基于RS和GIS的中心城区土地利用变化及生态系统服务价值分析——以衡阳市为例

Analysis of Land Use Change and Ecosystem Service Value in Urban Central Areas Based on RS and GIS——Taking Hengyang City as an Example

为了明确城市中心城区土地利用变化对区域内生态系统服务价值的影响。以衡阳市中心城区为研究区域,结合RS和GIS分析2000—2010年土地利用变化特征,在此基础上采用单位面积价值当量因子对中心城区的生态系统服务价值(ESV)变化进行测算,并运用马尔科夫模型预测了在历史趋势发展情景下2030年衡阳市中心城区土地利用及生态系统服务价值变化情况。结果表明:①衡阳市中心城区土地利用以耕地、林地、水域和建设用地为主,2000—2010年耕地、林地、草地和未利用地面积呈下降趋势,建设用地和水域面积呈增加趋势;各土地利用类型在数量和空间上转换显著。②研究期内生态系统服务价值呈下降趋势,2000—2010年衡阳市中心城区生态系统服务价值由24.59亿元下降到23.65亿元,水域和林地为对中心城区生态系统服务价值贡献最大的地类。③根据马尔科夫模型的预测结果,2030年衡阳市中心城区耕地和林地会大幅减少,建设用地会大幅增加。衡阳市中心城区除水域生态服务价值呈上升趋势外,其他用地生态价值均呈下降趋势,总的生态系统服务价值也将继续呈下降态势。在新型的城镇化扩张中,需要慎重权衡城市发展与生态保护的关系。

In order to clarify the impact of land use change in urban central areas on the value of ecological services.Taking the central areas of Hengyang city as the research area,combining RS and GIS to analyze the characteristics of land use change from 2000 to 2010,using the value equivalent factor method to measure the changes of ecosystem service value(ESV),then using the Markov model to predict the ecological service values of various land types in the central areas of Hengyang City under the historical trend development scenario.The results showed that:First,the land use in the urban central areas of Hengyang City is dominated by cultivated land,forest land,water area and construction land.The area of cultivated land,forest land,grassland and unused land is reducing,however the area of construction land and water area is increasing.The type of land use has changed significantly in quantity and space from 2000 to 2010.Second,the value of ecological services showed a downward trend during the study period.From 2000 to 2010,the value of ecological services dropped from 24.59×10^8 yuan to 23.65×10^8 yuan.The value of ecological services in waters and forests play important roles in the total ecological service value of the urban central area.Third,the results of Markov model suggested that the cultivated land and forest land will be greatly reduced.The ecological value of water resources will increase,however the ecological value of other land uses will decrease,the value of total ecosystem services will still continue to decline in 2030.We need to carefully weigh the relationship between urban development and ecological protection in the future.