黄河流域水污染排放特征及污染集聚格局分析

掌握污染源排放特征及其空间差异，是在流域尺度提升水污染治理水平的重要基础.该研究分别从污染源的活动水平（简称“活动水平”）、污染物产生、污染物去除和污染物排放4个方面选取了28个指标，对黄河流域60个市州主要水污染物排放特征开展了现状评价和聚类分析.采用污染分布的地理集中度指数表征各市州污染集聚格局，并利用空间分析模型Global Moran's I和G_i*指数判断污染排放的空间集聚趋势与冷热点地区.结果表明:按照水污染排放特征的差异，黄河流域不同地区在水污染格局上可划分为高排放强度区、高排放绩效区、污染集聚区和低排放绩效区；水污染物排放与经济发展格局分布一致，上游、中游到下游地区呈现明显的阶梯型分布，上游地区单位水资源利用效率和排放绩效低，下游地区区域性污染集聚效应明显；山西省、河南省和山东省沿黄城市在空间上表现为区域性连片污染集聚，集中分布在晋中城市群和中原城市群.针对当前黄河流域水污染排放特征和空间集聚格局，建议制定统一的生态环境保护与治理策略，加强中下游城市群的污染协同控制. 

Discharge Characteristics and Pollution Aggregation Pattern of Water Pollution in Yellow River Basin

Understanding the discharge characteristics of pollution sources and their differences in geographical space is an important basis for improving water pollution control level in basin scale. Discharge characteristic evaluation and cluster analysis of basic water pollutants in 60 cities in the Yellow River Basin were carried out by 28 characteristic evaluation indexes, which were selected from four aspects including activity level of pollutant sources, pollutant generation, pollutant removal and pollutant discharge. The geographical concentration index of pollution distribution was used to calculate and characterize the pollution concentration patterns of each city. The spatial autocorrelation of Global Moran''s I and G_i^* indexes was used to analyze the Global spatial autocorrelation and local spatial autocorrelation, respectively, so as to judge the spatial agglomeration trend of pollution discharge and identify cold and hot spots. The results showed that different areas in the Yellow River Basin can be divided into high emission intensity area, high emission performance area, pollution agglomeration area and low emission performance area according to the differences of water pollution discharge characteristics. Besides, the spatial distribution patterns of water pollutant discharge were in consistent with economic development spatial pattern. The upstream, middle and downstream regions showed an obvious step-type distribution. Specifically, it showed low unit water resource utilization efficiency and discharge performance in upstream region, and significant regional pollution concentration effect in downstream region. Moreover, the cities along the Yellow River in Shanxi, Henan and Shandong provinces showed regional agglomeration of pollution, especially concentrated in Jinzhong City group and central plains city group. In view of the current pollution discharge characteristics and spatial agglomeration pattern in the Yellow River Basin, a unified strategy of ecological environment protection and governance should be put forwarded, developing and tightening coordinated control of pollution in the middle and downstream city clusters should be developed and strengthened.