Change-point detection and variation assessment of the hydrologic regime of the Wenyu River

Abstract

ABSTRACTIn recent decades, remarkable hydrological variations resulting from climate change and human activities have significantly affected rivers globally. Thus, it is important for local water resource planning and management to examine hydrologic regime variations. The aim of this study was to determine the changes in the mean annual runoff series and hydrological characteristic parameter of the Wenyu River. In addition, climate change and human activity were discussed for looking for the most causative factors of hydrological variations of the Wenyu River. The results indicated that annual runoff series exhibited an overall decreasing trend with two significant change points in 1972 and 1984. Over time, the number of hydrological variation index increased significantly and different changes of hydrological regime were exhibited during various periods. The comparative analysis indicated that the variations in runoff were likely driven by human activity rather than climate change. Reservoir operations and changes in water consumption resulting from regional economic development in human activities markedly affected the hydrological features of the Wenyu River. To be specific, the variations in annual runoff and low flow were attributed to regional fluctuations in water demand, but the inter-annual changes and maximal and minimal flow variations after 1972 were likely due to the joint influence of reservoir regulations and variations in water consumption.