基于水文分割法的流溪河干流典型断面非点源污染负荷估算

针对流溪河非点源污染防治较严峻局面,对流溪河非点源负荷进行了研究。2013—2014年,对流溪河干流温泉、牛心岭、人和、河口断面进行了203 d的水质及水量监测。根据监测结果结合水文分割法和平均浓度法对各断面的非点源污染负荷进行了计算,并分析了非点源污染的特点。结果表明:流溪河干流典型断面污染物以NH3-N、TN和TP为主;越往下游,监测断面各指标平均浓度越大,水质越差;上游断面洪水期各主要指标浓度大于枯水期,下游断面则是枯水期各主要指标浓度大于洪水期;监测断面各指标非点源污染负荷占总负荷的比例为44.22%~96.17%,平均为76.99%;从上游往下游,非点源污染物负荷占总负荷的比例在减小;各断面年污染负荷基本上是以洪水期负荷为主,洪水期污染负荷则以非点源污染负荷为主;河口断面污染物年总负荷中,58.74%的TN、67.22%的TP和65.45%的COD来源于非点源污染。非点源污染在流溪河水体污染中占较大比重,对水质影响不容忽视。

Hydrological segmentation method-based estimation on non-point source pollution loads of typical cross-sections along mainstream of Liuxihe Ｒiver

Aiming at the more serious situation of the control of the non-point source pollution along Liuxihe Ｒiver，the non-point source pollution load therein is studied herein，for which both the water quality and the water amount are monitored on the crosssections ( Wenquan Dam，Niuxinling Dam，Ｒenhe Dam and the estuary) of the mainstream of the river for 203 days from 2013 to 2014. The non-point source pollution loads of all the cross-sections are calculated with the hydrological segmentation method and the mean concentration method in accordance with the monitoring results，and then the characteristics of the non-point source pollution is analyzed as well. The result shows that the pollutants of the typical cross-sections of the mainstream of Liuxihe Ｒiver are mainly NH3 － N、TN and TP; While the farer the distance from the downstream is，the larger the mean concentrations of all the indexes of the monitored cross-section are to be and the poorer the water quality is to be therein. The concentrations of all the main indexes of the cross-sections of the Upper Liuxihe Ｒiver during flood season are larger than those during the dry season. However，the concentrations of all the main indexes of the downstream cross-sections during dry season are larger than those during flood season. The non-point source pollution loads of all the indexes of the monitored cross-sections account for 44. 22% to 96. 17% of the total pollution load with the mean value of 76. 90% ，while the proportion of the non-point source pollution load in the total pollution load is gradually decreased from the upstream to the downstream. Generally，the annual pollution loads of all the cross-sections are mainly the loads during flood season，while the pollution loads during flood season are mainly the non-point source pollution loads. In the annual total pollutant load of the cross-section at the river estuary，58. 74% of TN，67. 22 of TP and 65. 45% of COD come from the non-point pollution，thus the proportion of the non-point source pollution in the water pollution of Liuxihe Ｒiver is larger，from which the impact on water quality cannot be neglected.