The Landscape Ecological Research On Spatial Patterns Evaluation And Optimization In Fast Urbanizing Areas

The urbanization has already become the world trend. In 2001, the urbanization level of the world was up to 47%, and it was about 37% in China. According to the rule of development of the urbanization, in future 50 years, our country will go through a fast urbanization course, about 300 million - 400 million people will transfer from the countryside to the cities and towns, and the speed of the urbanization is unprecedented. With the arrival of the urbanization, the ecological problems of cities of our country will be more outstanding, not only generally characterized with "urban disease", but also the regional environmental and ecological problems that cities' development cause will be serious day by day.The sustainable development of the urban must regard sustainable development of the environment as the prerequisite and guarantee. The main study range of Landscape Ecology is the spatial pattern, ecological course and the interaction as well, and its principles offer theory frame in the practice of optimizing spatial pattern and raising function and stability of ecosystem. In the case study of Yiwu city in this thesis, we divided the downtown area into 7 ecological landscapes types. They were habitat landscape, trade and business landscape, public utility landscape, industrial landscape, roads and squares landscape, green land landscape, water areas and other landscapes, etc.; Considering the spot survey, we dealt with the ikonos aviation remote sensing image scaling 1: 10000 and the land use plot of Yiwu in 2001 by the GIS software MapInfo5.0. Then we summed those parameters such as quantities, area and perimeter, etc. of the landscape patches. We imported the parameters into the software of Excel 2000 for calculating 10 landscape pattern indexes. In such a way, we carried out a quantitative landscape evaluation of Yiwu downtown.The results showed that the spatial pattern of Yiwu urban landscape had many problems such as unreasonable distribution, decreased types of natural landscape, single structure and function of landscape, increased fragmentation etc.. In every landscape type in 2001, the large percentages of area were habitat landscape and industrial landscape, which was 36.8% and 20.1% respectively, the proportions of green land landscape and water areas landscape were partial and small, was 4.8% and 2.7% respectively; The number of landscape patch and diversity index of habitation was the highest and the fragmentation index of green land landscape was the lowest in all landscape types. And the driving forces of the formation of the current pattern included expansion of population, the development of economy and technology, the faultiness of policy and system etc.. The factors reflected that the human urban activity had severe interference to the landscape pattern.According to various landscapes type function and the characteristic, we further proposed the tentative plan to the overall landscape pattern optimization of Yiwu. We classified the 7 landscape types into 3 different levels: the urban development space, the natural ecology space and the landscape ecology corridors. The urban development space had great function on economic production, social activities and culture support, which included habitat landscape, trade and business landscape, public utility landscape,...