近20年渭干河流域土地利用与生态系统服务价值时空变化

Temporal and spatial dynamic changes of land use and ecosystem service value in the Weigan River Basin in recent 20 years

基于遥感与GIS技术,选择地处天山山脉中段南麓塔里木盆地北部的渭干河流域为研究区,以新疆1990、2000、2008年遥感影像和地面实测数据为主要数据源,利用GIS空间分析、数学统计分析方法提取渭干河流域近20年各种土地利用类型的面积变化、净变化速度等动态变化信息;在总结生态系统服务价值国内外研究进展的基础上,参照谢高地等人的中国陆地生态系统单位面积服务价值系数和Costanza等的生态系统服务价值计算公式,结合当地粮食产量和粮食平均收购价格,分析渭干河流域生态服务价值的时空变化特征,揭示渭干河流域生态系统服务价值和时空分布的不平衡状态。结果如下:(1)草地和未利用地所占比重超过70%,其他土地利用类型所占比重不到20%,各种土地利用类型分布和面积变化存在时空差异。(2)1990—2008年研究区的生态系统服务价值总量减少了59 633万元,其主要原因是草地、林地和沼泽面积的减少。流域生态系统服务价值结构变化较大,其提供的支持服务功能最强,供给服务功能相对较弱。(3)下游的单位面积生态系统服务价值大于中上游地区,研究期内流域中、下游生态系统服务价值减少较大,上游地区的生态系统服务价值略有增加。

Based on GIS-RS techniques,by using the data of land use in Xinjiang during 1990 to 2008 which were extracted from remote sensing images by means of spatial analyst,and taking the Weigan River Basin located at the south foothill of middle Tianshan Mountains and the northern part of Tarim Basin as the study region,the area change and net change rate of various land use types in recent 20a were analyzed.By adopting the service value coefficients of Chinese terrestrial ecosystems proposed by Xie Gao-di,and the calculation formula of ecosystem service value proposed by Costanza,in combination with the local grain yield and grain purchasing price,the temporal and spatial dynamic changes of ecosystem service value in Weigan River Basin were studied,so as to reveal the imbalance situation in the spatial and temporal distribution of ecosystem service value in Weigan River Basin,and to provide scientific basis for land use planning and decision making.The results show that：（1） The grassland and unused land covered more than 70%,and the other land use types covered less than 20% in Weigan River Basin.There were spatial and temporal differences in the area distribution and change of various land use types.（2） During 1990 to 2008,the total value of ecosystem services in the study region was reduced by 596.33 million yuan.The main reason for the reduction was the area decrease of forest,marsh and grassland.The structure of ecosystem service values changed greatly and its function of supporting services was the strongest,while its function of supplying services was relatively low.（3） The value of ecosystem services per unit area in the downstream was more than that in the upstream and midstream.During 1990 to 2008,the value of ecosystem services in the midstream and downstream reduced remarkably,while that of the upstream increased slightly.