Variability and time series trend analysis of streamflow in response to climatic and anthropogenic factors over Narmada River basin, India

During the past few decades, major river basins across the world have encountered significant alteration in streamflow due to climatic and human induced changes. The present study explores the spatio-temporal trend, variability and abrupt change in streamflow and its association with driving forces (climatic and human) in Narmada River basin, India. For this, time-series data regarding different natural and anthropogenic parameters have been collected and analysed with the help of different trend [Mann–Kendall (M–K), simple linear regression, innovative trend analysis etc.] and change point detection tests. In addition, the contributions of climatic and human factors in changing streamflow have been assessed through double mass curve and auto regressive distributed lag model (ARDL). The results reveal a significant decline in annual and monsoon streamflow in main channel, whereas, its tributaries have demonstrated an upward trend in streamflow. The change point detection tests have revealed a substantial alteration in streamflow since 1994. Despite an increase in annual rainfall, streamflow has declined due to combined effects of installation of dams and barrages, and increased water consumption. The human activities contribute 107.97% in reducing streamflow, while changing climate has enforced a counteracting effect (− 7.97%). The long-run coefficients of ARDL have revealed that temperature, water withdrawal, population, urbanisation etc. have negative effect on streamflow. The results of this study may prove a valuable asset for policymakers in designing effective policies related to sustainable use and management of water resources in Narmada River basin.