Soil Geochemical Survey And Evaluation In Donglai Area,Inner Mongolia

Soil is the main carrier of agricultural production.The quality of soil directly affects the output of crops and the quality of agricultural products,which has an important impact on human life activities.In recent years,the situation of heavy metal pollution in soil has become increasingly prominent.Based on 468 surface soil samples collected in the east of Inner Mongolia,through the statistical analysis and correlation analysis of geochemical data and the determination of the baseline value of environmental geochemistry in the study area,the methods of single factor index,Nemero comprehensive index,land accumulation index and potential ecological risk index are used in this study The soil quality of the study area was evaluated.The spatial distribution law of eight heavy metal elements and the causes of the high value area of heavy metal elements were studied.Finally,the spatial distribution characteristics of abnormal elements in the evaluation results were studied.The results showed that:(1)The soil in Donglai area belongs to alkaline soil,the p H changes between7.58-9.58,and the average value of p H is 8.344.The average contents of Cr,Ni,Cu,Zn,Pb,as,Hg and Cd in the study area are 56.609mg/kg,25.783mg/kg,21.691mg/kg,62.425mg/kg,17.868mg/kg,9.373mg/kg,0.02mg/kg and 0.143 mg / kg,which are higher than the soil background value of the study area but lower than the national standard value,indicating that the content of heavy metals in some areas of the study area is relatively high,which may be related to human production activities A certain relationship.(2)Single factor index method,Nemero comprehensive index method,land accumulation index method and potential ecological risk index were used to evaluate the soil heavy metals in the study area.The results showed that the soil in the east of Inner Mongolia was not polluted by heavy metals,the land quality was good,and it was suitable for agricultural production activities.The content of individual heavy metals in some areas was high,so the prevention,control and modification should be done well in advance(3)There are some differences between the evaluation results with geochemical baseline value as reference value and the evaluation results with soil background value asreference value alone.Therefore,in the evaluation of soil heavy metal pollution,it is necessary to combine the geochemical baseline value to give more reasonable and correct results reflecting the soil pollution in the study area.(4)The spatial distribution of eight heavy metal elements showed that the risk area was distributed in a belt from northwest to Southeast near the three tribes,industrial and rural areas,Qinghe Village,Donglai town and Dongfa village.The soil risk area is mainly formed by river geological process,which is a natural cause.The abnormal elements in the evaluation results of land accumulation index method and potential ecological risk index method are distributed sporadically in space,and it is inferred that they are related to the passing railway and highway.