Quantification of Persistent Snow and Glacier melt Contribution in Hydrological Regime of Jhelum River basin using Spatial Processes in Hydrology (SPHY) model

Abstract

Economy of Pakistan is largely based on agriculture activities which are strongly connected with water resources and a step ahead hydrological behaviour of rivers catchment in northern region of Pakistan. Jhelum River is the most significant western tributary of mighty Indus River which receives significant amount of glacier and snow melt. For current study Spatial Processes in Hydrology (SPHY) model is used to quantify hydrological components (base flow, rain fall, snow and glacier melt runoff) along with focus on changes in runoff sources, seasonal change in hydrological components and hydrological extremes. Due to trans-boundary nature of Mangla catchment, bias corrected WFDEI climate data was used. SPHY model was calibrated using actual evapotranspiration and discharge data to simulate discharge data and its hydrological components. It has been observed that runoff is underestimated due to low values of precipitation data for high altitude areas. Overall, peak runoff for the catchment is observed during snow melt season. A true representation of hydrological components all over the year and seasonal changes in rainfall, glacier snow melt runoff are observed. Analysis of hydrological components reveals that snow melt runoff peak occurs during summer and rainfall runoff peak occur during monsoon along with glacier melt runoff. Due to increase in precipitation and temperature over the time period (2001-2009), rainfall runoff, glacier and snow melt runoff are also increased. This model could be used to analyse climate change impacts on water sources and would help to improve reservoir operation for better water resources management.