饮用水源地非点源风险遥感提取及定量评估

基于高空间分辨率卫星数据,以面向对象分类方法结合人工解译方法获得我国25个典型湖库型饮用水源地保护区的非点源风险空间分布,并基于水源地非点源风险指数(NPPRI)对非点源风险进行定量评价. 结果表明,我国典型水源地一级保护区与二级保护区内居民点、开采用地、农田类用地等非点源风险普遍存在,部分水源地还存在水产养殖、旅游用地、畜禽养殖等风险源. 在监测的25个水源地中,水源地非点源风险隐患为高、较高、偏高、中度、低的比例分别为12%、4%、44%、20%、20%,风险隐患中度及以下的为40%,偏高及以上的为60%,说明水源地中非点源风险隐患总体明显. 另一方面,25个水源地中,非点源风险指数最大为42.0,最小为0.8,表明全国水源地非点源风险现状差异较大,需引起重视. 水源地非点源风险的大小与保护区面积没有正相关关系,各水源地非点源风险程度在全国的空间分布没有明显的空间分布格局,而主要和水源地与城市距离、当地相关部门对水源地重视程度、配套的管理措施及历史状况等因素相关. 

Non-Point Source Pollution Risk Mapping and Quantitative Assessment for Surface Water Source Using High Spatial Resolution Satellite Data

Environmental safety of drinking water has become one of the most important tasks in environmental protection. Risk prevention for the drinking water sources is a fundamental way to protect the safety of the water source. The key for risk prevention of the drinking water sources is to identify the risk of drinking water source, especially the non-point source pollution risk. However, it is difficult to obtain the information of the non-point source pollution risk through the conventional observational/statistical methods. Since remote sensing is a means of macro observation, it has the ability to instantaneously and easily retrieve surface information of water sources. The non-point source pollution risks of 25typical drinking water source protection areas were mapped based on the high spatial resolution satellite data using the methods of manual interpretation combined with object-oriented classification. Furthermore, non-point source pollution risks index (NPPRI) was calculated for the typical water sources. We made the following observations:firstly, the residential areas, mining land, and farmland were widespread in the protection zone of water sources in China. The aquaculture site, tourism land, livestock and poultry farming areas existed in part of water sources. Secondly, according to their risks drinking water source can be divided into five groups, high (12%), relative high (4%), slightly high (44%), moderate (20%) and low (20%), respectively. In other words, the percentage of drinking water sources with the medium and low risk was 40% and the high and more serious risk was accounted for 60%. Thus, it is obvious for the potential risks of non-point sources of water sources. Furthermore, the maximum and minimum values of NPPRI were 42.0and 0.8respectively. This result showed that the difference of the non-point source pollution risk is significant or water source, which is needed to pay more attention. Lastly, the non-point source pollution risks index was not related to the water source protection area at all and no clear spatial distribution patterns of the non-point pollution risk of various water sources is found. The non-point source pollution risk was related to the attention from the local water source administrations, and the distance from the water source to the city.