渭河流域天水段非点源污染模拟及驱动因素分析  

Modelling and Driving Force Analysis of Non-Point Source Pollution in Tianshui Section of Weihe River Basin

作　　者：任衍淦 张亚群 温成成 吴明艳 尚婷婷 REN Yangan;ZHANG Yaqun;WEN Chengcheng;WU Mingyan;SHANG Tingting(Gansu Academy Eco-Environmental Sciences,Lanzhou 730000,China;College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]甘肃省生态环境科学设计研究院,甘肃兰州730000 [2]兰州大学资源环境学院,甘肃兰州730000

出　　处：《环境科学研究》2025年第2期294-303,共10页Research of Environmental Sciences

基　　金：黄河流域生态保护和高质量发展联合研究项目(No.2022-YRUC-01-050203);甘肃省自然科学基金项目(No.23JRRA1275);2024年陇原青年创新创业人才团队项目(No.A2024002)。

摘　　要：渭河是黄河最大支流,流域内非点源污染形势严峻。开展流域非点源污染负荷模拟、关键源区划分及驱动因素识别对于落实黄河国家战略、推动流域水生态治理具有重大意义。该研究基于遥感分布式面源污染评估模型(DPeRS)和随机森林回归模型,模拟2022年渭河流域天水段非点源污染情况,并探讨不同下垫面属性(高程、坡度、土壤类型和土地利用类型)对流域非点源污染产生的相对重要性。结果表明:①2022年渭河流域天水段各县区农田氮、磷表观平衡量差异显著,其中,武山县氮、磷表观平衡量均最大。②总氮(TN)、总磷(TP)、化学需氧量(COD_(Cr))的平均污染强度分别为182.2、18.4、124.4 kg/km^(2),空间上,秦安县的TN和TP浓度较高,而张家川回族自治县的COD_(Cr)浓度较高。③高程和坡度对TN、TP、COD_(Cr)三类污染指标的空间分布均具有重要作用,土壤类型则主要影响TN和TP的分布,而土地利用类型对三类非点源污染的负荷影响较小。因此,渭河流域天水段的非点源治理应重点关注秦安县、张家川回族自治县两地,其中高程、坡度、土壤类型对TN、TP、COD_(Cr)污染强度与分布有着关键影响,研究结果可为地方非点源污染治理提供参考。The Weihe River is the largest tributary of the Yellow River,and the situation of prevention and control of non-point source pollution in the basin is still serious.Simulating pollution loads,classifying key source areas,and identifying drivers of non-point source in the basin are essential for implementing the national strategy for the Yellow River and managing the basin's water ecology.In this study,the Diffuse Pollution Estimation with Remote Sensing(DPeRS)model was used to calculate the non-point source pollution in the Tianshui section of the Weihe River Basin in 2022,and a random forest regression model was employed to determine the key effect of the different underlying surface types(i.e.,elevation,slope,soil type,land use type)on non-point source pollution in the watershed.The results showed that:(1)The apparent balance of nitrogen and phosphorus in the different counties and districts of the Tianshui City varied significantly,of which Wushan County was the maximum.(2)Based on the simulation result of nonpoint source pollution,the average pollution intensity of total nitrogen(TN),total phosphorus(TP),chemical oxygen demand(COD_(Cr))were 182.2,18.4,124.4 kg/km^(2),respectively.In the spatial scale,the Qin´an and Qingshui Counties in the north of the study area belonged to the high-value areas of the pollution intensity of TN and TP,while the Zhangjiachuan County in the northwest of the study area belonged to the high-value areas of COD_(Cr).(3)According to the analysis result of the influencing factors,the geographic elevation and slope had important influence on the three types of non-point source pollutants(i.e.,TN,TP and COD_(Cr)),and the soil type greatly affect the pollution generation of TN and TP,while the landuse type had limited influence on the pollution generation of nonpoint source.Therefore,the control of non-point source pollution in the Tianshui section of the Weihe River basin should focus on Qin'an County and Zhangjiachuan Hui Autonomous County.Especially,the elevation,slope,and soil type

关 键 词：非点源污染 遥感分布式面源污染评估模型(DPeRS) 随机森林回归模型 渭河流域 

分 类 号：X171[环境科学与工程—环境科学]