Applying a statistical method to streamflow reduction caused by underground mining for coal in the Kuye River basin

Streamflow in the Kuye River basin has been sharply reduced by the effects of climate change and human activities.Since 1997,the intensification of coal mining has resulted in substantial reductions to streamflow alongside an ever-increasing demand for water.In this study,we present a derived statistical method,incorporating the Mann-Kendall and Pettitt method（MK-P） and the Soil and Water Assessment Tool（SWAT）,and apply it to estimating the streamflow reductions caused by underground mining for coal in the Kuye River basin.The results show that underground mining is an important cause of the streamflow reductions observed since1997,being responsible for reductions of 21.15 mm/yr（~56%of the total） during 1997-2009.The results of the SWAT simulation were assessed by several performance criteria：Nash-Suttcliffe Efficiency（Nse）,correlation coefficient（R~2）,relative error（RE）,P-factor and Pv-factor.The close match between the simulations and observed data supports the reasonability of our findings.We suggest that engineering strategies be adopted to limit streamflow loss into goafs via fractured zones in the coalfield.