Multi-site hydrometeorological simulation of streamflow for upper Jhelum basin in northwest Himalayas using HEC-HMS soil moisture accounting algorithm

Hydrometeorological influence on run-off is a process-driven mechanism in basin hydrology that needs to be captured for a reliable assessment of the basin-scale hydrological responses in the context of climate change. In this study, one of such process-based model, the Hydrologic Engineering Center-Hydrologic Modeling System model is used to simulate multi-site streamflow in the upper Jhelum basin, northwest Himalayas, India. The soil moisture accounting algorithm was used to calibrate and validate the model for continuous simulation on a monthly timescale at three gauging stations Ram Munshi Bhag, Sangam, and Rambiara. The model was calibrated for a period of 12 years (2003-2014) and validated for 5 years (2015-2019). Observed and simulated streamflow values during the calibration period were found to be in good agreement with R-2 ranging from 0.783 to 0.808, NSE from 0.753 to 0.793, and P.B from 2.7 to 5.1%. Similar performance was obtained during the validation period also with R-2 ranging from 0.80 to 0.83, NSE from 0.70 to 0.80, and PB from 2 to 6.8%. The sensitivity analysis of the model was performed using one-at-a-time analysis method. This helps to rank the parameter according to their sensitivities towards the model performance in simulating run-off volume. Soil storage, soil tension storage, and soil percolation were found to be the most sensitive parameters while groundwater-2 coefficient storage, and percolation were the least sensitive parameters in the basin. The overall model performance was reasonably good, and can be further used for rainfall-run-off simulation in the upper Jhelum basin for the climate change impact related studies in future.