典型区域退耕还林工程生态区划

Ecoregion division of Grain for Green Project in the typical region

【目的】退耕还林工程作为我国乃至全世界最大的生态建设工程,发挥着重要的社会、经济和生态效益。长江流域中上游地区是我国重要的生态区,也是退耕还林工程实施和生态效益监测的重点地区,工程实施面积占到全国退耕面积的33.60%。为了对该区域退耕还林工程的生态效益进行全面、系统、科学地定量化监测和评估,对长江中上游地区退耕还林工程进行生态区划十分必要。【方法】结合退耕还林工程实施范围、年平均降水量、≥10℃积温、地貌数据以及中国行政区划,应用地理信息系统空间分析中叠加分析法,区划得出长江流域中上游地区退耕还林工程生态区。【结果】分别选取地貌、水热条件和退耕还林工程水土保持功能强度作为3个级别的区划指标,得到1级区域4个,2级区域19个,3级区域31个。【结论】基于能够表征其特性的多重指标对长江流域中上游地区退耕还林工程范围进行区划,直观地反映了该区域的实际地理分域规律,为其生态效益监测与评估奠定基础,便于对相应生态区的生态效益结合其所属的区划指标进行合理的分析,用分区特征来印证生态效益的评估结果。

[Objective]As the largest ecological construction project in China even in the world,Grain for Green Project exerts a series of important social,economic and ecological benefits. The region containing the upper and middle reaches of Yangtze River is the significant ecoregion of China,and key areas of Grain for Green Project implementation and monitoring ecological benefits,of which project area accounts for 33. 60% of the national farmland area. To quantitative evaluate the ecological benefits of the region＇s Grain for Green Project comprehensively, systematically and scientifically, dividing theecoregions was indispensable. [Method] First, we chose the map of Grain for Green Project implementation,mean annual precipitation,annual accumulated temperature above 10 ℃,important ecological functions of Grain for Green Project and geomorphic types as the data sources. Then,we selected geomorphic types,hydrothermal conditions and strength of soil and water conservation function of Grain for Green Project as three levels of regionalization indicators. [Result] Finally,we applied the geographic information system（ GIS） space analysis to get the ecoregions. We got 4 class Ⅰ areas,19 class Ⅱ areas and 31 class Ⅲ areas. [Conclusion] Based on multiple indicators, which could characterize the features of Grain for Green Project in the region containing the upper and middle reaches of Yangtze River,ecoregions intuitively reflected the actual geographical regional rules. Meanwhile,it lays the foundation for ecological benefit monitoring and evaluation of the region＇s Grain for Green Project. This contributes to combine with its regionalization indicators when analyzed the ecological benefits of corresponding zones,using regionalization characteristics to verify the results of ecological benefit assessment.