Study On Evaluation Of Heavy Metal Scavenging Capacity Of Soil In Small And Medium-Sized Watershed

The main research contents of this paper are the content of heavy metals in the Xiahe River Basin,the pollution capacity and the pollution evaluation.The contents of heavy metals and pollution in the Xiahe River Basin were studied by collecting the samples of the Xiahe River and the main tributaries.Based on the hydrological data of the Daxia River Basin,the paper uses the blind number theory to discuss the pollutant carrying capacity of heavy metals,and analyzes the actual pollutant capacity of heavy metals in the Xiahe River Basin.A fuzzy comprehensive evaluation model based on the capacity of soil heavy metals was established.The preliminary assessment of the Daxia River Basin heavy metal pollution and the current level of pollution.The average content of five heavy metal elements in the Xiahe River Basin is in the order of Cr>Cu>As>Pb>Cd.The results showed that the annual pollution capacity of five heavy metals Pb,Cr,Cd,As and Cu in the Xiahe River Basin was 6.4099t/a,25.6762t/a,4.8257t/a,5.9850t/a,43.7648t/a,they are positive.Indicating that the major river basin soil heavy metals and no excessive.In the presence of uncertain information,the deterministic model is difficult to solve such problems.In this paper,from the perspective of the existence of a variety of uncertainties in the river basin environment system,the river pollutant capacity estimation model based on blind information theory is used to evaluate the evaluation.The model calculates the confidence value of each interval and the pollutant capacity of each heavy metal in the river basin by calculating the possible range of the pollutant capacity of the river soil,and carries out the comprehensive evaluation of the heavy metal pollution capacity of the river basin.The results show that the soil heavy metal pollution in the Daxia River Basin is generally strong.9 rivers have a strong ability to accept the sewage,six rivers with strong capacity to accept the sewage,a river is in the sewage capacity.The comprehensive evaluation model of soil heavy metal pollution capacity and the regional cumulative index evaluation model were used to evaluate the heavy metals in the whole river basin.The results show that the comprehensive evaluation model can express the distribution of heavy metal pollution in the watershed.This provides a theoretical basis for the prevention and control of heavy metal pollution in small and medium-sized watershed.