城市土地利用变化对生态系统服务的影响——以淮北市为例

城市是一类以人类活动为中心的社会-经济-自然复合生态系统.城市的快速蔓延及强烈的人类活动显著地改变了城市的土地利用结构,进而严重影响了城市生态系统服务及人居环境.通过遥感、GIS技术及生态系统服务价值评估等方法,对淮北市1987年、2000年和2007年3个时期20a间的土地利用结构及生态系统服务价值的演变进行定量评价.研究结果表明:1987-2007年间淮北市生态用地空间结构和面积发生剧烈变化,生态用地占城市面积的比例由91.45％降低至71.86％.1987-2000年,农田面积大幅度下降,而林地和水体都呈不同程度的增加趋势,建设用地面积增长迅速.2000-2007年,农田面积有所增加,林地和水体面积却明显下降,建设用地总面积虽然没有明显变化,但其聚集度显著增加.20年间,城市生态服务功能的价值呈现先增加后减少的趋势,在2000年达31.32亿元.2000-2007年,以废物处理和水源涵养功能退化最为严重.可见,城市土地利用结构的变化与生态服务功能密切相关,此结果可为淮北市景观格局优化及土地合理调控和管理提供一定的科学依据.

Effects of land use change on ecosystem service value: a case study in Huaibei City, China

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.