The Research On The Variation And Optimization Of Land Use Structure Of Wangcheng District In Changsha

In this paper, in order to strengthen the ecological protection and sustainable development as the duidance,construction of the ecological carrying capacity,ecological green equivalent and ecological support ability for multiple objective programming model and the establishment of the projection of the land use structure optimization scheme of grey correlation degree judgment, discussed the new method of land use structure optimization based on the ecological protection,changed the traditional pattern of land use in pursuit of the maximization of economic benefit,and provided new theory for the counties of the land use structure.The analysis results show that:1) In recent ten years, with the accelerating process of urbanization, the Wangcheng area has different land use types,construction land growth to accelerate significantly,totally increase5522.47hectares, with an average annual growth rate of3.45%while the forestry ecological land and agricultural land decreased significantly, totally reduce5114.02hectares in ten years, the annual average reduction rate is0.80%, the main driving factors is the development of city urbanization expansion.2) Introduction the entropy to analysis the land use diversity,the greater entropy is,the more complex of land density,the entropy values of every township in Wangcheng area changed in1.32-1.80,urban areas and the surrounding towns diversity index reached1.7,the land type of the township in Wangcheng area has high degree of uniformity,it has high diversity, low dominance, this township(town,such as Xingcheng and Gaolingtang etc),the urbanization degree is relatively higher,the economics are more developed,but serious environmental destruction.low,while the diversity index is relatively below1.5in remote Township, uneven distribution in different land use types, diversity index is low, land use has the rather higher degree of dominance.forest land accounted for a relatively high proporation,these towns (such as the town of Qiaoyi and Jingang etc) have low level of development economic,economic development is relatively backward,but the econogical environment is good.the main factors causing this situation is the construction land increased and economical land occupied in the process of urbanization and economic development,resulting the destruction of the economical environment3) Through the analysis of the city at the fieldwork and data, the main factors that restrict the land use in Wangcheng area are:the forest land is occupied by a large,and low quality cultivated land、urban construction land and rural construction land use extensive management,contradiction between protection of the ecological environment and economic development.4) In this paper, taking the ecological capacity, ecological green equivalent,ecological supporting capacity as the objective function of Wangcheng districtland use structure optimization model, Three objective functions are obtained by using the ecological footprint,ecological service value and benefit coefficient to achieve, by using DPS software, conclude five kinds of land use structure optimization program. By means of the grey relation projection method to optimize the land use structure, to obtain the optimal solution. From the optimization results, agricultural land in Wang cheng area reduces1236.88hm2, construction land increased1454.77hm2, other land area reduced217.89hm2,realize the ecological optimum but on the whole, the social efficiency and the economic benefit is improved.In this paper, taking Wangcheng area as an example, based on the ecological protection of the land use structure optimization, the results roughly in line with the actual, and provide strong evidence for the implementation of the relevant departments of policy system.