摘要
识别流域主要污染源和首要污染物及探究该流域污染空间分布特征是成功实现流域水环境管理的关键之一。以沱江流域为研究区域,以28个县为基本计算单元,首先采用排污系数法估算各污染源的化学需氧量(COD)、氨(NH_(3)-N)、总氮(NT)和总磷(TP)污染负荷。然后采用等标污染排放量评价法确定该流域的主要污染源和污染物及识别污染严重区域。最后利用探索性空间数据分析(ESDA)探索各污染物等标污染排放量的空间分布格局。结果表明,(1)城市生活污染源对COD、NH_(3)-N和TN污染负荷的贡献率分别为53.14%、42.41%和35.76%,这表明城市生活污染源对沱江流域的污染负荷影响更大,该污染源是COD、NH_(3)-N和TN污染物的主要来源,城填生活污染源和畜禽养殖业污染源对TP污染负荷的贡献率分别为29.88%和36.31%。(2)从总量来看,该流域COD、NH_(3)-N、TN和TP的等标污染排放量为2.24×10^(4 )m^(3)、3.75×10^(4) m^(3)、8.01×10^(4) m^(3)和6.39×10^(4) m^(3),TN是沱江流域的主要污染物。从空间角度来看,COD、NH_(3)-N、TN等标污染排放量的空间分布特征由大到小依次为中游、上游、下游。中游NH_(3)-N、TN和TP等标污染排放量最大的区县是安岳县,分别达2447.73 m^(3)、5313.28 m^(3)和4426.64 m^(3),COD等标排污量最大值出现在仁寿县,达1286.30 m^(3);上游COD、NH_(3)-N、TN、TP等标污染排放量最高值出现在旌阳区,分别达到1118.96 m^(3)、1558.69 m^(3)、3382.95 m^(3)和2802.99 m^(3);下游COD、NH_(3)-N、TN和TP等标污染排放量最大值出现在泸县,分别达979.27 m^(3)、1795.99 m^(3)、3832.07 m^(3)和3378.77 m^(3)。旌阳区、新都区、龙泉驿区和安岳县的等标污染排放量高且强度大。(3)各污染负荷的等标污染排放量的空间自相关指标均较大。这表明各污染负荷等标污染排放量的空间分布特征呈现集聚趋势。污染高风险地区主要出现在沱江流域中部,即雁江区、仁寿县和安岳县等区县,尤其是雁江区各污染物污染风险水平均最高。低风险地区主要集中在荣县、贡井区、自流井区、沿滩区和富顺县等下游区县。
It is key to obtain successful water environmental management across watersheds through exploring the spatial distribution characteristics of water environmental pollution and distinguishing the main pollution sources and primary pollutants in watersheds.Taking the Tuojiang River basin as the study site and its 28 counties as the basic calculated units,this study firstly estimated the chemical oxygen demand(COD),ammonia(NH_(3)-N),total nitrogen(TN),and total phosphorus(TP)pollution loads from individual pollution sources by using pollution discharge coefficient method.And then this paper determined the main pollution sources and the primary pollutants and distinguish the severely polluted areas in the watershed by applying the equivalent pollution discharge method.Finally,this project explored the spatial distribution pattern of the equivalent pollution discharge amounts of individual pollutants using Exploratory Spatial Data Analysis(ESDA).The results are as following:(1)The contribution to COD,NH_(3)-N and TN pollution loads originated from urban domestic pollution sources are 53.14%,42.41%,and 35.76%,respectively.It suggests that urban domestic pollution source contributes much more pollution loads to the watershed and this pollution source is the primary source of COD,NH_(3)-N and TN pollutants.While the contribution to TP pollution load derived from urban domestic pollution sources and livestock breeding pollution sources are 29.88%and 36.31%,respectively.(2)From the total amount perspective,the equivalent pollution discharge amounts of COD,NH_(3)-N,TN,and TP across the whole watershed are 2.24×10^(4) m^(3),3.75×10^(4) m^(3),8.01×10^(4) m^(3) and 6.39×10^(4) m^(3),and TN is the main pollutant of the Tuojiang River Basin.Form spatial perspective,the spatial distribution characteristics of equivalent pollution discharge amounts of COD,NH_(3)-N,and TN are as following:middle reaches>upper reaches>lower reaches.For the middle reaches,all the maximum values of equivalent pollution discharge amounts of NH_(3)-N,TN and TP appear in Anyue county,the values are up to 2447.73 m^(3),5313.28 m^(3),and 4426.64 m^(3),respectively.While the maximum values of equivalent pollution discharge amount of COD appear in Renshou county,the values are up to 1286.30 m^(3).For the upper reaches,all the maximum values of equivalent pollution discharge amounts of COD、NH_(3)-N,TN and TP appear in Jingyang county are up to 1118.96 m^(3),1558.69 m^(3),3382.95 m^(3) and 2802.99 m^(3),respectively.For lower reaches,all the maximum values of equivalent pollution discharge amounts of COD、NH_(3)-N,TN and TP appear in Lu county are up to 979.27 m^(3),1795.99 m^(3),3832.07 m^(3) and 3378.77 m^(3),respectively.(3)Spatial autocorrelation indexes of equivalent pollution discharge amounts of all pollution loads are larger.It indicates that the spatial distribution characteristics of equivalent pollution discharge amounts of each pollution load show agglomeration trends.The high-risk areas of pollution mainly occur in the middle reaches of the Tuojiang River Basin,which are Yanjiang,Renshou,and Anyue Counties.While low-risk areas are mainly concentrated in the lower reaches including Rong,Gongjing,Ziliujing,Yantian,and Fushun Counties.Especially,Yanjiang County is always at the highest pollution risk level for all pollution.Jingyang,Xindu,Longquanyi,and Anyue County have large emissions and high intensity of equivalent pollution discharge.
作者
樊敏
肖宇婷
姚婧
谌书
赵丽
FAN Min;XIAO Yu-ting;YAO Jing;CHEN Shu;ZHAO Li(School of Environment and Resource,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2022年第3期1619-1632,共14页
Journal of Safety and Environment
基金
四川省科技计划重点研发项目(2019YFS0057,2019YFS0055,2020YFS0306)
国家自然科学基金项目(41601088)。
关键词
环境学
排污系数
源解析
探索性空间数据分析(ESDA)
沱江流域
environmentalology
pollution discharge coefficient
source apportionment
Exploratory Spatial Data Analysis(ESDA)
Tuojiang River basin
