Evaluation Of The Effect And The Implementation Process Of Restoration In Heavy Metal Polluted Farmland In Xiangtan City

With the accelerating process of industrialization,heavy metal pollution problems in farmland is becoming increa singly serious,which become a serious threat to national food security,ecological security and people’s health and safety.One of the important tasks of environmental protection and control in our country is to carry out effective repair management in heavy metal pollution of farmland.Therefore,from the strategic height of sustainable developm ent of the CPC central committee and the state council laun ched a series of soil environmental protection and management of major decisions,but is needed objetive evaluation whether those decisions achieve the desired effect.Xiangtan city in hunan province is an important grainproducing area in southern China,but the farmland of heavy metal pollution is serious.Therefore,a there years of repairing of heavy metal polluted farmland is conducted in Xiangtan city,and a filed survey and scientific analysis is needed to evaluate the effect especially evaluate if the measures are in place.in the process of implementation.In order to achieve scientific evaluation results,this paper used the theory of system theory,ecological systemand service theory,the evaluation theory of project management,this case adopted the literature query,data collecti on,mathematical statistics,the combination of model build ing method,to analyze the strengths,weaknesses,opportunitie and threats of restoration implementation process in XiangT an heavy metal polluted farmland with SWOT analysis method.On the basis of farmland resource and the characteristics of the project to build the restoration effect evaluation system of heavy metal polluted farmland in Xiangtan city.Based on the SPSS analysis tools to analyze the correlation between implementation process and the soil cadmium reduce rate.The analysis results are as follows:(1)Applying the SWOT analysis method to classify the imp act factors as strengths,weaknesses,opportunities and thr eats and researching the effect of various factors.Based on Delphi method to assign points,the influence degree of each factor to calculate its overall strength.On the basis of development strategy of quadrilateral is constructed.This part made conclusion as follows: ?This project in the proc ess of technology implement exsited prominent disadvantages,lacked of advantages,more opportunities than threats,exces s impact of sorting is the opportunity >disadvantages >advantage >threats;?The increase of technology impelment rate in heavy metal polluted farmland of Xiangtan city sho uld be used with WO strategy,take advantage of the opportunity to reverse their own disadvantage;?The main reason o fthe technology implement rate increasing in 2014 to 2016 i sthat strong financial and policy support,improving methods and optimization of implementation of the main structure of technology application,to further improve the technique implement rate is to solve the backward agricultural infras tructure,complex terrain conditions,key problems such as poor land circulation mechanism.(2)This paper selects implementation effect evaluation indicators from four aspects such as technical effect,ecol ogical benefits,social benefits and economic benefits to constructe the heavy metal polluted farmland restoration ev aluation system in Xiangtan city.The system was divided into 3 level,scontaining the total goal layer(1 indicator),indicator layer of level one contained 4 indicators,the layer of level two contained 13 indicators.For the evaluatio nmethods,this paper takes Analytic Hierarchy Process to identify the weight of all the indicators,and evaluationvalue of indicators are obtained by normalization after got the actual value of these indicators,envntually using the weighted arithmetic average method to proceed the sum by layers,got the comprehensive score,achieve the implementati on effect of this project.The analysis results showed that:The overall status of this project is qualified,which has large improvement than before.In this project,technical effect is remarkable,the economic benefits of the project is the second,ecological benefit,social benefit have different degrees of improvement.(3)Using SPSS analysis tools,analyzed the correlation and linear regression ralationship between the technology i mplement rate and soil cadmium reduction rate: there is a s trong positive correlation between the technology implement rate and the soil cadmium reduction rate.And there is a sig nificant linear regression relationship between the two factors.The technology implement rate is the independent vari able,while the soil cadmium reduction rate is the dependent variable.The formal to the latter has more significant expl anatory power,that is to say the probability is higher whe n soil cadmium reduction rate changes over the technology i mplement rate.