Abstract:
Land use changes have a big impact on a watershed's hydrologic and ecological processes. To assess the implications of possible land-use change on storm-runoff generation in the Jhelum Basin, event based rainfall-runoff model is used in the present study. One of the most difficult challenges for hydrologists is modelling a large river basin with spatially and temporally dynamic land cover, topography, seasonal flows, and rainfall distribution patterns in a data-scarce and transboundary context.
The HEC-HMS Model and the IFAS Model were calibrated on a high flood in 2010 and validated on an extremely high flood in 2014, both with acceptable performance indices and meeting the study's goal. To achieve high efficiency in this environment, calibration and validation were carried out separately at the tributaries of the River Jhelum by finer spatial discretization, and rainfall data sets were integrated with APHRODITE data (bias corrected) for data scarce and transboundary regions in the current study. As an efficient calibration approach to modelling, the calibrated parameters obtained from each tributary were then applied to the main River Jhelum. Because River Jhelum categories of much variability from each basin, this efficient regionalized calibration has the main advantage of identifying realistic parameters for each basin for effective flood prediction at any tributary of River Jhelum basin.
To successfully captured and reproduced the peaks for respective basins in flood modelling utilizing APHRODITE data, providing a credible rainfall dataset for flood modelling. The APHRODITE project develops state-of-art daily precipitation and daily mean temperature datasets with high resolution grids for Asia.
By comparing the HEC-HMS and IFAS Model results, The calibration and validation finding of IFAS and HEC HMS models indicates a high level of agreement with the measured flow (NSE =0.58, R2 =0.76 and NSE=0.77, R2=0.87) and (NSE =0.531, R2 =0.826 and NSE= 0.451, R2= 0.828) respectively. By comparing the global land cover version 2 (2008) and version 3 (2013), the calibration and validation findings of HEC HMS indicated a high level of agreement with the measured flow (NSE =0.531, R2 =0.826 and NSE= 0.451, R2= 0.828) and (NSE =0.537, R2 =0.813 and NSE=0.454, R2=0.828) respectively.
