不同尺度土地利用方式对鄱阳湖湿地水质的影响  

Effects of Land Use Types at Different Spatial Scales on Water Quality in Poyang Lake Wetland

作　　者：方娜 刘玲玲 游清徽[4] 田娜[5] 吴燕平 阳文静[1,2,3] FANG Na;LIU Ling-ling;YOU Qing-hui;TIAN Na;WU Yan-ping;YANG Wen-jing(Key Laboratory of Poyang Lake Wetland and Watershed Research,Ministry of Education,Jiangxi Normal University,Nanchang330022,China;College of Geography and Environment,Jiangxi Normal University,Nanchang 330022,China;Jiangxi Provincial Key Laboratory of Poyang Lake Comprehensive Management and Resources Exploitation,Jiangxi Normal University,Nanchang 330022,China;College of Life Sciences,Jiangxi Normal University,Nanchang 330022,China;Institute of Ecological Economics,Jiangxi University of Finance and Economics,Nanchang 330032,China)

机构地区：[1]江西师范大学鄱阳湖湿地与流域研究教育部重点实验室,南昌330022 [2]江西师范大学地理与环境学院,南昌330022 [3]江西师范大学江西省鄱阳湖综合治理与资源开发重点实验室,南昌330022 [4]江西师范大学生命科学学院,南昌330022 [5]江西财经大学生态经济研究院,南昌330032

出　　处：《环境科学》2019年第12期5348-5357,共10页Environmental Science

基　　金：国家自然科学基金项目(41561097);江西省教育厅科学研究项目(GJJ170199,GJJ150334);江西省自然科学基金项目(20142BAB213023);鄱阳湖湿地与流域研究教育部重点实验室开放基金项目(PK2017004,PK2019004)

摘　　要：基于鄱阳湖湿地30个采样点的实测水质数据,分析鄱阳湖湿地水质的现状及其与周边不同尺度土地利用方式的相关性.结果表明,鄱阳湖湿地水质介于Ⅲ类至Ⅴ类之间,平均处于Ⅳ类的状态.湿地水体主要污染物是总氮(TN)和总磷(TP),叶绿素a(Chl-a)质量浓度和高锰酸盐指数值相对较低.不同尺度的土地利用方式与水质参数之间均存在显著的关联性,500m缓冲区内的土地利用方式对高锰酸盐指数空间分异的解释度最大,而1 km缓冲区对Chl-a、TN、TP及总体水质空间分异的解释度最大.缓冲区尺度的土地利用方式对水质的解释度要高于小流域尺度.居民用地与所有水质参数呈显著正相关,耕地与TN、TP呈显著正相关. 200 m缓冲区内的河流与TN、TP呈显著正相关,表明河流入湖口附近采样点的氮磷质量浓度较高,河流输入可能是鄱阳湖氮磷的重要来源.湖泊与Chl-a、TN和TP之间呈显著负相关,表明相对于鄱阳湖的主湖区,周边湿地起着污染物“源”的作用.该研究表明,控制小尺度(≤1 km)的土地利用格局、特别是居民用地和耕地的面积占比及河流污染物输入对于鄱阳湖的水质保护十分重要.Water is a crucial environmental element that affects various ecological processes in wetlands.Poyang Lake is the largest freshwater lake in China,where seasonal variation in water level generates a unique landscape of wetland in the dry season-a critical habitat for Siberian migratory birds.Nevertheless,the water quality of the Poyang Lake wetland has not been systematically and rigorously studied.In this study,we analyzed the spatial pattern of water quality in the Poyang Lake wetland based on four key physicochemical parameters[i.e.chlorophyll-a(Chl-a),chemical oxygen demand using permanganate index,total nitrogen(TN),total phosphorus(TP)]at 30 randomly selected sample sites.We also investigated the relationships between water quality parameters and land use types at different spatial scales.We found that water quality at the sample sites varied from level III(fair)to level V(very poor),with an average of level IV(poor).TN and TP were the main pollutants in the water of Poyang Lake wetland,while Chla content and permanganate index were comparatively low.There were significant correlations between water quality parameters and land use types at different spatial scales.Land use types within a 500 m buffer zone had the strongest explanatory power on the spatial variation of permanganate index,while those within a 1 km buffer zone had the strongest relationships with Chl-a,TN,TP,and the overall water quality.Land use types in buffer zones exhibited stronger explanatory power than those at watershed scales.Built-up land was positively correlated with all water quality parameters,while farmland had positive relationships with TN and TP.Rivers within a 200 m buffer zone were positively correlated with TN and TP,indicating that the river input might be an important source of nitrogen and phosphorus in Poyang Lake.The percentage of lake area had negative relationships with Chl-a,TN,and TP,suggesting that wetland was a source of pollutants compared with the main region of Poyang Lake.Our study shows that controlling the

关 键 词：水质 土地利用 空间尺度 鄱阳湖湿地 多元线性回归 

分 类 号：X524[环境科学与工程—环境工程]