Variability of Geomorphological Characteristics and the Altered Hydrological Regime of the Upper Indus Basin, Pakistan

The administration of watersheds holds significant relevance in the field of water resources engineering and management. The main objective of this research is to assess the geomorphological attributes of the Upper Indus Basin (UIB) in Pakistan, with a particular emphasis on its hydrological phenomena. The demarcation of the boundaries of the 21 sub-basins within the UIB was achieved by employing ArcGIS software. The findings indicate that the subbasins demonstrate a range of drainage patterns, varying from sub-dendritic to dendritic. This suggests that there is a consistent texture and absence of structural influence within the subbasins. The research identified a range of stream orders, extending from 3.76 to 365.73 km, indicating a diversity in bifurcation ratios that spans from 3.00 to 5.40. The findings of this investigation suggest the presence of geologic formations that offer favorable conditions. The total length of streams and the number of stream segments demonstrate an upward trend in first-order streams, whereas they decline as the stream order advances. The Drainage Density (DD) of all sub-watersheds has a variation ranging from 0.170 to 0.231 km-1, indicating the presence of regions characterized by materials with notable resistance and porosity. The observed low drainage intensity in these watersheds suggested that the capacity to remove surface runoff is insufficient, rendering them susceptible to the occurrence of flooding, gully erosion, and landslides. Greater infiltration capacity and less runoff are correlated with higher elongation ratios. The findings derived from our study are intended to provide a significant contribution to the development of asustainable water management strategy for the UIB in the upcoming years. The main focus of this work is to analyze the geomorphological characteristics of mountainous watersheds located in the UIB of Pakistan and assess their influence on hydrologic processes.