作　　者： ;

机构地区： 中国科学院广州地球化学研究所

出　　处： 《环境科学》 2021年第1期127-135,共9页

摘　　要： 农药的持续使用,使流域环境污染十分普遍,对其污染水平进行评估很有必要.相比传统的监测手段,与GIS结合的模型作为评估手段具有显著的优势,但是由于农药应用情景及相关排放量的数据不易获得,对流域农药的模拟评估造成了阻碍.本研究建立了一种农药排放量估算的方法,基于流域内作物种植情况及农药施用标准,通过使用情境分析和数学推演,可获得不同子流域单元的输入量;并以此为源输入数据,使用半分布式流域水文模型——SWAT(soil and water assessment tool)模型,以敌敌畏在东江流域为例进行模拟.模型的验证结果显示,模拟浓度与监测结果的差异值绝大多数在一个数量级以内,表明基于源输入估算的SWAT模型可有效评估流域农药的环境归趋.模拟结果表明,流域敌敌畏每年的排放量占到使用量的3.72%,河道内的降解等反应损失达2.35%.东江流域多数河段敌敌畏的质量浓度超过0.1μg·L^(-1),其污染需引起关注. The application of pesticides and their constant inputs have resulted in the universal contamination of the environments within watersheds,and it is essential to assess the level of contamination.Compared with traditional monitoring methods,models coupled with GIS show more obvious advantages.However,the difficult access to application scenarios and emission data of pesticides hinder the modeling and assessment of the pesticides used in watersheds.We established an emission estimation method of pesticides,which was based on the planting scenarios and pesticide application standards of different crops in administered regions and by situational analysis and mathematical deduction,the usage of each sub-basin was able to be derived.Then,by using the aforementioned results as source input data,a semi-distributed watershed hydrological,SWAT(soil and water assessment tool)model,was used to simulate the fate of dichlorvos in the Dongjiang River watershed as an example.The verification results show that the comparisons of magnitude between the simulation and the observations were almost within 1,indicating that the SWAT model,which is based on a source input estimation,was able to assess the environmental fate of pesticides in watershed effectively.Also,the modeling results indicated that the annual emission load of the dichlorvos in the watershed accounted for 3.72%of the usage.Moreover,the losses due to degradation and other reactions within the channels reach 2.35%.Most reaches of the Dongjiang River watershed have mass concentrations over 0.1μg·L^(-1),demonstrating that certain safety concerns exist.

关 键 词： 敌敌畏 排放量 模型 归趋 模拟 东江流域

领　　域： [环境科学与工程—环境工程]