摘要
Abstract
Under the background of climate change,water quality safety has been a hot concern worldwide,and human activities have increased the uncertainty of water quality safety.In this study,taking the Minjiang River basin(MRB)as an example,the seasonal Mann-Kendall trend analysis and Sen's slope trend estimation were used to systematically analyze the characteristics of spatial and temporal changes of water quality in the MRB and the impact mechanism due to climate change and human activities(pollution prevention policies,PPPs).In this study,acidity(pH),permanganate index(CODMn),dissolved oxygen(DO),five-day biochemical oxygen demand(BOD5),ammonia nitrogen(NH3-N),total phosphorus(TP),and chemical oxygen demand(CODCr)were selected as water quality indicators in the MRB.The results showed that the water quality of MRB has been significantly improved during 2011-2020.The SMK test confirmed that pH had no obvious change trend,DO had an upward trend,and CODMn,BOD5,NH3-N,TP and CODCr had significant decreasing trends in the MRB.Based on the SMK results,Sen's slope evaluated the mean change intensity(△ Mean)of water quality parameters with trend changes:CODCr＞BOD5＞CODMn＞DO＞NH3-N＞TP.Here,CODMn,BOD5,NH3-N,TP and CODCr decreased by 0.16 mg/L,0.23 mg/L,0.06 mg/L,0.02 mg/L and 0.88 mg/L per year on average,respectively,while DO increased by 0.11 mg/L per year on average.Therefore,through the correlation analysis of climate change,PPPs and water quality changes,we revealed that climate change increases the heterogeneity of precipitation and thus affect the spatio-temporal variability of water quality changes,but PPPs(human activities)were still the main drivers of water quality changes in the MRB.This study provides data and methodological support for watershed pollution prevention and control,water quality safety and scientific decision-making.关键词
气候变化/污染防治政策/水质/岷江流域/趋势分析Key words
Climate change/pollution prevention policies/water quality/Mingjiang River basin/trend analysis分类
资源环境
