Analysis of runoff variation and driving factors in the Minjiang River Basin over the last 60 years. Issue 10 (26th September 2022) - Zhai, Hongjuan
Abstract: An absolute essential for effective water resource management and ecological restoration is knowing the temporal and spatial variation of runoff. The objective of this study was to determine the spatial and temporal changes in runoff at the main hydrological stations along the Minjiang River and the Dadu River between 1961 and 2016 using the non-parametric Mann-Kendall test and annual variation analysis. Canonical correspondence analysis and regression analysis were used to determine the contribution of anthropogenic disturbance, vegetation, and climatic conditions to runoff change. The runoff at each station of the Minjiang River showed a clear decreasing trend, whereas the decreasing trend of the Dadu River was not significant. Moreover, the discharge at the Shawan (SW) station upstream of the Dadu River and the Gaochang (GC) station downstream of the Minjiang River have changed significantly during the flood and non-flood seasons since 2000, while the discharge at other stations has not changed significantly. The average annual runoff in the non-flood season at SW and GC in 2011–2016 increased by approximately 26.21 and 36.47%, respectively, compared with 1961–2010. Anthropogenic disturbance, vegetation, and climatic conditions in the Minjiang River Basin accounted for 76.24, 13.62, and 10.14%, respectively, of the runoff change in the basin. Water consumption and total reservoir capacity were the specific factors most affecting runoff change in the basin, accounting for 15.10 and 13.94%, respectively, of the changes in runoff. The research can provide important support for the ecological restoration of Minjiang River Basin and Yangtze River Basin. HIGHLIGHTS: A mutation occurred around 2010, hereafter the annual average flow at the Gaochang station increased by approximately 36.47% in the non-flood season. A significant downward trend in runoff from 1960 to 2016 occured in Minjiang. Hydropower projects and water resources utilization may have contributed greatly to changes in runoff. Graphical Abstract