陕西大理河流域枯水期土地利用结构对河流水质的影响  

Impact of Land Use Structure on River Water Quality During Dry Season in Dali River Basin of Shaanxi, China

作　　者：刘然 徐国策[1,2] 李占斌[1,2] 王斌[1,2] 徐怀宇[3] LIU Ran;XU Guo-ce;LI Zhan-bin;WANG Bin;XU Huai-yu(State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China,Xi'an University of Technology,Xi'an 710048,Shaanxi,China;School of Water Resources and Hydropower,Xi'an University of Technology,Xi'an 710048,Shaanxi,China;Northwest Engineering Corporation Limited,PowerChina,Xi'an 710065,Shaanxi,China)

机构地区：[1]西安理工大学西北旱区生态水利国家重点实验室,陕西西安710048 [2]西安理工大学水利水电学院,陕西西安710048 [3]中国电建集团西北勘测设计研究院有限公司,陕西西安710065

出　　处：《地球科学与环境学报》2022年第2期327-337,共11页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(52022081);榆林市科技计划项目(2019-144);清洁能源与生态水利工程研究中心项目(QNZX-2019-03)。

摘　　要：土地利用变化对自然和生态过程影响显著,也是径流水质的主要影响因素之一。基于陕西大理河流域2020年枯水期21个采样断面的径流采样测定,分析了大理河流域总氮(TN)、总磷(TP)、氨氮(NH_(3)-N)浓度以及溶解氧(DO)浓度的特征。利用内梅罗污染指数对大理河流域水质进行了评价,辨识了不同尺度缓冲区内土地利用结构对水质的影响。结果表明:4种水质参数中,总氮超标最为严重。流域内梅罗污染指数平均值为1.9,水体轻度污染;干流平均值为2.3,支流平均值为1.2,支流水质优于干流水质。在点缓冲区,建设用地对总氮的影响在200 m范围比100 m范围大;在河网缓冲区,草地对总磷的影响以及建设用地对氨氮浓度的影响在100 m范围比200 m范围大。在100 m范围,草地是截留污染物的主要土地利用类型;在200 m范围,林地是截留污染物的主要土地利用类型。耕地、建设用地在点缓冲区和河网缓冲区对总氮、总磷、氨氮浓度均起“源”的作用;林地在点缓冲区“汇”作用更显著;草地在河网缓冲区“汇”作用更显著。Land use change has a significant impact on natural and ecological processes,and it is also one of the main influencing factors of runoff water quality.Based on the runoff sampling and measurement of 21 sample sections in Dali river basin of Shaanxi during dry season in 2020,the characteristics of TN(total nitrogen),TP(total phosphorus),NH_(3)-N(ammonia nitrogen)concentration and DO(dissolved oxygen)concentration in Dali river basin were analyzed;Nemerow pollution index method was used to evaluate the water quality in Dali river basin,and the impact of land use structure on water quality in the buffer zone at different scales was identified.The results show that TN exceedes the standard the most serious among the four water quality parameters.The average value of Nemerow pollution index in the basin is 1.9,and the water body is slightly polluted;the average values of Nemerow pollution index are 2.3 in the main stream and 1.2 in the tributaries,the water quality of the tributaries is better than that of the main stream.The impact of cultivated land within 200 m on TN is greater than that within 100 m in the point buffer zone;the impact of grassland within 100 m on TP and the impact of cultivated land on NH_(3)-N is greater than that within 200 m in the river network buffer zone.Grassland is the main land use type that intercepts pollutants within 100 m;forest land is the main land use type that intercepts pollutants within 200 m.Cultivated land and building site land play a“source”role for TN,TP,and NH_(3)-N concentration in the point buffer zone and river network buffer zone;the“sink”function of forest land is more prominent at the point buffer zone,and the“sink”function of grassland is more prominent at the river network buffer zone.

关 键 词：水质 土地利用 逐步多元回归 内梅罗污染指数 枯水期 缓冲区 空间特征 黄河流域 

分 类 号：P64[天文地球—地质矿产勘探] X522[天文地球—地质学]