Trends Analysis of Stream Flow at Different Gauging Stations in Upper Jhelum River

Abstract

Analysis of stream flow trends plays a significant role in the flood forecasting and hydrologic drought assessment related investigations besides study of water resource management In this study, the long-term stream flow data recorded at different gauging stations in Upper Jhelum River (UJR) in Jammu and Kashmir (J &K) state basin were estimated using the Modified Mann-Kendall Test (MMKT)  and Sen’s Slope Estimator (SSE).Long term time series data of ten gauging stations used for trend analysis were annual maximum and monthly maximum stream flows for the years (1980-2016) for the months of occurrence of flood in UJRB. It was observed that six gauging stations out of the ten showed a significant decreasing trend in discharge and depth of flow in the UJRB at 0.05 probability level of significance. However the results of the monthly and seasonal maximum stream flow analysis showed that during spring season (March to May) about 90% of the gauging stations depicted downward trends in the summer season (Jun to Aug) all the gauging stations showed downward stream flow trends and approximately 60% of the gauging stations showed downward trends in the month of September (first month of autumn). This analysis resulted into quantification of flood magnitudes and its periodicity of occurrences to develop flood mitigation strategies. Nonetheless, such investigation of water flow in the river would also assist in regional hydrologic studies besides occurrence of flood and hydrologic droughts.