太湖上游水源区河流水质对景观格局变化的响应关系--以东苕溪上游为例  

Response of water quality to landscape pattern change in the water source area of upper reaches of Lake Taihu:A case study in the upper reaches of Dongtiaoxi River

作　　者：范雅双 于婉晴 张婧 李雪 李小玉 Fan Yashuang;Yu Wanqing;Zhang Jing;Li Xue;Li Xiaoyu(School of Forestry and Bio-technology,Zhejiang A&F University,Hangzhou 311300,P.R.China)

机构地区：[1]浙江农林大学林业与生物技术学院,杭州311300

出　　处：《湖泊科学》2021年第5期1478-1489,共12页Journal of Lake Sciences

基　　金：国家自然科学基金项目(31870702,32071581);省部共建亚热带森林培育国家重点实验室自主研究课题项目(ZY20190203)联合资助.

摘　　要：景观格局演变作为人类活动的综合表征,通过改变水文过程和径流路径,从而影响非点源污染物的发生位置、迁移路径和转化过程,进而对流域水环境产生深刻影响.苕溪作为太湖的主要入湖河流之一,对太湖水环境有着关键的影响作用.本文以发源于杭州市临安区太湖源镇的东苕溪上游区域作为研究对象,在对河流水质进行两个时期监测的基础上,运用相关性分析、冗余分析和逐步回归分析等方法,综合景观组分指数和景观空间配置指数,在子流域尺度上量化景观指数对河流不同水质指标的解释能力,探讨河流水质对流域景观格局的响应规律.结果表明:1)东苕溪上游大部分监测点总氮浓度远超地表水Ⅴ类水质标准限值,但氨氮和总磷浓度整体较低,部分监测点可达Ⅰ类水质标准.2)在汛期,景观组成中流域的“源”景观比例是影响水质的重要因素,农业用地占比与硝态氮、总氮浓度呈显著正相关,建设用地占比对氨氮、总磷浓度影响显著;而在非汛期,景观配置因子,特别是表征斑块形状的周长面积分形维数(PAFRAC)对河流水质的影响极显著.3)无论是汛期还是非汛期,林地和草地对河流中污染物均具有显著的削减作用,是流域河流污染防治的关键“汇”景观.4)从整体上来看,河流氮、磷污染与人类活动强度密切相关,增加景观连通性、降低自然景观的破碎化程度可有效改善河流水环境.As a comprehensive representation of human activities,landscape pattern evolution affects the location,migration path and transformation process of non-point source pollutants by changing the hydrological process and flow path,and thus has a profound impact on the water environment of the basin.As one of the main rivers entering Lake Taihu,Tiaoxi River plays a critical role in the water environment of Lake Taihu.In this paper,the upper reaches of Dongtiaoxi River originating in Taihuyuan Town,Lin an District,Hangzhou City is taken as the research area.Based on the monitoring of river water quality in two periods,by integrating landscape component indexes and landscape spatial configuration indexes,methods like correlation analysis,redundancy analysis and stepwise regression analysis are used to quantify the interpretation ability of landscape indexes to different water quality indexes and discuss the response pattern of river water quality to the watershed landscape pattern on the sub-watershed scale.The results show that:1)The total nitrogen(TN)concentration far exceeds the surface water quality class V standard limit at most sampling sites in the upper reaches of Dongtiaoxi River,but the concentrations of ammonia nitrogen(NH 3-N)and total phosphorus(TP)are generally low,and some sampling sites could reach class Ⅰ water quality standard.2)During the flood season,in landscape composition,the proportion of“Source”landscape in the basin is an important contributor to water quality.Farmland has a significant positive correlation with nitrate-nitrogen(NO^(-)_(3)-N)and TN concentration,while construction land impacts NH 3-N and TP concentrations;in non-flood season,the water quality is dramatically impacted by landscape configuration factors,especially the perimeter-area fractal dimension characterizing the patch shape.3)Whether in flood season or non-flood season,forest and grassland can remarkably reduce pollutants in rivers,acting as the key“Sink”landscape for the prevention and control of river pollution

关 键 词：景观格局 水质 子流域 东苕溪上游 

分 类 号：X824[环境科学与工程—环境工程] P901[天文地球—自然地理学]