重庆市巫山县土地利用格局及其生态系统服务价值的时空变化

Land use pattern and the spatial-temporal variability of ecosystem service value in Wushan County,Chongqing

巫山县位于重庆市东部,地处三峡库区腹心,属于长江中上游重要的生态屏障区,也是实施河长制的重点区域,生态保护的意义重大。因此以巫山县为研究区域,基于1990—2015年间的六期遥感影像,利用遥感与地理信息技术,分别从时间和空间两个尺度分析土地利用类型的结构变化,并对巫山县生态用地所提供的生态系统服务价值进行评估。在此基础上采用GeoDa软件分析了土地利用类型斑块面积与生态系统服务价值之间的空间相关性。结果表明:(1)2000—2015年间的土地利用综合动态度指数最高,林地呈现出下降的趋势,耕地、草地、水域以及建筑用地的面积均有不同程度的增加,其中单一类型动态度最大的是建筑用地;(2)巫山县25年间的生态系统服务价值共增加了338.97×10~6元,生态系统服务主要为调节服务,其次是支持服务,水资源供给、水文调节以及净化环境等生态系统服务改善较大;(3)生态系统服务价值与土地斑块面积之间的空间相关性以高-低和高-高类型区为主,其中高-高类型区集中分布着林地,表明林地斑块面积与生态系统服务价值之间呈现出正相关关系。

Wushan County is located in the hinterland of the Three Gorges reservoir in the east of Chongqing,and it belongs to the important ecological barrier zone in upper and middle reaches of the Yangtze river;it is also a vital area for the implementation of River Governor system,so the ecological protection is of great significance for regional development and policy implementation.This article takes Wushan County as the research object.Based on the six periods of remote sensing images during 1990-2015,then with the help of remote sensing and geographic information technology,we analyzed the structure changes of land use types from time and space scales,respectively.On the basis of this,the evaluation of ecosystem service value provided by ecological land in the study area is carried out.Then with the help of GeoDa software,the spatial correlation between patch area and ecosystem service value change is analyzed.The results are as follows.(1)Between 2000-2015,the land use comprehensive dynamic degree index was the highest,and the forestland showed a downward trend.The area of farmland,grassland,water area and building land increased from varying degrees,and the building land single type dynamic degree index was the largest.(2)The value of ecosystem services in Wushan County increased by 338.97×10^6 yuan in the past 25 years.Ecosystem services were mainly for regulation services,followed by support services.The water resources supply,the hydrological regulation and the purification of the environment were improved greatly.(3)The spatial correlation between the patch area and ecosystem service value was mainly showed in high-low and high-high types regions,and the high-high type regions were mainly distributed with forest land,indicating that there was a positive correlation between forest land patch area and ecosystem services value.