基于梯度分析的武汉市生态系统服务价值时空分异特征

以2000年和2010年覆盖武汉市域的6景Landsat TM/ETM+遥感影像为基础数据,运用最大似然分类法提取土地利用类型,结合计算的武汉市单位面积生态系统服务价值,得到栅格尺度的武汉市生态系统服务价值分布图,并引入梯度分析方法,以城市中心为原点设置梯次环及考虑城市发展轴线设置采样条带,选取生态系统服务价值变化量和变化率两项指标进行梯度分析。结果表明,2000—2010武汉市总的生态系统服务价值共减少了2.68亿元;梯次环分析发现,武汉距离城市中心12—30km的北3—5环,以及距离市中心12—24km的南3—4环生态系统服务价值下降最为显著,而北8环及南7环则上升最为明显;条带分析发现,在东西向条带上,生态系统服务价值变化率曲线图呈现出一个对称的"W"形,而在南北方向上,变化率曲线可以按照变化的幅度分成了4个部分,此外与梯次环变化率曲线规律一致的是,北部要比南部变化更为剧烈。

Spatiotemporal variation of ecosystem services value based on gradient analysis in Wuhan:2000-2010

Ecosystems provide a multitude of services that are fundamental to the well-being, livelihood, health, and survival of humans. A comprehensive understanding of the spatiotemporal features of Ecosystem Services Value (ESV) is necessary for appropriate land use and land management in metropolitan areas. Based on this research, methods of quantitative analysis could be considerably improved. Considering Wuhan as an example, we classified Landsat TM/ETM+ images into developed land, unused land, arable land, garden plots, forests, and water by using a maximum likelihood analysis, and calculated the ESV per unit area. Based on spatial distributional maps of ESV, we introduced a gradient analysis and set gradient circles and belt transects to analyze the spatiotemporal features of ESV. The main conclusions were 1) the amount of ESV decreased by 268 million RMB from 2000 to 2010; 2) based on the gradient circles analysis, ESV decreased within the north 3^rd to 5^th ring road (corresponding to 12-30 km from the urban center) and south 3^rd to 4^th ring road (corresponding to 12-24 km from the urban center), whereas ESV increased within the north 8^th ring and south 7^th ring;3) based on the belt transects analysis, the change rate of ESV showed a symmetrical W-shape pattern latitudinally, whereas longitudinally, it was partitioned into four sections based on theamplitude of the ESV change rate. Overall, northern Wuhan demonstrated more changeability in ESV than the southern area.