydrochemical, and hydrobiological data and estimates of soil erosion, river water quality, and the pollution of river bottom sediments. The selection of the Vezelka River and its watershed for the study was due to the presence there of two water intakes for a town with a population of 2439 people per sq. km, repeated bottom deepening in the riverbed, and the fact that there is a single regional small-river hydrological station (although there are 567 rivers < 25 km long in Belgorod Oblast). Analysis for 1951–2021 showed a steady decline in water discharge since 1991; thus, over the past three decades, the discharge has decreased by 2.4 times. The reduction in the length of the river network of the study region by 38% over the past 250 years and the assignment of water (at 10 gauging stations) to 3–4 quality classes (extremely and heavily polluted) indicated the exhaustion of the possibilities for the self-purification of the river water. These estimates for large and medium rivers were clearly confirmed by the investigation of the water in the small river studied. In the summer low-water periods, the maximum allowable concentrations in fishery water bodies were exceeded by 2–10 times in terms of Cu, Fe, ammonium, oil, and biochemical oxygen demand. The reconstruction of the floodplain–channel subsystem of river–valley landscapes was substantiated as the final stage of the concept of basin nature management, replacing the continuous deepening of the channel without proper erosion control measures in the watershed area and the organization of buffer zones along the river banks.

Social distance memaksa semua sektor untuk berinovasi, salah satunya pada dunia pendidikan. Dimana pemerintah meminta sekolah untuk melaksanakan pembelajaran jarak jauh dengan menggunakan pembelajaran daring. Kegiatan pembelajaran daring jauh lebih sulit dilakukan daripada pembelajaran tatap muka dikarenakan harus memanfaatkan beberapa teknologi dalam penerapannya serta mampu menggunakan model, strategi, media, bahan ajar dan penilaian yang tepat. Keadaan ini menjadi tantang tersendiri terlebih pada guru. Maka perlu kesiapan yang optimal dalam pelaksanaan pembelajaran daring terutama di sekolah dasar yang berada di lingkungan DAS (Daerah Aliran Sungai). Penelitian ini menggunakan pendekatan kualitatif deskriptif yang bertujuan untuk mendeskripsikan dan menggambarkan kesiapan guru dalam pembelajaran daring. Subjek penelitian yang dilakukan ke 24 orang guru dari tiga sekolah dengan menggunakan teknik random sampling. Hasil penelitian yang didapatkan dari pelaksanaan pembelajaran dari di ketiga sekolah ini ialah masih kurang optimal persiapan yang dilakukan oleh guru, dikarenakan beberapa faktor, yakni lingkungan masyarakat dan orang tua/wali siswanya yang kurang mendukung, sarana dan prasarana di sekolah yang masih kurang dan SDM yang ada di sekolah yang ada beberapa belum mampu melaksanakan kegiatan pembelajaran daring dengan baik. Sehingga nanti diharapkan ada perbaikan dan solusi pemecahan masalah dari kurang optimalnya persiapan pelaksanaan pembelajaran daring ini di beberapa sekolah.

Groundwater in arid areas is critical for drinking water supplies, irrigated agriculture, and the preservation of terrestrial ecosystems. In the semi-arid region of Guenfouda, shallow aquifers are vital for human habitation and agriculture. Many settlements acquire their water from wells and springs. However, these wells are particularly susceptible to seasonal fluctuations and may be depleted during dry periods. Therefore, a deeper understanding of the hydrogeology of deep aquifers is required. Using analysis of geologic and hydrogeologic data in a GIS environment, this study examined the efficiency of the gravity model in investigating the structure of deep aquifers. A combination of filtering techniques was applied on the gravity map. The developed model shows the general configuration of the Jurassic aquifer, which gradually dips to the north and northeast to a depth of about 2280 m. Statistical analysis revealed considerable spatial coherence between fractures and compartments of the aquifer. Consequently, the structural model obtained from gravity data can greatly improve our understanding of the aquifer structure in the survey area.

This study aims to assess Flood susceptibility and flood hazard levels and obtain the distribution of hazard levels and flood hazards in the Woyla watershed, Aceh Province. This research design generally uses a descriptive survey method and divide into several stages, such as data collection, data processing, data presentation, and delivery of research results. Each determinant of flood-prone areas includes a land slope, altitude, soil texture, drainage, land cover, and rainfall, analyzed spatially utilizing a map. Furthermore, based on the map, the regions are described based on the values that have been divided into classes. The results showed that the level of flood vulnerability in the Woyla watershed was divided into five classes, namely; the non-vulnerable class with an area of 14.88 Ha / 0.01%, low prone with an area of 90,731.62 Ha / 35.45%, medium with an area of 57,120.35 Ha / 22.32%, high with an area of 44,918.15 Ha / 17.55%, and very high with an area of 63,151.72 Ha / 24.67%. Also obtained a map of the distribution of flood hazard areas, the Woyla watershed area is divided into five classes, namely; the very light class with an area of 179,146.15 Ha / 70.00%, mild with an area of 32,868.84 Ha / 12.84%, moderate with an area of 20,129.93 Ha / 7.87%, danger with an area of 6.007. 29 Ha / 2, 35%, and very dangerous with an area of 17,784.51 Ha / 6.95%. The level of flood vulnerability in the Woyla watershed is dominant in West Aceh Regency, which is in the very high and high category classes with a total area of 56,876.65 Ha and 23,527.40 Ha. Meanwhile, the level of flood hazard in the Woyla watershed is also more dominant in West Aceh Regency than falls into the most dangerous and dangerous class category with a total area of 17,784.51 Ha and 6,007.29 Ha. With the largest part in the very light class at the flood hazard level of 179,146.15 ha.

Playa wetlands are widely distributed across the High Plains of the central United States, providing a range of ecosystem services, such as groundwater recharge, surface water storage, and wetland habitat. Although playas are essential resources, few studies have examined the variability and controls on playa water storage. The purpose of this project is to determine how playa and watershed morphology, watershed land cover, and precipitation patterns affect timing and duration of water storage in playas. This project focuses on 92 playas distributed throughout a 10-county region in western Kansas. Playa and watershed morphology were calculated in a GIS environment and classified into quartiles based on playa and watershed surface area. Watershed tilled index (i.e., percent cropland versus grassland) was determined using 2016, 2017, 2018, and 2019 Cropland Data Layers available from the National Agricultural Statistics Service and classified as either cropland (more than 75% cropland), grassland (more than 75% grassland), or mixed. Monthly precipitation data for 2016–2019 were compiled from the Oakley 22S High Plains Regional Climate Center weather station. Playa water status for 2016–2019 was classified monthly as either standing water or dry (i.e., no visible standing water) by visually examining four-band satellite imagery with 3.7 m resolution available from Planet Explorer (www.planet.com). Playa water status is influenced by a combination of factors, including playa and watershed morphology, watershed land cover, and precipitation patterns. Larger playas have larger watersheds and standing water more frequently and for longer periods than smaller playas. Playas in cropland watersheds store water more frequently and for longer periods than playas in grassland watersheds, though differences are not statistically significant. Standing water within playas is positively correlated with monthly precipitation and reflects a short-term response to precipitation patterns, regardless of playa size or watershed land cover. The strongest controls on playa water status are playa area, monthly precipitation, and watershed area. Playas are critical resources for the High Plains, providing a range of ecosystem services that are dependent upon the playa’s ability to store water. Playa functions are under continued threat from cropland expansion, climate change, and playa and watershed modifications. To sustain playa functions in Kansas, efforts should focus on conserving larger grassland playas and reducing sediment inputs to playas in cropland watersheds.

Anggomate River has ecological and economic value for the local community. Massive community activities in utilizing land in the Anggomate watershed area for plantation, inhabitation, and sand mining lands can cause the tree vegetation decline, even flood often occurs in Andowia region annually. The research method used was a quantitative method. Sampling was performed through a plot-transect method. The plots were placed on the downstream (Labungga Village river area), middle (Laronaga Village river area), and upstream (Andowia Village river area) regions. The study results showed that there are 35 tree species with the individual number of 64. The highest importance value index was obtained from Ficus benjamina L. at 29.38%, Anthocephalus cadamba (Roxb.) Miq) at 25.64%, and Lansium domesticum Corr. at 16.81%. The dominance index of the tree species in the Anggomate river area was 0.971, which indicates that one of the tree species dominated this area, namely, Anthocephalus cadamba (Roxb.) Miq) (Roxb.) Miq). The diversity index in the Anggomate watershed area includes in high category (H’= 3.402 atau H’ > 3). The distribution index includes in the evenly distribution category due to obtaining closely approaching the value of 1 (E= 0.818).

In the present study, the groundwater potential zone was demarcated and suitable site selection for the water storage structures was identified in the Deoria watershed of Jharkhand by using analytical hierarchy process. Thematic layers of lithology, geomorphology, soil, lineament, lineament density, slope, relief, aspects, drainage, drainage density, land use and land cover, and groundwater depth maps were created. The watershed falls under fourth-order river basin. A major portion of the basin is mainly dominated by lower order streams. Groundwater potential zones were categorized as very good, good, moderate, bad, and very bad. Only 9.37% of the total watershed area falls under a very good category. Twenty-eight suitable sites were recognized for constructing water harvesting structure in the Deoria watershed. The vast majority of the Deoria watersheds were observed to be appropriate for check dam. The watershed is characterized as having a reasonable land-use class (forest, river bed), slope (under 15%) and soil type (sandy loamy topsoil) which fills the need for soil and water conservation and groundwater expansion. The appropriateness of other water storage structures like nala bandh, farm pond and bore well were apportioned on the grounds. Remote sensing, satellite data, and GIS techniques provide a convenient approach for delineating the potential of groundwater zones which ultimately support the better planning and management of groundwater resources.

Land degradation resulting from soil erosion is a major problem in rain-fed agricultural areas in India. This study analyses the key determinants of farmers’ decisions to adopt on-farm soil and water conservation (SWC) measures in the rain-fed watershed areas of Siddipet district in Telangana. Here, SWC measures have been undertaken by the government and NGOs at the sub-watershed/community level and by individual farmers at the farm level. The study is based on a primary survey of over 400 farmers conducted in January–March 2018. In addition to estimating the influence of biophysical and market access variables on farmers’ decisions to undertake SWC practices, the study includes a logistic model that found a complementarity between community and individual plot-level interventions to improve soil health. The findings also highlight the influence of conservation measures practised in the neighbourhood on farmers’ decisions to implement SWC measures.

Geographical information system and remote sensing are proven to be an efficient tool for locating water harvesting and recharge structures, groundwater potential, runoff, watershed prioritization through morphometric analysis. The management and conservation of watershed require scientific evaluation so that appropriate strategies can be implemented by the policymakers and stakeholders. This study evaluates the Parvati River Basin for prioritization of sub-watershed. We use analytical hierarchical approach with pairwise comparison matrix for ranking the parameters which has been derived through morphometric analysis of the watersheds. The linear (stream order, stream length, mean, stream length, stream length ratio, bifurcation ratio, rho coefficient), relief (basin relief, relief ratio, ruggedness number) and areal morphometric parameters (drainage density, stream frequency, texture ratio, form factor, circulatory ratio, elongation ratio, length of overland flow, constant channel maintenance) have been used for prioritization of watershed in the Basin. The results revealed that the basin comprises of complex topography with mountainous and hilly relief structures which results into high run-off. The prioritization of sub-watershed suggests that the largest watershed comprising of 36.09% total watershed area falls into medium category for water potential. The total area under very high to high category is 5.36% and 8.44% respectively. The relationship between morphometric parameter and watershed prioritization shows that the sub-watersheds SW1 and SW8 falls under very high to high category having high water holding capacity.

Water is an important resource of the earth’s surface and it is integral for all on this planet. The availability or the scarcity of water depends on the watershed characterizes that consider the basic, linear, and shape parameters of any waterbody. The objective of the study was to delineate 14 morphometric parameters in the Barind region (Dinajpur district, Bangladesh) for sustainable hydrological modeling. An ASTER-DEM of 30-meter resolution data, geographical information system (GIS), and Remote sensing technique were used for extracting drainage components of interest region. The whole study region was covered by the flow of the Purnovoba river, Jamuna river, Atrai river (part-1 and part-2). Research results found that the Purnovoba river had a high bifurcation ratio (0.9982) that defined hydrologically more disturbed than the other three watershed areas and it had a high stream frequency (0.8332) that denoted rocky having low infiltration capacity. Jamuna river had a low drainage density (0.7322) that defined more vegetation having higher permeability. Besides, the Jamuna river had the lowest no. of stream order that was insignificant in the steady runoff process and less prone to cause a flash flood. The research predicted that the availability of groundwater might decrease to Jamuna river in the future as it had the lowest basin area (217.42 sqr. km ) and perimeter (114.90 km) and the basin surface slope would become gentle to Atrai river part-1 for the lowest length of overland flow (0.6072). Purnovoba river experienced the lowest form factor (0.2351) which indicated the most possibility for erosion. The elongated ratio of all basins was greater than 0.5 which considered all the shapes were more elongated. These findings will help for further modeling of an integrated watershed for sustainable hydrological models in the Barind region.

Understanding how spatial pattern changes with scale can provide insights into its relationship with ecological processes. In riverine landscapes, spatial pattern could scale differently from other well-studied landscapes because of their dendritic form. The objectives of this study were (1) to assess how spatial pattern of hydrogeomorphic habitat patches (HGP) change with spatial extent, grain size, and thematic resolution, and (2) to quantify how spatial pattern in river networks varies across the contiguous United States (CONUS). We identified hydrogeomorphic patches in river networks located in different ecoclimatic domains. We then quantified spatial pattern within each river network using a suite of landscape metrics and investigated scaling relationships for each component of scale. We also assessed whether watershed area, river network length, and drainage density were related to spatial pattern among river networks and explored regional differences in the hydrologic, geomorphologic, and climatic variables that differentiate HGP types. When predictable, scaling relationships within river networks followed either linear, logarithmic, or power functions. Among river networks, spatial pattern was related to total network length, catchment area and drainage density. Rarely were HGP types in different networks characterized by the same suite of hydrologic, geomorphologic and climatic variables. In riverine landscapes, there are a variety of relationships between spatial pattern and scale. The scaling functions we present can provide a concise description of scale dependency in these landscapes and improve our ability to synthesize information across scales.

The Benanain Watershed is located in East Nusa Tenggara with an area of 3,181 km2 and is divided into 29 sub-watersheds. The East Nusa Tenggara itself is an eastern region of Indonesia with a unique climate condition called semi-arid. The high rainfall intensity occurring in short duration results in large surface runoff and erosion. Floods and erosion in semi-arid areas due to sensitive soils to drought and heavy rainfall extremely. This paper presents the application of the Soil Conservation Services-Curve Number (SCS-CN) real-flood flows through a digital map of soil type, land use, topography, and the heterogeneity of physical condition, especially for ungauged watersheds. The method used is an approach empirical to estimate runoff from the relationship between rainfall, land use, and soil hydrology groups. This watershed has a large area that must analyze every sub-watershed. The land-use of the Benanain watershed is secondary dryland forest by 44.26% and the hydrological soil group on the B group classification with medium to high absorption potential by 46.502% from the total area. The curve number value of the Benanain Watershed ranges from 56.54 to 73.90, where the mean CN value of 65.32. The rainfall (mm) for the 29 sub-watersheds in the Benanain Watershed has decreased by about 74.65% when being surface runoff or only 25.35% of water becomes surface runoff. The relationship between rainfall depth and CN is classified as standard response and trend line (flat slope) equilibrium occurs when rainfall depth value of 56.71 mm and CN is close to 66.30. The high variability of intense rainfall between the rainy season and the dry season had a significant influence on the curve number value in a large watershed area. Further analysis will be more accurate if it is supported by long rainfall data and observation runoff data as a control. Doi: 10.28991/cej-2021-03091711 Full Text: PDF

The suspension flow from the upper part of a volcano watershed, which has a very thick soil condition, is sensitive to landuse form. Agroforestry is the dominant landuse form in the volcanic landscape of Indonesia. There is a lack of detailed studies about suspension flow in the upper watershed where agroforestry is the land cover. This research, performed in agroforestry area, covered the correspondence between flow discharge and suspension flow discharge, the time lag of initial rain events and the formation of suspension flow; and the characteristics of the grain size of the suspensions during the flow. The suspension flow was measured at the outlet of a gully in key watershed areas, which yielded a total of 436 suspension data. The measurement analysis was conducted at every rain event in the field and in the laboratory. The crop characteristics in the rain catchment area were recorded in details during the field survey. The characteristics of the channels converging toward the gully system were observed during the field survey. There were three relationship patterns between the peak flow discharge and the peak suspension discharge, namely (1) the peak flow discharge corresponded to the peak suspension discharge, (2) the peak flow discharge preceded the peak suspension discharge, (3) the peak flow discharge occurred after the peak suspension discharge. The average time interval between the rain events and the occurrence of suspension flow was 17.7 minutes. The peak suspension content varied from 0.0016 g/L up to 4.71 g/L with an average of 1.03 g/L. The grain size of the suspension was dominated by 71-76% of clay fraction with an average of 73% at the rising phase and 68-71% of clay fraction with an average of 69% at the falling stage

Paddy is a staple food for most Indonesian people. A number of efforts were made to maintain the availability of paddy in the country. One of these efforts is to determine the beginning of the paddy planting season, especially lowland paddy in order to get maximum results and minimize crop failure. This study aims to determine the beginning of the growing season in the Limboto Bone Bolango watershed area. The beginning of the rainy season is the best time to be the beginning of the paddy planting season which requires sufficient irrigation in the vegetative phase. The data used in this study is rainfall time series data which is processed from TRMM 3B43 data: Monthly Precipitation Estimates (TRMM/3B43V7) and ERA5-Land monthly averaged - ECMWF climate reanalysis (ECMWF/ERA5_LAND/MONTHLY). Based on the time series data, the beginning of the rainy season is in February (DOY > 60) and October (DOY > 273). Based on this, it is expected that farmers in the Limboto Bone Bolango watershed can start the planting season in February and October.

This study aimed to assess land degradation sensitivity of an area contributing to desertification risk in Lam Ta Kong Watershed using Environmental Sensitivity Area Index (ESAI). Five risk factors comprised climatic, soil, geographical, land utilization and vegetation, and water resources factors together with fifteen sub-factors were used to analyze the sensitivity to land degradation. The spatial analysis was calculated using Geographic Information System (GIS) and Remote Sensing (RS) techniques. The key factors influencing land degradation risks in the watershed area were analyzed using the triangular fuzzy numbers (TFNs) method. The results showed that approximately 33% of Lam Ta Kong watershed was affected by a high desertification risk excluded the water bodies and around 24.64% of the area suffered from a moderate risk. This research pointed out that key factors causing land degradation and desertification in the watershed area were related to the soil factors, followed by climatic, geographical factors, water resources, and land utilization and vegetation, respectively. The results of this study can be used as a database for planning and implementing area-based mitigations and measures as well as for land use planning in the watershed area.

This research integrated easy-to-handle remote sensing data and geoinformatics techniques for erosion mapping and groundwater management in the River Amba watershed, central Nigeria. It is aimed at: (a) the determination of the erosion-prone areas and (b) the estimation of the groundwater potential contamination risk under current and future anthropogenic activities. Rainfall intensity was evaluated from monthly rainfall data (2001 - 2011) from the station located within the River Amba Watershed. Digital Elevation Model (DEM) for the terrain was created using the 3D Analyst tool (Surfer 14) and was used to determine the flow direction and lineament features in each raster cells. Remote sensing data (aerial photographs and LANDSAT imagery) were used to develop a land-use map, while geological mapping was used to determine the local geology of the watershed area. The contributions of the various factors to the erosion hazardous areas are: elevation 31.49 %, land use 21 %, slope 14 %, geology 12.52 %, rainfall intensity 10.5 % and flow accumulation 10.5 %. The combined influences of these factors to erosion susceptibility as either: very high, high, moderate, low, and very low with the south-western part characterized as high while other parts of the study area moderate to very low erosion vulnerability. The groundwater level is shallow (4.0 –28.5 m) and discharges through the Amba river and many springs. These springs along with boreholes and wells supply drinking water to Lafia and the environs.

The population in urban areas continues to increase while the land owned is limited which results in slum settlements in urban areas. Slum settlements in Medan City often appear in areas where buildings should not be allowed, such as in watersheds. Deli River as a large river that divides Medan City, there are still many slum settlements in the watershed. Management of slum settlements based on sustainable development is needed to provide a long-term impact, especially for the preservation and restoration of the function of the Deli River. This study aims to analyze the management of slum settlements based on sustainable development indicators in achieving sustainable development, namely ecological sustainability, economic sustainability, socio-cultural sustainability, political sustainability, and defense and security sustainability. The research method used is descriptive qualitative. Sources of research data by collecting primary data through interviews and secondary data through documentation and observation studies. The management of slum settlements based on sustainable development in the Deli watershed is still not optimal in terms of ecological sustainability, economic sustainability, and defense and security sustainability. Meanwhile, socio-cultural sustainability and political sustainability are quite optimal. The government must manage slum settlements based on sustainable development through an approach with the community and provide viable housing alternatives so that people do not live in watershed areas.

Recently, land-use change, as well as climate change through seasonal floods, have caused increasing damage to the Hajji Qushan watershed. Therefore, to reduce the peak discharge of floods, the construction of earth dams is necessary and inevitable. This study aimed to evaluate the effect of embankment structures on the reduction of peak discharge and their effects on the downstream flow regime. For this purpose, to present a favorite rainfall-runoff model and to route the mainstream channel, the HEC–HMS model was utilized. The required data included data from three rain gauge stations and two hydrometric stations. To delineate the boundaries of the watershed, ArcGIS 10.3 (HEC–GeoHMS extension) was implemented. To extract the digital elevation model (DEM), 10-m contour lines were used. The results showed the lack of satisfactory effects of dam construction on the reduction of peak flood discharge. The location of dam construction, reservoir capacity, and watershed area were of the factors that determined the possible reduction of flood risk.

Tambakbayan is one of the watersheds in Yogyakarta, Indonesia that is experiencing changes in land use. The research aims to analyze the distribution of intrinsic and specific groundwater vulnerability in the watershed that was influenced by land-use changes from 2006 to 2017. The data used are the RBI maps (containinh topographic and land-use information, 2006 and 2017), SRTM imagery, rainfall recorded at the Kambil, Prumpung, Bronggang, Santan, Gemawang, and Karang Ploso stations (2006-2017), soil map, and aquifer map. Land-use change was analyzed by comparing the RBI maps of 2006 and 2017; while the groundwater vulnerability was assessed with the Susceptibility Index a development of the DRASTIC method. The intrinsic groundwater vulnerability was generated based on physical conditions, including depth to the water table, aquifer media, groundwater recharge, and topography, while the specific groundwater vulnerability was a function of these attributes added with one anthropogenic parameter : land-use. Then, all of these parameters were analyzed with map ovelay. The results showed two levels of intrinsic vulnerability : low (2.18% of the watershed area) and medium (97.8%); and three classes of specific vulnerability : low (0.02%), medium (5.06%), and high (94.92%)in 2006. From 2006 through 2017, the areal percentage of the medium vulnerability increased, while that of the high vulnerability decreased due to the conversion of agricultural land to a reservoir in 2009.

In this paper, we focus on the assessment of land-use and land-cover change detection mapping to the effective planning and management policies of environment, land-use policy and hydrological system in the study area. In this study the soil and water conservation project has been applied during the five years and after five years what changes have been found in the land-use and land-cover classes and vegetation. In this view, this land-use and land-cover mapping is a more important role to decide the policy for watershed planning and management project in the semiarid region. In an emerging countries, fast industrialization and urbanization impose a significant threat to the natural atmosphere. The remote sensing and GIS techniques are crucial roles in the study of land-use and land-cover mapping during the years of 2007, 2014, and 2017. The main objective of this is to prepare the land-use and NDVI maps in the years of 2008, 2014 and 2017; these maps have prepared from satellite data using the supervised classification method. A normalized difference vegetation index map (NDVI) was done by using Landsat 8 and LISS-III satellite data. NDVI values play a major role in monitoring the vegetation and variation in land-use and land-cover classes. In these maps, four types of land are divided into four classes as agriculture, built-up, wasteland, and water body. The results of study show that agriculture land of 18.71% (158.24 Ha), built-up land of 0.62% (5.31 Ha), wasteland of 40.33% (341.02 Ha), and water body land of 17.39% (147 Ha) are increased. Land-use and land-cover maps and NDVI values show that agriculture land of 22.97% (194.29 Ha), 5.46% (14.59 Ha), and 0.08% (0.22 Ha) decreases during the years of 2008, 2014, and 2017. The results directly indicate that the supervised classification method has been the accurate identified feature in the land-use map classes. This classification method has been given the better accuracy (95%) from spatiotemporal satellite data. The accuracy was also tally with ground-truth and Google earth information. These results can be a very useful for the land-use policy, watershed planning, and management with natural resources, animals, and ecological systems.

Due to the intensive human activities and rapid economic development during the past few decades, the anthropogenic sourced nitrogen (N) input into coastal waters has increased dramatically. In this study, the net anthropogenic nitrogen input (NANI), including the deposition of atmospheric N, the application of N fertiliser, the fixation of biological N, and the net N inputs from food and feed, into the Zhanjiang Bay watershed from 1978 to 2018 were estimated using statistical data, and the driving forces were analysed using the Logarithmic Mean Divisia Index (LMDI) factor decomposition approach. The results show that the NANI dramatically increased from 5269 to 20 639 kg N km−2. The cause of this increase was related to high input from N fertilisers and the net food and feed N input (with average contributions of 56.45% and 41.42%, respectively), which was accompanied by rapid economic development in Zhanjiang Bay. The output from the LMDI illustrates that the cause of the changes in the NANI was a shift in the dietary structure instead of an increase in the human population, which suggests that the impact of human population on the increase in the NANI using simple relational analysis may be overestimated. Remarkably, we found that the N from aquatic protein and animal protein comprised a significant proportion of the total N consumption in this coastal city, which differs from previous studies of inland cities. This is likely due to the fact that aquaculture is significantly developed in this coastal city.

In environmental management, land cover change is a crucial aspect. The area of tropical savanna environments is vulnerable to land degradation. This study aimed to rapidly detect land cover changes in a tropical savanna environment based on remote sensing data. Conditional change detection was performed using the Change Vector Analysis (CVA) with input parameters such as the Enhanced Vegetation Index (EVI) and Normalized Difference Soil Index (NDSI). The results showed that during the period 2015 to 2019, changes were detected in the Moyo watershed every year. From 2015 to 2016, the Moyo River Basin was dominated by changes with a change magnitude of less than 0.088, which was 63% of the Moyo River Basin area. From 2016 to 2017, the changes were dominated by the change magnitude value of 0.063, which was 58.6% of the Moyo River Basin area. From 2017 to 2018, changes were dominated by the change magnitude value of 0.084 of 55.26% of the Moyo watershed area. From 2018 to 2019, the change was dominated by the change magnitude value of 0.057, which was 47.57% of the Moyo watershed area. The direction of land cover change was dominated by Q2 in 2016, Q4 in 2017 and 2018, and Q2 and Q4 in 2019. These changes generally occurred in the Moyo watershed middle and downstream parts, which are grasslands. The use of the Conditional Change Vector Analysis (CCVA) approach in a tropical savanna environment can detect changes and the direction of change with an accuracy of about 70%.

The analysis of the watershed gives the surface area of land that rain streamed arrived in the river. The modern method to analyze the catchment is the ArcGIS program based on the Digital Elevation Model (DEM). The study area is An Najaf province, which area equaled about 27675 square kilometers. The HECGeoHMS (Hydrologic Engineering Center's Hydrologic Modeling System) is the link program on the ArcMap software that abled by serious steps to analyze the specific watershed. The auto analysis of the watershed area gives four basins for each outlet points located on the distributary Euphrates river. These four basins consisted of multi sub-basins and streams of rain flow. Basin 4 has the most significant volume, about 11.4% of the total case area of the basin, and the average slope is 3.2%. According to the amount of accumulative rainwater, basin 4 is essential when any obstruction is constructed at the end of the outlet point in the stream. This location of the construct is used to prevent the sediment in the Euphrates river and to avoid surface soil degradation. The arrangement of importance basin based on the advantage of water using to give maximum discharge and low evaporation is basin four at the first, basin two at the second.

The slope length gradient (LS) factor expresses the effect of topography, i.e., combining effects of slope length (L) and slope steepness (S) on rate of soil erosion. The longer the slope length, greater is the amount of cumulative runoff and similarly steeper the slope of the land the higher is the velocities of the runoff that contributes erosion. The LS factor is the most important parameter for estimation of soil loss and soil management using Universal Soil Loss Equation (USLE) and Revised Universal Soil Loss Equation (RUSLE). A precise inventory and assessment of vulnerable areas includes the formulation of correct soil management for property development. Juri is a peri-urban watershed situated in Tripura, India, having high undulating topography, which leads to increase soil erosion and land slide problem. Therefore, it has become essential to quantify the LS factor to understand the characteristics of the topographic factor, which will help the researchers for estimation of soil erosion and preparation of management plan. The present study focused to evaluate the LS factor for the sub-watershed areas of Juri River of Tripura. Two methods namely (1) suggested by Moore and Burch (1986) and (2) proposed by Wischmeier and Smith (1978) were used to calculate the LS factor. Both the methods use Digital Elevation Model (DEM) in spatial domain to estimate the LS factor. The LS factor of the study area ranges from 0 to 982.71 by method-1 and 0.66 to 285.58 by method-2. The study indicates that, the method-2 is more apposite than method-1 because it gives LS factor value, which distributed uniformly in spatial domain; whereas method-1 resulted highest LS factor value along the flow direction and it had almost same value of LS factor in the remaining areas. This study will help for prediction of soil erosion and preparation of management plan by reducing the slope length of the study area. This findings and the methodology employed can be widely used in similar mountainous to hilly watersheds around the world for calculation of soil loss.

We surveyed herpetofauna along the poorly-explored region of two watersheds of Kumoan Himalaya, Dabka and Khulgarh. Adaptive cluster method was used to collect forest floor reptiles, and stream transect was used for stream reptiles and amphibians. In total, 18 species of reptiles were recorded in two watersheds, with 15 and nine species recorded in Dabka and Khulgarh, respectively. Forest floor density of reptiles was 87.5/ha in Dabka and 77.7/ha in Khulgarh. In terms of species, Asymblepharus ladacensis and Lygosoma punctatus density were highest in Dabka and Khulgarh, respectively. Eight species of amphibians were recorded in Dabka with a density of 9.4/ha and four species in Khulgarh with density of 5.2/ha. In both watersheds, density of Euphlyctis cyanophlyctis was highest. Reptilian and amphibian diversity of Dabka was 1.52 and 1.23, respectively, and in Khulgarh 0.43 and 0.23, respectively. In both watersheds reptile density, diversity and richness decreased with increasing elevation. Reptile density showed a weak correlation with microhabitat features such as litter cover, litter depth, and soil moisture in both watersheds. Amphibian density was positively correlated with soil moisture, litter cover, and litter depth. Comparison showed that Dabka is richer and more diverse than Khulgarh, presumably because of the undisturbed habitat, broad and slow stream, and deeper forest litter of the former.

Daihai Lake (DL), the third largest inland lake in Inner Mongolia, has shrunk severely given the conditions of no significant decrease in annual precipitation. On the basis of field surveys and Landsat remote sensing images, this study analyzed land use and land cover (LULC) changes in six periods of the DL watershed area during 1986–2019. Then, with the combination of the LULC results and the Soil Conservation Service–Curve Number method, we discussed the change characteristics and influence factors of the surface runoff in the watershed and the reason for DL shrinkage. From 1986 to 2019, the water area of DL decreased rapidly at a rate of −2.22 km2/year, and the area of farmland and grassland in the watershed changed strongly along the opposite trend. The surface runoff in the DL watershed was reduced by approximately 513.6 million m3 during the last 34 years. In addition to local rainfall, groundwater is also an important water supply to the lake and accounts for a greater proportion. The average recharge rate of groundwater to the lake is approximately 64.55 million m3 per year in the past 34 years. The area change of the DL is related to the runoff reduction, huge evaporation, and lake water use in thermoelectric power generation. The local precipitation cannot enter the groundwater in DLW. Large-scale exploitation of external groundwater for agricultural irrigation and industrial production is another important cause of lake degradation.

A sense of concern for the environment, one of which is by planting tree seeds. On this community service activities this time, we planted tree seedlings in the Citarum Watershed (DAS), in Jelegong village, West Bandung. The location selection was based on the condition of the area which was damaged by human activities, including the conversion of land into a trash can. This tree planting activity has a negative impact on the surrounding environment. This activity was carried out before the pandemic, on November 24-25, 2019 involving the Budi Luhur University Academic Community as a form of concern for the environment. This activity also involves Jelegong Village Community and Officials as well as the TNI who served as the Sector 8 task force. The tree seedlings planted were fruit tree species such as mango, rambutan, jackfruit and others.The number of trees that planted spread across the watershed totaling 150 trees. The one, who is responsibility for the maintenance of this plant is a shared responsibility between the Budi Luhur University Community, this activity is expected to increase the awareness of the people of Jelegong Village about the importance of maintaining and conserving the balance of nature, especially in the watershed area in Jelegong Village.

Rainfall and run-off prediction capabilities for flash flood need improvement in the high porn regions of mountain hazard, those caused massive distraction. At some point, these events result in a massive loss of life and property. This research demonstrates the application of soil conservation service (SCS), a hydrological model used to simulate the relationship between rainfall and run-off. The data cover a 62-year observation period of torrential rains and debris flows, which number up to thirty flow events, all occurring in the mountainous regions close to the Tieli watershed area. Rainfall hydrographs were generated for each of the said torrential rain cases and can be used as markers for flood warnings for critical rainfalls lasting from 1 to 24 h. The results show that the SCS model can successfully define the rainfall–run-off-water level relationship of small-medium-size catchments wherein the calculated run-off values show good agreement with measured discharges. Moreover, from the relationship of the water level and SCS calculated run-off is similar to the relationship obtained using measured run-offs. From this relationship, critical water levels that would correspond to the occurrence of a possibly devastating flood can be determined to provide for an early warning measure for the nearby regions.

Rapid socio-economic development has led to a significant deterioration in the water environment, which has limited sustainable regional development. The soil and water assessment tool (SWAT) and statistical regression method were used to model the ammonia nitrogen (NH4+-N) pollution and explore the impacts of land use and socio-economic factors on NH4+-N pollution within the Weihe River watershed in China from 2015 to 2018. The result of SWAT model revealed that the NH4+-N concentrations were usually relatively high under low runoff conditions and relatively low under high runoff conditions. The average NH4+-N concentration in the upper reaches was 0.77 mg/L, whereas it was 0.87 mg/L in the middle and lower reaches of the watershed. Serious NH4+-N pollution mainly occurred in 2015 and 2016, and the V (2.0 mg/L) and V+ (>2.0 mg/L) water quality classes were associated with approximately 6.67% and 28.94% of the total watershed area, respectively. The multiple linear regression indicated that the building land and secondary industry were the significant controlling factors (P < 0.01). According to the scenario analysis, modelled scenarios for interception measures reduced the NH4+-N load to a greater degree than scenarios for source control measures. To improve the surface water quality in the Weihe River, it is recommended to adjust industrial structure, increase sewage treatment, and strengthen the rural management of the watershed.

Observations and modeling are used to assess potential impacts of sediment releases due to dam removals on the Hudson River estuary. Watershed sediment loads are calculated based on sediment-discharge rating curves for gauges covering 80% of the watershed area. The annual average sediment load to the estuary is 1.2 Mt, of which about 0.6 Mt comes from side tributaries. Sediment yield varies inversely with watershed area, with regional trends that are consistent with substrate erodibility. Geophysical and sedimentological surveys in seven subwatersheds of the Lower Hudson were conducted to estimate the mass and composition of sediment trapped behind dams. Impoundments were classified as (1) active sediment traps, (2) run-of-river sites not actively trapping sediment, and (3) dammed natural lakes and spring-fed ponds. Based on this categorization and impoundment attributes from a dam inventory database, the total mass of impounded sediment in the Lower Hudson watershed is estimated as 4.9 ± 1.9 Mt. This represents about 4 years of annual watershed supply, which is small compared with some individual dam removals and is not practically available given current dam removal rates. More than half of dams impound drainage areas less than 1 km2, and play little role in downstream sediment supply. In modeling of a simulated dam removal, suspended sediment in the estuary increases modestly near the source during discharge events, but otherwise effects on suspended sediment are minimal. Fine-grained sediment deposits broadly along the estuary and coarser sediment deposits near the source, with transport distance inversely related to settling velocity.