Study On Eco-Environmental Sustainable Development In County Based On Ecological Carrying Capacity

The ecological environment is the fundament of mankind subsistence and soci-economicgrowth. The problem of ecological environment deteriorating has become the global problemsince 20th century, which threatens mankind exist and development, and forced people tothink what way the society and economy should take in the future. Sustainable development(SD) was put forward and agreed by all people under this background. Now the hot point ishow to use the theory of SD to prevent the problem of ecological deteriorating. The realmeaning of SD should be developing both in soci-economic system and in ecological system.The Ecological Carrying Capacity (ECC) is the very kind of such quantitative measuringindex to preserve the steady of eco-system, limit people action under the eco 一 systemsupport threshold. And it can be used as a very important criterion of judging whether theregional development is sustainable or not. Using ecological carrying capacity theory tostudy the sustainable interrelationship among region resource, ecological environment,increasing of population and social economy, is one of the focus in ecological, geographicaland economic research nowadays. The application of some new ration research methods,such as RS and GIS, is more and more commonly in the studies of ecological carryingcapacity.Zhenlai county lies in Ecotone between Agriculture and Animal Husbandry inNortheastern China, where is a weak area in self-adjustment, restore and withstand thepressure from outside. Recent years, the environmtal problems become more and moresevere with the development of population, society, economy and aridity of climate, forexample, the structure of eco-system is unreasonable and the function become weak, naturaldisaster happen frequently, , especially drought aggravating the development of thesalinization of soil of the land and meadows degradatetion. The development of humansociety has badly disturbed the balance of eco-system. According to the above, the paperchooses this county as the object to study.Land use and land cover is the most outstanding sign of landscape in the surface of theearth, whose change is the common result of coactions of nature and mankind. We explainAmerican TM Satellite dates of 1989,1996 and 2001 for Zhenlai county Jilin by means ofRS-GIS integrative technique, and pick out the information for the study of ecologicalcarrying capacity. The result shows that the main landtype of Zhenlai appears "two increasesand three decrease" in quantity. "two increase"means cultivated land and salt and alkalineland increase, "three decrease"means the area of meadow, water and wetland(wetlanddecease very fast) decrease rapidly. There is an obviously mutual transformation among saltand alkaline land, meadow, wetland, water and cultivated land from the angle of distribution,for example, most of the increased land is transformed from meadow, water and wetland, andthe new cultivated land is from the meadow. The structure of land use has a really bad effectto the enviormont.According to the meaning of ecological carrying capacity, and the devilment level ofenvironment, society and economy, we established an index system for ecological carryingcapacity evaluation, which was compsed with ecosystem flexibility, resources andenvironment carrying capacity and social influence, and it totals to 18 indexes. Based on theindex system, the ecosystem carrying capacity was evaluated in 4 grades, which is ecosystemflexibility index, resources and environment carrying capacity, social influence and theintegrated ecosystem carrying capacity. And we chose and amend the Principle ComponentAnalysis (PCA) after contrast it with the other common methods. According to the results,the ecosystem flexibility, resources and environment carrying capacity and the integratedecosystem carrying capacity are decline all together, and the pressuer from social influclebecome strengthener. The grade of ecosystem flexibility index descended from "very steady"to "extremely unstable", and the grade of resources and environment carrying capacitydescended from "mid-tolerance"to "untolerability", and the grade of social influcle changefrom "support" to "mid-pressure", and the grade of ecologicial carrying capacity descendedfrom "common" to "extremly weak". According to the causation to decline of ecologicialcarrying capacity, we found that the primarry ones are irrationally exploiture and unculturedproduction management, secondly, the frail ecological environment is a advantage, thirdly,the deficient found of environmental protection and incomplete managing system can notprevent the decline of ecological carrying capacity.Based on the result of evaluation, the paper analyzed the position of sustainabledevelopment in Zhenlai. We class the sustainable development into 5 that is strongsustainable, mid-sustainable, weak sustainable, unsustainable, utmost unsustainable. Theresult shows, the grade of sustainable development of Zhenlai has descended from"mid-sustainable" in 1989 to "unsustainable" in 2001. Base on the result and consideringpracticability, we put forward proposals for region sustainable development from the angle ofmeadow, wetland, land and water resource ecological system, which can be a direction forthe development of society.