基于逆建模技术的淮河干流长台关-息县段入河污染负荷评估

Estimation of pollution load in Changtaiguan-to-Xixian section of main stream of Huaihe River based on inverse modeling technology

以淮河上游长台关-息县段为研究对象,以2008年为算例,根据研究区域汇流特征,建立分布式源模型,基于贝叶斯统计方法进行逆建模,利用断面水质序列实测资料,测算区域入河污染负荷及主要水质因子降解系数。结果表明:淮河上游长台关-息县段NH3-N、COD入河污染负荷总量分别为1.7万t/a、8.9万t/a;受主要入流面源污染负荷季节性影响,NH3-N入河污染负荷为657.55～2 014.99 t/月,COD入河污染负荷为3897.73～13311.83 t/月;研究区域水体环境NH3-N、COD降解系数分别为0.356/d、0.202/d,NH3-N、COD负荷模拟值和实测值的相关系数分别为0.943、0.979。

A distributed source model was established according to the confluence characteristics of the Changtaiguan-to- Xixian section upstream of the Huaihe River, through a case study from 2008. The inverse modeling was conducted based on the Bayesian statistical method. The measured data of the water quality at the studied section were used to calculate the pollution load flowing into the river and the degradation coefficients of the main water quality factors. The results show that the total pollution loads of NH3-N and COD in the study area were 17 000 t per year and 89 000 t per year, respectively. Affected by seasonal non-point source pollution loads, the pollution loads of NH3-N and COD were 657.55 t to 2014.99 t per month and 3 897.73 t to 13 311.83 t per month, respectively. The degradation coefficients of NH3-N and COD were 0.356 per day and 0. 202 per day, respectively. The correlation coefficients between simulated and measured values of NH3-N and COD were 0.943 and 0.979, respectively.