The Landscape Pattern Optimization Of Jinan City Based On The Ecological Constraint Conditions

With the rapid development of regional economy, the process of urbanization is speeding up, but a series of ecological and environmental problems are appearing, such as environmental deterioration, land degradation, global climate change, biodiversity reduction of the social economy and the ecological problems at landscape and regional levels. The regional ecological security is being confronted with danger. The landscape pattern is the comprehensive performance of the landscape heterogeneity, and the results of nature, society and human effect. The spatial distribution characteristics of landscape pattern nearly connect with the regional security; the landscape pattern optimization could increase the diversity and stability of landscape and keep the regional sustainable development and security. So this paper researches the landscape pattern optimization based on the ecological constraint conditions.The research of landscape pattern optimization solves the rational land utilization by the theory of landscape ecology, which is the optimized combination of the original landscape elements or the introduction of the new elements, and the regulation or construction of the new landscape pattern. The paper improved on the key issues of the landscape pattern optimization, synthetically considered the natural and societal constraint conditions, constructed the ecological constraint model based on the theoretical definition of the ecological constraint conditions, and combined the model with the spatial simulation technology. This paper's aim is to solve the quantity and space optimization of the landscape pattern.This paper takes the Jinan city of the eastern urbanized area as the study area, and researches the landscape pattern optimization based on the ecological constraint conditions. The main research contents and results follow:(1) The meanings of the ecological constraint conditions of landscape pattern optimization were defined. Under the guidance of the sustainable development, it analyzed the meanings of the ecological security evaluation, the ecosystem services assessment, the ecosystem health evaluation and the ecological risk assessment, and ascertained their logical relation, which provided the theoretical basis for the definition of the ecological constraint conditions.(2) This paper analyzed the present situation and evolution of the landscape pattern and the ecological service function. The landscape pattern concludes two parts, the one is the quantitative distribution, and the other is the spatial allocation. So this chapter analyzed the landscape pattern from quantity to space and from static state to dynamic state. Then it analyzed the ecological change of the different landscape types by the evaluation method of the ecosystem service value, on this basis, analyzed the evolution mechanism of the landscape pattern. As the part of status analysis, this content is the basis of the landscape pattern optimization research.(3) This paper researched the landscape pattern optimization based on the ecological constraint conditions, namely the fourth chapter and the fifth chapter. The fourth chapter is the quantity optimization based on the ecological constraint conditions, which constructed ecological constraint conditions from six facets and one objective function by the grey linear programming. It came to the different optimization projects of the total quantity control by the simplex method, and chose the optimum one through comparative analysis. At last it confirmed the quantity allocation of the different landscape types. The fifth chapter is the spatial optimization of the landscape pattern based on the ecological constraint conditions, which applied genetic algorithm to research the spatial structure optimization of the landscape pattern and decided the spatial distribution of the different landscape types.(4) The result indicated that compared to the current status of the landscape pattern, the area of the cultivated land decreased, the area of woodland (including garden plot) increased, the area of the urban land increased, and the area of the rural residential land decreased, which accorded with the policy of the conversion of cultivated land to woodland and grassland and the intensive utilization of the rural residential land, so the research area could obtain the upper ecological benefit. The genetic algorithm has stronger function of random search, and the search process is flexible, so the result of spatial optimization is ideal. So this method can express the ecological factors in the model which mainly influenced on the landscape pattern change. On one hand, the result of landscape pattern optimization can reflect the actual state of the landscape change. On the other hand, it provides the optimum pattern for the regional landscape management and promotes the regional sustainable development.