The impact of mining-related human activities on runoff in northern Shaanxi, China

Abstract

Northern Shaanxi, a major coal base in China, is facing water scarcity, soil erosion, and ecological deterioration. We chose the Kuye and Tuwei Rivers as the study area, in which many underground mining bases have operated in these catchments since the late 1980s. The objective of this study was to quantify the anthropogenic impacts of runoff on the main rivers in the mining region. First, trend analysis and change-point detection were used to examine changes in the magnitude of annual runoff. Then, the contributions of precipitation changes and human activities to runoff changes were distinguished. Linear regression and comparative analysis were used to quantify the extents of human impacts on the runoff in two representative catchments. The results showed that the annual runoff in both catchments decreased significantly at the 99% confidence level during 1960-2016. The significant change in the runoff occurred in 1997 in the Kuye River (KYH) catchment because of coal mining, while it occurred in 1980 in the Tuwei River (TWH) catchment due to soil and water conservation measures. The contribution of human activities to the runoff change was estimated to account for 91% and 42% in the KYH catchment and TWH catchment, respectively, whereas climate change accounted for 9% and 58%, respectively. Moreover, by reconstructing the time series of runoff, we surmise that anthropogenic interventions lead to a decrease in the average annual runoff by 168-344 million m3 (in the KYH catchment) and 152 million m3 (in the TWH catchment), respectively, during the descending period (1997-2016).