The Kaligandaki River Basin is highly influenced by monsoon rainfall and its complex topography, resulting in pronounced spatial and seasonal variations in water availability. Soil and Water Assessment Tool (SWAT) was applied, for simulating water balance components under data limited conditions. The model was calibrated and validated using observed discharge data from the Manglaghat and Kotagaon stations, employing the SUFI-2 algorithm. The model showed satisfactory performance, with NSE and R² values exceeding 0.7 and 0.5, respectively, at both monthly and daily time scales as hydrological model performance is acceptable for NSE and R 2 more than 0.5. The simulation effectively captured key hydrological processes, including evapotranspiration, surface runoff, lateral flow, and baseflow, and revealed significant spatial and seasonal variability across the basin. Results indicate that approximately 24% of total precipitation contributes to surface runoff, another 24% to lateral flow, 16% to groundwater recharge, and about 22% is lost through evapotranspiration. Surface and lateral flows were found to dominate in the mid-hill regions, while baseflow contributions were more prominent in the lowland plains. Overall, the findings provide valuable insights into the hydrological dynamics of the Kaligandaki River Basin and offer a strong scientific basis for improved water resource management and policy planning.
Prajapati et al. (Fri,) studied this question.