我国典型城市地表水水质综合评价与分析

应用内梅罗指数法对我国27个典型城市地表水水质进行评价，分析地表水水环境质量现状，揭示水质时空变化规律。结果表明：NH₃-N浓度、TP浓度、COD_Cr、BOD₅和COD_Mn为地表水主要超标因子，NH₃-N浓度为首要污染因子，水质主要受氮、磷营养盐及有机物影响。华北地区参与评估城市的水质级别均为较差；西北、东北、华东、华南、华中和西南地区参与评估城市的水质级别较好比例在50%以上。城市建成区水质优于非建成区；国控断面水质级别为较好。2012—2014年期间，典型城市地表水水质有明显的好转趋势，水质级别较差城市比例下降11%。西北和东北地区，因为人口密度小，经济发展相对不快，水质保持相对稳定，多数城市水质季节性特征不明显；华东地区地域辽阔，整体来看季度水质波动没有明显规律；华中和华北地区，受气候和降水量影响，城市水质季节性特征比较明显。

Comprehensive Evaluation and Analysis of Surface Water Quality for Typical Cities of China

Based on Nemerow index method, 27 typical cities all over China were chosen for the analysis of the present situation and spatio-temporal variation regulation of urban surface water. The results showed that TP, NH3-N, CODCr, BOD5 and CODMn were major factors exceeding the standards and NH3-N was the most serious, and the water was mainly affected by nitrogen, phosphorus and organic pollution. Water quality in North China area was poorer. Water quality in Northwest, Northeast, East China, South China, Central China and Southwest area was better and their ratio of good quality was over 50%. Water quality in built up area was better than that of the unbuilt up area. Water quality of the state-controlled sections was relatively good. The pollution of typical cities surface water quality alleviated from 2012 to 2014, and the proportion of cities with low-quality water had decreased by 11%. In Northwest and Northeast, most cities did not show clear seasonal characteristics due to low population density, relatively slow economy development and relatively stable water quality. In the vast East China region, water quality did not show obvious quarterly fluctuations. In Central China and North China, water quality showed relatively clear seasonal characteristics due to the influences of climate and rainfall.