Platform Technology For Assessment And Control Of Agricultural Utilization Risks Of Arable Soils Polluted With Heavy Metals

It is important for assessment and control to the heavy metal pollution of arable soil in mining area to design the platform(RAPAPS) for assessment and control of agricultural utilization risks of arable soils polluted with heavy metals based on the GIS and professional theory of environmental science. This paper mainly includes the following content:(1)To establish the improved assessment model for the arable soils polluted with heavy metals in mining areas and to apply this model in RAPAPS. To evaluate heavy metal pollution of the soils in the Hengyang study area using this model and RAPAPS. The results showed that the situation of comprehensive pollution in the arable soils was serious. Of141samples evaluated, the number of samples that were clean and mild pollution was0, the number of samples that were moderate pollution was3, and the number of samples that were severe pollution was138.(2) To research and choose the existed spatial interpolation models, to select the Kriging spatial interpolation model that was used frequently in current research, to combine the Kriging spatial interpolation model with RAPAPS, the interpolation prediction of heavy metal pollution in the arable soils of the study area was realized based on components Geographic Information System.(3) To analyze the existed mainstream database technology, and to select Access database that was applied generally and function various. The existing attribute data and spatial data were sorted, and the attribute database for soils was established. ArcSDE was used in the platform RAPAPS as spatial database engine. The Access database was used as storage medium and combined with the Personal Geodatabase, which resulted in realizing unity of the spatial data and attribute data.(4) To make use of the control method that came from research group of the project for arable soil heavy metal pollution, and realize the control function for arable soil heavy metal pollution of the platform RAPAPS with the help of computer language. (5) To verify the practicability of the platform RAPAPS, and evaluate the heavy metal pollution with sampling point in the soil of Hengyang area, compared the traditional assessment models and methods with the improved assessment model in this paper. Two verification areas of the rice and vegetable fields in Hengyang and Chenzhou were chosen separately. In the four verification areas, the spatial interpolation prediction for soil pollution and the control methods were put forward, the control results were given, and practicability of the platform RAPAPS was verified based on the way that compare measured values in verification zone with the predicted values from the platform.The main conclusions of the paper were as follows:(1) The verification result of the improved assessment model showed that the assessment results of improved assessment model were more sensitive than the other assessment methods that were not considering the weights of assessment index.(2) The verification result of prediction function for spatial interpolation for the four verification areas indicated that difference rates of Pb were17.6%,198.7%,-6.5%,-1.1%. The difference rates of Cd were12.3%,158.03%,136.4%,41.2%. The difference rates of Cu were7.3%,388.2%,0.2%,-13%. The difference rates of Zn were3.2%,140.4%,-7.6%,3.8%. The paired T-test results of predicted values and measured values showed that P values were all greater than0.05, the difference was not significant.(3) The verification results of the control function for soil heavy metal pollution for the four verification areas showed that difference rates of Pb were4.8%,-7.6%,13.6%,-1.8%. The difference rates of the Cd were-19.8%,5.3%,-9.4%,-5.2%. The difference rates of Cu were-14.5%,15.5%,-10.0%,-2.9%. The difference rates of Zn were-15.2%,-6.2%,-16.3%,-5.7%. The paired T-test results of predicted values and measured values showed that P values were all greater than0.05, the difference was not significant.(4) RAPAPS platform worked well on the whole, which could achieve the function of geographic information system. In addition, the functions were verified for pollution assessment and pollution control, and showed a good practicability. So the platform RAPAPS could be applied for the risk assessment and control of heavy metal pollution in arable soils of mining areas.