太湖地区典型小城镇降雨径流NP负荷空间分布的研究

Distribution of Nitrogen and Phosphorus Loads in Runoff in a Representative Town in Tailake Region

通过对太湖地区典型乡镇镇区交通干道商业区、镇居民区和附近农村居民点的8次降雨地表径流的调查,分析了小城镇地表径流的TN、TP、NH4+-N、NO3--N含量的空间分布状况。结果认为,小城镇及附近农村降雨地表径流氮、磷负荷是区域重要的非点源污染源。镇附近农村居民点降雨径流TN、TP浓度分别达7.26±4.43mg·L-1和2.21±0.90mg·L-1,镇商业区和居民点降雨径流TN、TP浓度相对较低,但远高于周围水提浓度,大大超过地面水Ⅴ类水质标准。TN/TP比值的差异说明,3类观测区域降雨径流污染物来源明显不同。

Distribution of nitrogen and phosphorus contents in runoff of three functional areas in a representative town was investigated. The three representative areas are: traffic and commence area, residence area in town, countryside residence area nearby. The results showed that contents of water dissolvable total nitrogen and water dissolvable phosphorus in runoff in countryside residence area nearby the town significantly surpassed that in traffic and commence area, and residence area in town. The contents of water dissolvable total nitrogen and water dissolvable phosphorus in runoff of all the three functional area were higher than that of surrounding water, and far surpassed that of Ⅴ types water of national standard. The variation of the ratios of the contents of water dissolvable total nitrogen and water dissolvable phosphorus elucidated the different origination of pollution.