Li Hua-Lin, Zhang Jian-Jun, Zhang Yao-Fang, Chang Guo-Liang, Shi Di-di, Xu Wen-Jing, Song Zhuo-Yuan, Yu Pei-Dan, Zhang Shou-Hong
School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China.
Beijing Water Science Technology Institute, Beijing 100048, China.
Huan Jing Ke Xue. 2021 Jun 8;42(6):2796-2809. doi: 10.13227/j.hjkx.202010225.
Non-point source pollution has become an important factor affecting the aquatic ecological environment and human health, and the analysis of spatial-temporal variations in non-point source pollution risks is an important prerequisite for pollution control. Based on land-use and land-cover data from 1980 to 2020, the potential non-point source pollution index (PNPI) model was applied in the upper Beiyun River Basin using different weighting methods. The results showed that:① The potential risk of non-point source pollution is high in the southeast and low in the northwest of the basin. Between 1980 and 2020, the total area of extremely high-risk and high-risk non-point source pollution regions showed a decreasing trend, and the main types of land use for extremely high-risk and high-risk regions gradually evolved from paddy fields, drylands, and orchards to urban and rural residential land; ② The weighting of the land use index determined by the mean-square deviation decision, entropy, coefficient of variation, and expert scoring methods was largest among the three PNPI indices, with average weightings of 0.46, 0.53, 0.45, and 0.48, respectively. However, the weightings for runoff and distance indices determined by different weighting methods were notably different, and the proportions of regions with different levels of non-point source pollution risk also varied; ③ The exponential function method, which describes the relationship between source factors and transport factors by constructing the exponential functions of land use, runoff, and distance indices, provided results that are more consistent with the spatial distribution characteristics of non-point source pollution risk in the basin. The proportions of extremely low-risk and extremely high-risk regions are 54.22% and 6.23%, respectively. These results provide scientific reference for risk analysis and the control of non-point source pollution in this basin.
非点源污染已成为影响水生生态环境和人类健康的重要因素，分析非点源污染风险的时空变化是污染控制的重要前提。基于1980年至2020年的土地利用和土地覆盖数据，采用不同加权方法将潜在非点源污染指数（PNPI）模型应用于北运河流域上游。结果表明：①流域东南部非点源污染潜在风险高，西北部低。1980年至2020年，极高风险和高风险非点源污染区域总面积呈下降趋势，极高风险和高风险区域的主要土地利用类型逐渐从水田、旱地和果园演变为城乡居民用地；②均方差决策、熵、变异系数和专家评分法确定的土地利用指数权重在三个PNPI指数中最大，平均权重分别为0.46、0.53、0.45和0.48。然而，不同加权方法确定的径流和距离指数权重差异显著，不同非点源污染风险水平区域的比例也有所不同；③通过构建土地利用、径流和距离指数的指数函数来描述源因素与传输因素之间关系的指数函数法，其结果与流域非点源污染风险的空间分布特征更为一致。极低风险和极高风险区域的比例分别为54.22%和6.23%。这些结果为该流域非点源污染的风险分析和控制提供了科学参考。
