和田绿洲生态系统服务价值评估

摘要

[目的]评估和田绿洲的生态系统服务价值.[方法]在目视解译4期20景遥感影像并对2期土地利用数据进行重新归类基础上,计算各类生态系统服务价值.[结果]1980-2010年,研究区生态系统服务总价值增加30.44×108元,增加了16.51％.生态系统服务价值上升的主要原因是其南部山区雪冰面积因年降水量增加而增加.草地对研究区生态系统服务总价值贡献率呈下降趋势,其原因是草地退化及耕地对草地侵占.就流域角度而言,上游区生态系统服务价值增加导致研究区生态服务价值上升.中游区与下游区生态系统服务价值均减少.其中,中游区湿地(-1.83×108元)、水域(-1.68×108元)、森林(-0.86×108元)及草地(-0.80×108元)等服务价值减少是其主要原因；下游区水域(-0.61×108元)、草地(-0.24×108元)及森林面积(-0.07×108元)等生态服务价值减少是其根源.[结论]进一步采取退耕还林(还草)、严禁开荒等政策,西北干旱区森林、草地等生态系统退化趋势是可以遏制和逆转的.%The study aimed to assess the ecosystem services value in Hotan Oasis,Xingjiang.[Method] The visual interpretation method was adopted to process TM/ETM+ images based on field investigation in Hotan Oasis.These interpretation data,along with two periods of land use data,were reclassified to farmland,forest,grassland and so on.Then,the ecosystem services value was calculated and analyzed.[Result] Analysis indicated that the ecosystem services value had been increased by 30.44×108 Yuan (16.51％) in the study area during 1980-2010,which can be explained by the increase of glacier and snowfield distributed in the south mountain with the increase of annual precipitation.At the same time,the contribution rate of grassland to ecosystem services value had been decreased as a result of degradation of grassland and occupation from farmland.For the whole basin,the increase of ecosystem services value came from the upper reaches,while the ecosystem services value had been reduced in the middle and lower reaches.In the middle reaches,the reduction came mainly from wetland (-1.83×108 Yuan),waters (-1.68×108 Yuan),forest (-0.86×108 Yuan) and grassland (-0.80×108 Yuan).But in the lower reaches,the ecosystem services values of waters,grassland and forest were-0.61 ×108 Yuan,-0.24×108 Yuan,and-0.07×108 Yuan,respectively.[Conclusion] If some effective policies,such as the implementation of returning farmland to forest and ceasing from farming to grazing,would be taken,the ecosystem degradation can be constrained and reversed in the northwest arid region.