Study On Ecological Risk Assessment Of Farmland Conversion In Shaanxi Province

Since reform and opening up， along with economic growth and urbanization levelimprovement. A lot of farmland from agricultural sector transfers to other sectors. On the onehand， farmland conversion delivers precious land element. On the other hand， farmlandconersion has an bad affect on the environment. Farmlad conversion also brings negativeexternalities and reduce the ecosystem service function. Because of the negative externalityproblems， marginal social cost is bigger than marginal private cost. Market mechanism isdifficult to have an effect on negative exteralities，this part of cost is difficult to make up andrecord to the GDP. Farmland is one of most valuable natural resources and is hard to changeits usage， we should be more careful to change farmland uses. We need banlance betweenreducing risk costs and the ecological risk of farmland conversion. Ecological risk assessmentof farmland conversion provides strong guarantee for the sustainable development andimportant basis of risk management.On the basis of analysis the situation of farmland conversion in Shaanxi province andguanzhong region， shanbei region and shannan region， analyse the risk source， riskreceptor and ecological endpoint of farmland conversion in Shaanxi province and guanzhongregion， shanbei region and shannan region. Build ecological risk assessment indicatorsystem for farmland conversion， divide the ecological risk into5grades. Use analytichierarchy process(AHP) and fuzzy comprehensive evaluation method for emprical analysis.According to the study， farmland conversion is mainly cultivated land conversion inShaanxi province， then garden land conversion， and other types of farmland conversionaccounts for only a small part. There are great differences dring guanzhong region， shanbeiregion and shannan region. Farmland conversion in guanzhong region accounts for65.79%offarmland conversion in Shaanxi province. Different types of farmland conversion havedifferences， cultivated conversion and garden plot conversion in guanzhong area is theprovince’s72.8%and91.9%， forest land conversion and grass land conversion in sahnbeiarea is the province’s61.66%and89.91%. The situation of farmland conversion is differentin different areas， farmland conversion of guanzhong area and shannan area mainly comesfrom cultivated land， the farmland conversion of shanbei area comes from forest land conversion. Ecological risk in Shaanxi province caused by farmland conversionis in mediumlevel. Farmland conversion in shannan area caused ecological risk is in low level. Farmlandconversion in shanbei area and guanzhong area caused ecological risk is in high level.Through the analysis found that， shanbei and guanzhong’s ecological risk level are at ahigher level， and there are different resons. As most of the land conversion occurs in theguanzhong area， farmland conversion area is lager， the ecological risk is greater. Shanbeihas a fragile ecological envirenment， farmland conversion causes a serious consequencethan other areas， and ecological risk is more bigger. Shannan has a good ecologicalenvirenment and farmland conversion area is lesser， ecological risk in shanbei area casuedby farmland conversion is lesser.