温瑞塘河河网地区水质时空分布与评价

以典型的南方平原河网——温瑞塘河为研究对象，对河网区39个监测点的DO、TN、NO₃^--N、NH₄⁺-N、TP和COD含量进行了为期1 a的监测，揭示了其水质时空变化特征，并利用水质标识指数法对水体污染程度进行了评价。结果表明:温瑞塘河水质已经达到了劣Ⅴ类的程度，水体中氮磷含量严重超标，分别是国家Ⅴ类水标准的3.52倍和1.68倍。河网区水体水质时空分布特征明显，空间上污染程度呈现出三级河道 > 二级河道 > 主河道 > 郊区湿地的分布特征；时间上水质指标的变化较为复杂，与降雨量密切相关，大量降雨能够对河网区水体水质起到明显的改善作用。主河道的污染程度随流向具有累加作用。水体中氮磷比处于适合藻类生长的比值，具有发生水华的营养条件。

Spatiotemporal Variation and Assessment of Water Quality in Wenruitang River Network Areas

Based on the analysis of 6 hydrochemical variables that were monitored in 39 sites of the Wenruitang River in 2010, spatiotemporal variation features of water quality were investigated, the water quality status of Wenruitang River was also assessed with the comprehensive pollution index method. The results showed that the water quality in the river network areas was inferior to class Ⅴ, the concentrations of N and P exceeded the standard limits greatly and were 3.52 and 1.68 times of the class Ⅴ standard of the water quality, respectively. The temporal and spatial variations of water quality constituents in the river network areas were obvious. Pollution degree showed the trend that the third channel > the second river channel > the mainstream > suburb wetland; Seasonal change of water quality constituents was complex and closely related to precipitation. Heavy rains can improve the water quality obviously. The pollution degree was accumulated along with the water flow in the mainstream. The ratio of the N to P was suitable for algae growth, so the river network areas have the nutritional conditions of algal boom.