Abstract:

Land is an irreplaceable material basis and space vector for human survival and society development,which lays a solid foundation for the socioeconomic activities.All the human activities will inevitably reflect in the structure of land use,and at the same time the change of land use structure will,in turn，affect the development of natural conditions as well as its social and economy development.Recently,with the development of society and increase of population,the contraction between human and land is standing out gradually.The inappropriate use of land use has an increasingly negative impact on carbon cycle of landscape ecosystem,and it is also the main human activity,only second to the burn of fossil fuel,that leads to the sharp increase of carbon dioxide in the air,accounting for the global change and imbalance of carbon cycle.Therefore,from the aspect of ecological security,how to gain a greater comprehensive output and accomplish the maximization of economy benefits，social benefits as well as ecology benefits through a proper land use，structure is an important way to solve,at least mitigate,the great contraction among land use，economy development and ecology environment.The construction of optimized land use pattern that meets the ecological benefits is an effective way to protect the limited land resources and coordinate the contradiction between the socioeconomic development and ecoenvironment.Based on the land use and socioeconomic data of Wuhan Urban Agglomeration from 2002 to 2009,this study introduces two ecological indicators,i.e.soil organic carbon stocks and land use green equivalent,as the measurement of its ecological benefits under the current land use structure.And the model of TOPSIS (technique for order preference by similarity to ideal solution) is employed to evaluate the ecological rationality in each year.Then a multiobjective programming model of target year combining the maximization of economic and ecological benefits is built,and the Matlab optimization toolbox is utilized to compute the results,based on which an optimized quantitative land use structure that suits the development demands is constructed,presenting a quantitative pattern of “four increases(cultivated land,forest land,town industrial and mining land,transportation land),three minuses(other agricultural land,rural land and unused land) and three stability(garden land,grassland and other construction land)”.And through the evaluation of the ecological rationality by the TOPSIS model,the ecological benefits of target year reveals to be in a positive direction,realizing the maximization of comprehensive benefits and the balance of each land use type on the basis of the original advantage of each type.Finally,some tentative suggestions on sustainable land use are put forward,which would have some guiding significance and practical meanings on the virtuous circle of land use system and the creation of “Resourcesaving and environmentfriendly society”.Further studies in spatial pattern which takes micro factors such as field cultivation measures and regional disparity into consideration will be explored to better guide the management and function of land use policy