城市土地利用变化对生态系统服务的影响——以淮北市为例

Abstract

City is a kind of social-economic-natural complex ecological systems.Urban ecological land is an important component of urban ecosystem,which plays a key role to guarantee urban social-economy sustainable development,provide urban ecosystem services and improve residents′ quality.The rapid spread of urban area and intensive human activities have significantly changed the urban land use structure and ecological land quantity,thus seriously impacted the urban ecological service and human living environment.However,little information was available on the influence of urban land structure on ecosystem services in resource-exhausted cities.Through the remote sensing,GIS technology and evaluation method of ecological service value,the variations of land use structure and ecological service value were assessed in a typical resource-exhausted city—huaibei during 1987 to 2007 in this study.The results showed that from1987 to 2007,the total area and structure of ecological land in this city were drastically changed,with the proportion of ecological land area decreased from 91.45% to 71.86%.From 1987 to 2000,the area of farmland substantially reduced,but the areas of forest,water and built-up lands increased.While from 2000 to 2007,the area of farmland increased but the area of forest and water significantly reduced.Although there were no obvious changes of total areas of the built-up land in this period,the aggregation level of the built-up land increased significantly.However,the comprehensive land use dynamic degree of huaibei city has a decreasing tendency from 1987 to 2007,which reflecting the gentle land circulation during this period.Moreover,in these 20 years,urban ecological service value increased between 1987 and 2000 then decreased since 2000.The maximum value of ecological service appeared in 2000,which was 31.32×108 yuan.During 2000 to 2007,the ecosystem services of waste treatment and water conservation function mainly provided by water and forest have the greatest contribution.The variation of ecological service value during 1987—2000 was mainly due to the impacts of coal mining,which occupied large area of cultivated land and made the surface area sinking into desolated beaches or depression,thus caused the significantly reduction of food production services.Meanwhile,the increasing of wetlands from sink area and woodland by ecological constructions such as returning farmland to forest and artificial afforestation made other ecosystem services obviously improved.From 2000 to 2007,the increasing urban expansion and population growth convert a large sum of ecological land to built-up area,resulting the decreasing of the ecosystem services values.In addition,the distribution of urban ecological land significantly influenced the spatial variability ecological service value.The higher service value areas were mainly distributed on the south part of huaibei city where farmland and forestland is relatively concentrated,while lower service value areas were mainly concentrated in the built-up area.Thus it can be seen that urban land use structure change greatly influenced ecological services,and the results can provide certain scientific basis to the optimization of the landscape pattern and reasonable control of urban land in the huaibei city.