摘要
西涧湖(原名城西水库)是安徽省滁州市唯一的地表水源,非点源污染已成为其水质恶化的重要原因。基于土地覆被格局,在GIS平台上建立分布式非点源污染运移截留过程模型。以磷素作为指示污染物,模拟了2010年及5种不同土地覆被情景下入库磷素量及截留量的响应。结果表明:2010年,流域向西涧湖的总磷输送量达到2461.20 kg,湖体西北部的市农科所、城郊居委会、水产研究所等地对水质危害最大。多数磷素在向湖体的运移过程中被各类土地覆被有效截留,总量达到5422.36 kg,占当年流域磷素总负荷的68.8%。5种情景下模拟入库磷素量总体符合农田>建城区>草地>林地的规律。在入湖河道周边布设不同宽度植被缓冲带的情景4、5收到了很好的减污效果;而退耕还林政策单纯以坡度作为指标,指导土地覆被的转化,对减轻水环境非点源污染功效较差。
Xijian Lake （formerly Chengxi Reservoir） is the unique surface water source of Chuzhou City, Anhui. Its water quality deterioration is mainly caused by the nonpoint source pollution. Based on the pattern of land use/land cover （LULC）, a model was established by GIS platform to simulate the quantity of nonpoint source pollution exported to the aquatic environment and retained by the different LULC on each cell on the platform of GIS. This study chose phosphorus as a pollutant surrogate and relevant data of the year 2010 were used in the model. The quantity of phosphorus exported to the lake and phosphorus retained were simulated under five different LULC scenarios. The results showed that in 2010, the total phosphorus exported to the lake was 2461.20 kg. Critical source areas of phosphorus mainly included the city＇s Institute of Agricultural Science, Chengjiao resident area, the Institute of Aquaculture in the northwestern of watershed. Most of the exported phosphorus was effectively retained by the different LULC in the process of transportation, and the total phosphorus retained by LULC was 5422.36 kg, accounting for 68.8% of the total phosphorus loads. The simulated results for the amounts of phosphorus exported to the lake under five different LULC scenarios were in the order of cropland 〉 built-up 〉 grassland 〉 forestland. The scenarios 4 and 5 that included vegetation buffer zones with different widths planted along the shore and on the intersection of runoff would largely improve the efficiency of phosphorus retention. However, the program of returning croplands to forests, which guided the land cover changes only based on the slope ranks, would be less efficient to prevent phosphorus from the watershed entering the aquatic environment.
出处
《生态学杂志》
CAS
CSCD
北大核心
2014年第4期1104-1113,共10页
Chinese Journal of Ecology
基金
安徽省省级环保科研计划项目(2011-001(1)号
2012-006号)
UNEP/GEF长江流域自然保护与洪水控制项目(IMIS:GFL-2328-2740-4822
PMS:GF/3030-04-05-01)资助
关键词
土地覆被
饮用水源地
非点源污染
西涧湖
情景分析
land cover water source areas nonpoint source pollution Xijian Lake scenario-analysis.
