大型水资源配置工程堆积体坡面植被覆盖度对氮磷流失的影响OA

[Objective]This study aims to explore the correlations between runoff volume,concentrations and loss rates of TN and TP under varying vegetation coverage levels,so as to address the nitrogen and phosphorus loss issue on slopes of engineering deposit pertaining to large-scale water resources allocation projects.[Methods]Taking the engineering deposit of the Yijia Courtyard large-scale water resources allocation project in Yongchuan,Chongqing as the research object,this study conducted field artificial water scouring experiments on slopes with three vegetation coverage levels:low(4%),medium(12%),and high(50%)through field investigations,and investigated the characteristics of nitrogen and phosphorus loss under different vegetation coverage on the slopes of engineering deposits in large-scale water resources allocation projects.[Results]Under low and high vegetation coverage,the runoff rate exhibited a fluctuating increasing trend with the scouring duration,while under medium vegetation coverage,it showed a fluctuating trend of first decreasing and then increasing.There was no significant difference in the average runoff rate among the three vegetation coverage levels(p>0.05).The average concentrations and average loss rates of total nitrogen(TN)and total phosphorus(TP)all showed a trend of first increasing and then decreasing with the increase in vegetation coverage.Under the three vegetation coverage levels,the concentrations and loss rates of TN and TP presented a fluctuating decreasing trend with the scouring duration.The average concentrations and average loss rates of TN and TP under medium coverage were significantly higher than those under low and high coverage(p<0.05),with increases of 56.38%,60.21%and 57.62%,54.50%,respectively.The nitrogen and phosphorus loss rates were mainly driven by concentration.[Conclusion]Under different vegetation coverage levels,the runoff rate exhibits a fluctuating increasing trend;the nitrogen and phosphorus loss rate is the highest under medium vegetation coverage,while low and high vegetation coverage can effectively reduce the nitrogen and phosphorus loss rate on engineering deposit slopes.