【作者】 王耀宗；

【导师】 常庆瑞；

【作者基本信息】 西北农林科技大学 ， 地图学与地理信息系统， 2010， 硕士

【摘要】 退耕还林还草工程是我国为保护和改善中西部地区生态环境,实施的一项重要的生态恢复工程。因此,评价该工程建设成效,不仅对退耕还林还草工程的高效实施具有指导意义,而且对退耕区生态和社会经济发展具有深刻的理论价值和实践意义。本文选取我国水土流失严重,生态环境脆弱,退耕还林还草工程重点实施地区的陕北黄土高原退耕还林还草工程为研究对象。在遥感、GIS技术支持下,根据陕北黄土高原TM遥感影像,结合野外实地考察与采样,以及退耕还林的各种统计资料和数据,通过ERDAS和ARCGIS软件获取陕北黄土高原土地利用分类图,借助GIS空间分析方法和数理统计方法,引入景观格局空间分析和生态系统服务价值原理,选取一定的景观格局指数和生态环境评价指标,从生态结构合理性、生态环境质量等方面对退耕还林还草所取得的生态效应进行量化研究。本研究主要取得的主要结果如下:(1)基于监督分类和非监督分类相结合的方法获取的研究区不同时期土地利用分类图,从土地利用类型变化角度,引入景观格局分析方法和生态系统服务价值理论,进行了退耕还林生态效益定量研究,不仅考虑到退耕后林地带来的生态效益,还从区域整体生态环境质量变化尺度上,对退耕还林还草生态效益进行了定量评价。(2)陕北黄土高原生态系统组分合理化,景观结构区域多样化和复杂化。1997-2006年,陕北黄土高原利用类型发生了显著变化,50.37%耕地转换成林地和草地,整体景观多样性指数下降,景观破碎化程度下降。整个生态系统景观组分趋向合理化,景观类型多样化,这使得生态环境得到有效保护和恢复,促进了生态的协调发展。(3)陕北黄土高原生态环境指数提高,总体生态环境质量提高。研究区总生态环境指数从1997年的0.145上升到2006年0.157,生态环境指数明显增大,增幅为8.28%,说明陕北黄土高原退耕还林还草带来了较好的生态效益,林地、草地等相对生态价值高的植被类型显著增加,从而使整体生态环境指数提高,全区整体生态环境得到极大改善。(4)土地退化情况得到基本控制。从1997年到2006年,林地面积不断增长,草地质量提高,使得陕北黄土高原水土流失、土地沙化情况得到缓解,土壤形成与保护、气体调节、气候调节、水源涵养、生物多样性保护和娱乐文化生态服务价值均显著增加;总体生态服务价值量显著增加7.67×106元,年增长率为0.2%,土地利用/覆盖变化整体生态贡献指数变化明显,整体贡献指数为1.203,生态环境质量改善作用明显。退耕还林以来陕北黄土高原整体生态环境向着健康方向发展。更多还原

【Abstract】 To protect and improve the ecological environment in western and central regions of China, converting cultivated land to forest and grass project is an important and costly ecological restoration project implemented by Chinese government. Therefore, it has guiding significance for its effective implementation, practical meaningful and theoretical value to evaluate effect of this ecological construction.This paper took the typical regions-severe soil erosion and fragile ecological environment, the North Shaanxi Loess Platea as example, which was arable to forest project focused most on. With the RS and GIS technology, the classification data of land use was obtained. Then making classification map and analyze changes of the ecological environment through landscape pattern indices and ecological environment indices to evaluate effect after land use converting. The main results of this study were as follows:(1)Based on the classification map of land use in different years formed through the method of supervision and non-supervision, ecological effect could be quantitatively studied introducing the theory of landscape ecology and ecological service value. It was considered ecological benefits from changes of land use in the entire region caused by returning farmland to forest.(2)Ecosystem components in the North Shaanxi Loess Platea rationalized and diversified and the structure of landscape became complicated. From 1997 to 2006, area of grassland and woodland accounted for 50.37%. Compared with 1997,overall landscape diversity index decreased, the degree of landscape fragmentation decreased. The whole ecosystem of study area was effectively protected and restored so that it was good for keeping the balance of local ecosystem.(3)Ecological environment index rose up significantly from 0.145 of 1997 to 0.157 of 2006 with an increase of 8.28 percent, which indicated that this ecological restoration project had brought good ecological effect. High relative ecological value of forest and grassland with significant increase contributed to increase of ecological environment index. The local environmental quality greatly improved.(4)Land degradation had been under control. Area of woodland grew little by little, and large area of low coverage grassland turned into high coverage one. Soil erosion and land desertification were eased. Components of ecological service value all increased greatly. the total ecosystem service value increased 7.67×106 yuan and the annual increasing ratio is 0.2 percent, ecological environment has been a certain improved and overall environmental quality has been remarkably improved. The ecosystems in the county tended to develop healthily in North Shaanxi Loess Plateau with the development of the Conversion of Farmland to Forest Project.更多还原