基于ReNuMa模型的武烈河氮磷负荷模拟及来源解析

Simulation and Source Analysis of Nitrogen and PhosphorusLoading of Wulie River Based on ReNuMa Model

武烈河是承德市工农业及居民生活用水的重要水源,开展流域污染物负荷模拟及来源解析对流域水污染控制和管理具有重要意义。采用ReNuMa模型对武烈河磷矿上游断面子流域2015—2020年的水文径流过程和全流域2018—2020年的总氮(TN)、总磷(TP)污染负荷量进行模拟,解析氮磷负荷的来源及贡献率。结果表明:(1)2018—2020年,年均TN负荷量为655.98 t,各污染来源贡献率由大到小依次为地下水(30.68%)>点源(25.63%)>腐生系统(25.16%)>沉积物源(12.85%)>地表径流(5.68%);2018—2020年,年均TP负荷量为8.12 t,各污染来源贡献率由大到小依次为沉积物源(49.58%)>点源(16.54%)>地下水(15.01%)>腐生系统(13.20%)>地表径流(5.67%)。(2)年内氮磷污染负荷入河量以非点源为主,分别占总负荷的74.37%和83.46%,点源与非点源的贡献占比受汛期和非汛期影响显著,非汛期以点源形式输入的负荷占比远超汛期(6—9月)的。本研究结果能够为流域水质改善和污染管控方案的制定提供借鉴。

Wulie River is an important source of water for industrial,agricultural and residential use in Chengde,and the modelling of pollutant loads and source analysis in watersheds is of great importance to the control and management of water pollution in watersheds.ReNuMa model was used to simulate the hydrological runoff process from 2015 to 2020 and the total nitrogen(TN)and total phosphorus(TP)pollution load of the whole basin from 2018 to 2020 in the upper section of Phosphate Mine in Wulie River basin,the source and contribution rate of nitrogen and phosphorus load were analyzed.The results show that:①From 2018 to 2020,the average annual TN load was 655.98 t,and the contribution of each pollution source in descending order was groundwater(30.68%)>point source(25.63%)>Saprophytic system(25.16%)>sediment source(12.85%)>surface runoff(5.68%).From 2018 to 2020,the average annual TP load was 8.12 t,the contribution of each pollution source in descending order was sediment sources(49.58%)>point sources(16.54%)>groundwater(15.01%)>Saprophytic system(13.20%)>surface runoff(5.67%).②Nitrogen and phosphorus pollution loads into the river during the year were dominated by non-point sources,accounting for 74.37%and 83.46%of the total load respectively,the proportions of contribution from point and non-point sources are significantly influenced by the flood and non-flood periods,the proportion of load input as point sources during the non-flood period is far exceeding that of the flood period from June to September.This study can provide scientific guidance for the development of targeted water quality improvement and pollution control programmes in the basin.