The present study highlights the importance of Digital Elevation Model (DEM) and satellite images for assessment of drainage and extraction of their relative parameters for the Orr watershed Ashok Nagar district, M.P., India. Hydrological parameters such as drainage analysis, topographic parameters and land use pattern were evaluated and interpreted for watershed management of the area.Hydrological module of ARC GIS software was utilized for calculation and delineation of the watershed and morphometric analysis of the watershed using SRTM DEM. The stream order of watershed ranges from first to sixth order showing dendritic type drainage network which is a sign of the homogeneity in texture and lack of structural control of the watershed. The drainage density in the area has been found to be low to medium which indicates that the area possesses highly permeable soils and low relief. The bifurcation ratio varies from 4.74 to 5 and the elongation ratio is 0.58 which reveals that the basin belongs to the elongated shaped basin category. The mean Rb of the entire basin is 4.62 which indicates that the drainage pattern is not much influenced by geological structures. Land use map of the watershed was generated from latest available multispectral satellite data and whole watershed covers under agricultural land, settlement, fallow land, forest, mining areas and water body.The present study reveals that SRTM DEM based hydrological evaluation at watershed scale is more applied and precise compared to other available techniques
Glacial Lake Outburst Floods (GLOFs) in a deglaciating environment, representing significant threat to downstream people and infrastructure, increasing the necessity of prioritization and assessment of potentially critical glacial lakes (PCGLs). In this current study, a comprehensive updated inventory of glacial lakes for the Indus River basin has been prepared, resulting in 5,335 lakes (≥ 0.0025 ± 0.0006 km2), covering a total area of 173.95 ± 10.13 km2. Parameters have been derived using satellite data for two purposes, ‘preliminary screening’ and ‘quantitative assessment’. Using 4 parameters, 367 lakes were preliminary screened-in for further analysis, and 6 quantitative parameters were analysed using Equal Weights (EW) and Unequal Weights methods (UEW). These both methods were applied for two scenarios, scenario-1 which considers 73 lakes (≥ 0.1 km2), and scenario-2 which considers all 367 preliminary screened-in lakes (≥ 0.02 km2). UEW outperformed EW analysis and identified 20 and 48 high potential lakes for scenario-1 and scenario-2 respectively, where all 20 lakes of scenario-1 have been found in common with those of scenario-2, with a difference in their rank. But only 10 of them have storage volume ≥10 MCM and has been flagged as high-risk lakes, of which 6 are end-moraine dammed lakes and have been considered as PCGLs, due to their high bursting potential and self-destructive nature. Rest 4 high risk lakes along with remaining 38 lakes with volume <10 MCM, are considered as critical lakes in case of dynamic mode of failure, caused due to mass movement of avalanche, landslide, heavy precipitation, etc. Graphical Abstract