伊犁新垦区土地利用变化及其对生态系统服务价值的影响

Land Use Changes and Its Influences on Ecosystem Service Value over the Newly Reclaimed Area of Yili,Xinjiang

本文运用GIS和遥感技术,分析了1985年～2008年间,新疆伊犁河谷新垦区的土地利用变化情况,并利用Costanza提出的生态系统服务价值评估思路,分析了20多年来,新垦区由土地利用变化引起的生态系统服务价值在时间、空间和结构上的变化。结论如下:①1985年～2008年间,研究区耕地不断增加,但草地有退化为盐碱地或沙地的倾向;②研究区的生态系统服务价值减少了6.19%。在新垦区今后的农业开发中,一方面,应考虑生物多样性保护和水源涵养功能,防止过度开发引起的草场沙化、湖泊与湿地萎缩、土壤侵蚀加重及农田土壤盐渍化等生态问题。另一方面,应通过种植结构的优化和调整,提升整个区域的生态系统服务功能;③敏感性分析的结果表明,生态系统服务价值对生态价值系数的敏感性指数均小于1。这说明研究区内的生态系统服务价值缺乏弹性,基于谢高地价值系数的生态系统服务功能价值核算结果在本区域内有较高的可信度。

Arid areas in northwest China generally show ecological frangibility that has received widespread attentions.Land use/land cover changes and their ecological effects over arid areas thus draw much concern.The newly reclaimed area in the Yili valley is located at the northeast of Xinjiang Uygur Autonomous Region,China,bordering on Kazakhstan.This region is abundant in agricultural resources,and is therefore the primary production base of grain,oil,sugar and meat in Xinjiang.In order to reduce negative environmental influences resulting from exploitation of natural resources,in the present work,the authors examined the changes in ecosystem service value caused by land use changes,with providing some suggestions about sustainable development of agriculture in the newly reclaimed area.Remote sensing（RS）and Geographic Information System（GIS）techniques were utilized for data acquisition and processing.Two land use maps（1985 and 2000）of 1：100,000 provided by Data Center for Resources and Environmental Sciences,Chinese Academy of Sciences（RESDC）were utilized for this study.In addition,a land use map covering the study area in 2008 generated from the China-Brazil CCD satellite photo（resolution 19 m）and the high resolution HR satellite photo（resolution 2.36 m）was also used.The authors investigated in detail the land use changes over newly reclaimed areas in the Yili valley from 1985 to 2008 on the base of those data sources above.Moreover,the changes in ecosystem service value caused by land use changes were analyzed in three aspects：time,space and structure based on the framework of ecosystem service value evaluation proposed by Costanza,and the unit value-based method for ecosystem service assessment proposed by Xie.Results showed that：1）from 1985 to 2008,crop land greatly increased,and grassland showed a trend in degenerating into alkali or sandy lands;2）the ecosystem service value across the study area has been reduced by 6.19%at the same period.Concerning agriculture development over the newly reclaimed area in the future,it was suggested that protection of biodiversity and water conservation functions should be placed much more emphasis,preventing the area from a series of eco-environmental problems,like grassland deterioration and desertification,shrinking of lakes and wetlands,soil erosion and salinization caused by irrational development modes.On the other hand,much effort should be made in protecting biodiversity and natural conditions of the study area and the function of ecosystem service should be promoted through optimizing agricultural structures;3）the sensitivity analysis showed that the ecosystem service value（ESV）lacks of flexibility,indicating that the results of ecosystem service value evaluation are reliable.