拉萨河流域非点源污染输出风险评估  

Risk assessment of non-point source pollution export in Lasahe basin

作　　者：方广玲[1,2] 香宝[1,2] 杜加强[1,2] 王宝良[1,2] 张立坤[1,2] 胡钰[3] 徐杰[1,2] 

机构地区：[1]中国环境科学研究院,北京100012 [2]国家环境保护区域生态过程与功能评估重点实验室,北京100012 [3]北京师范大学水科学研究院,北京100875

出　　处：《农业工程学报》2015年第1期247-254,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家环保公益性行业科研专项(201209032)

摘　　要：有效识别流域非点源污染高风险区,对污染控制与管理以及水环境质量改善具有重要意义。该研究以拉萨河流域为研究对象,构建包括降雨、地形和施肥影响因子的输出风险模型,识别流域各级非点源污染输出风险的地域单元。结果表明:1996年和2010年,非点源污染输出风险概率分别为50.0%和46.3%;非点源污染风险处于较高以上程度的区域面积分别为12 985.8和11 628.0 km2,占全区总面积的38.9%和34.9%;与1996年相比,2010年非点源污染风险程度由低级别向高级别转换的总面积约为6 674.3 km2。拉萨河流域非点源污染发生的风险概率为中等,风险程度在局部范围内有所下降,主要表现在高风险区域面积减少、低风险区域面积增加,但是中等和较高风险区域面积有增加趋势。土地利用变化、农业生产和水土流失是非点源污染发生的主要原因,应巩固生态环境综合治理成果,提前应对可能出现的非点源污染问题,制定生态农业发展规划,营造控制非点源污染迁移的植被缓冲带。Identification of the high risk area of non-point source pollution has important practical significance to control non-point source pollution and improve the water environment quality. Lasahe River basin located in the Tibet Autonomous Region of China is important drinking-water source for Lhasa City, Linzhou County and Dangxiong County. Because the underdevelopment of industry and the less discharge of industrial pollutants in this area, non-point source pollution is the most important contributing factor for water pollution. Lhasa River basin is the region of agricultural production base with the densest population in the Tibet Autonomous Region. This study built the output risk model that includes rainfall, topography, and fertilization influence factor, identification the output risk region unit from basin non-point source pollution at all levels object. The risk probability of non-point source pollution was classed into five levels： lowest, lower, moderate, higher and highest. Data used in this study were mainly from remote sensing image, statistical yearbook, and the parameters in output risk model were collected from the literatures. The results showed that risk probability of non-point source pollution output in 1996 and 2010 was 50%and 46.3%respectively. 17.5%in 1996 and 12.6%in 2010 of the study area showed that risk probability of non-point source pollution was more than 70%. The risk probability of non-point source pollution was spatially heterogeneous, corresponding with the attributes of land use types. The areas with highest risk of non-point source pollution were concentrated in farmland, where agricultural activities strengthened, and concentrated in unused land with great ecological vulnerability and sensitivity to external interference. Areas with lowest and lower risk of non-point source pollution mainly distributed in grassland, which has relative stability and robustness. Our study also found that risk probability of non-point source pollution was closely related with slope, the risk enhan

关 键 词：污染 风险分析 模型 输出风险模型 拉萨河流域 

分 类 号：X820.4[环境科学与工程—环境工程]