HYDROLOGICAL MODELING AND WATERSHED ANALYSIS OF SWAT RIVER BASIN BY USING HBV LIGHT MODEL AND ARC GIS

Abstract

Climate change is a pivotal global phenomenon, particularly impactful in nations like Pakistan. This study delves into the myriad factors driving climate change, specifically focusing on its profound effects on economically vulnerable countries heavily reliant on natural resources for water. Utilizing historical climatic and discharge data from the Swat River, located within the Khyber Pakhtunkhwa province, the research employs temperature, precipitation, and discharge data to scrutinize changes in the KALAM basin at a regional level. Situated between 34° and 36° N latitude and 71° to 72° E longitude, the Swat River Basin relies heavily on glacier snowmelt. The HBV model and GIS techniques are harnessed to dissect climate variations within the KALAM Basin. GIS aids in mapping the study area and visualizing temperature fluctuations in the basin. The basic HBV rainfall-runoff model undergoes automatic calibration using a straightforward yet effective method, providing satisfactory results during the 1981-2000 calibration and 2001-2010 validation periods. Noteworthy findings include the HBV-light model's adeptness at simulating stream flow and snowmelt in the snow-fed basin. However, the study emphasizes the substantial impact of parameter set values on the model's performance, highlighting the challenge of selecting an ideal parameter configuration. Sensitivity tests underscore the significant influence of climate change, specifically temperature increases, on stream flow across yearly, seasonal, and snowmelt contributions. Employing geographic information systems (GIS) alongside a digital elevation model proves instrumental in managing and analyzing water resources, aiding in watershed delineation—a crucial step in hydrological modeling. GIS, particularly the Arc Hydro tool, is valuable for determining grid directions in catchment areas, drainage lines, and flow accumulation. The research underscores the need for comprehensive scientific exploration to address knowledge gaps and enhance understanding of the applications of the HBV light model in the context of climate variations, particularly concerning water resources.