【作者】 郭明；

【导师】 赵善伦； 肖笃宁；

【作者基本信息】 山东师范大学 ， 自然地理学， 2004， 硕士

【摘要】 西北内陆干旱地区，属于生态环境脆弱区，如何协调流域水—生态环境—经济发展之间的矛盾，使自然生态系统与人类生态系统实现生物共生与可持续协调，一直是亟待解决的重要科学问题，尤其是在西部大开发的背景下，西部地区的经济发展与其产生的生态环境问题就显得尤为突出。本论文从地区经济发展和生态环境建设应用实际出发，以景观生态学为理论指导，借助先进的遥感技术和地理信息系统技术，以位于甘肃省河西走廊中西部的酒泉市为例，进行该绿洲的景观制图，分析了酒泉绿洲的景观格局特征及其变化；并在此基础上，进行生态安全评价研究。最终为实现该区生态环境与社会经济的协调稳定发展，保护地区景观健康及维持区域生态安全提供科学依据。在本论文研究工作过程中，及时根据现场野外调查信息对研究内容进行了调整，力求与绿洲建设实际密切结合，为解决实际问题服务。通过研究得到如下主要结论。 1．酒泉绿洲景观生态类型图的生成 进行酒泉绿洲景观生态类型分类，建立遥感解译标志库。在此基础上，利用GIS软件(主要使用Arcview 3.2及NT版Arc／Info)，提取各景观要素并建立各景观类型的空间数据库，生成研究区两个时期的景观生态类型图并经野外验证。 2．酒泉绿洲景观结构及其变化分析 针对不同时期的景观图，利用Arcview 3.2、景观空间格局分析软件FRAGSTATS计算各景观指数，分析研究区景观的各种特征。得到如下结论： (1) 绿洲景观以戈壁荒漠类型为背景，呈异质性镶嵌分布，戈壁粒径粗大，类型间连通性强，聚集程度高；绿洲类型相对集中分布，与戈壁、盐碱基质类型相比，斑块密度较大，景观多样性丰富，各类型间相间分布明显，几乎完全受人类的调控中文摘要(2)(3)的斑块类型要比而受自然和人为双重影响的斑块类型的形状规则。绿洲“亲水性”特征体现在其景观格局的特征上。景观中各斑块的变化不一致，但总起来讲，整个景观(基于行政区尺度)的斑块密度增大，最大斑块指数减小，面积加权形状指数减小;斑块间的最邻近距离减小:景观中不同斑块类型的团聚、延伸程度减小，景观多样性及破碎化程度增加，表明86年时景观中的优势斑块类型的连接性较2000好，逐渐向具有多种要素的密集格局演变，景观更加破碎，土地利用越来越丰富。不同的研究尺度，得出的结论不一样，以行政区为研究尺度，其景观基质为戈壁荒漠类型;以绿洲为研究尺度，其景观基质为耕地。3.酒泉绿洲景观生态安全分析(1)沙漠化、盐碱化威胁分析。借助于GIS强大的空间分析功能，通过分析各绿洲景 观斑块类型与盐碱地、沙地斑块的空间邻接特征，得出，整个绿洲受沙漠化威胁 程度增大，受盐碱化威胁程度降低，沙漠化威胁加剧的程度大于盐碱化威胁减小 的程度。(2)绿洲的发育适度规模分析。本文利用基于现状的适宜绿洲面积的求算公式，计算 出1986年的绿洲面积还可增加，只是，绿洲内耕地面积过大，应退耕还林，还 草。2《X犯年绿洲及绿洲内的耕地面积比适宜绿洲及适宜耕地面积都要大，说明在 现状水资源水平下，酒泉绿洲的水量不能满足绿洲的生态需求，应适当退耕还林。(3)农业生态系统的功能效益分析。选取灌溉体系建设状况，水资源的利用水平，植 被与生态建设，农业发展程度，社会经济水平和绿洲景观结构等6个一级指标及 巧个二级指标，定量化分析酒泉绿洲的功能效益，从而在一定程度上反映了绿洲 的发育成熟度。总的变化情况表现出2000年比1986年绿洲发育程度明显提高。(4)绿洲稳定性分析。各斑块的净边缘效应之间的差异性缩小，说明景观斑块类型之 间的相互作用总体在下降，有利于保持斑块和景观的稳定性。绿洲稳定有序的结 构主要表现:点阵结构、斑块的规则图案和分布的规律性。更多还原

【Abstract】 Water resource is the main factor to influence the development of ecosystem in the inland river basins of the arid regions, northwest China. Especially ,with the exploitation in West China, the shortage of water resource and the contradiction of water resource allocation between economy and ecosystem have been severe constraints to the sustainable development of these regions, so it is essential to take these problems into account. In this paper, based on the principle of landscape ecology, using the Remoting Sense,GIS and a landscape structure analysis program, FRAGSTATS, taking Jiuquan oasis located in the middle reaches of Heihe River Basin as a example, the author studied the landscape pattern, change and ecological security. The conclusions are as follows:1. Make up the landscape type map of Jiuquan oasisFirstly ,we determined ecological classification of Jiuquan oasis landscape, then, build RS interpretation symbols of these types .On the basis of these data, using GIS (such as Arcview 3.2 and Arc/Info), we distinguished landscape elements and built spatial data base of these types. At last, the landscape type maps of Jiuquan oasis in 1986 and 2000 can be obtained.2. The analysis of landscape pattern and change of Jiuquan oasisAccording to the two landscape maps in 1986 and 2000, using Arcview 3.2 , its extended modules and FRAGSTSTS: spatial analysis program for quantifying landscape structure, we obtained the following results.(1) Oasis patches are heterogeneous mosaic of patches embedded in the matrix element Gobi-desert with absolute dominance.The characteristics of Gobi-desert are big patch size, high contagion. On the contrary, oasis types have relatively centralizedAbstractdistribution, big patch density and high diversity. These oasis types are largely distributed along rivers and channels, embodying the characteristic of hydrophilicity.(2) During the time from 1986 to 2000, the change varied with the patch type in Jiuquan oasis.But, as a whole, there is still a pattern of sharp contrast between oasis landscape and desert landscape . At administrative level, the denstity of landscape increased, the largest patch index decreased, the shape became more regularly, the diversity of landscape increased according to the SHDI and SHEI; at the same time, the landscape fragmentation degree ascended. As for the reason, the human activities have contributed to the landscape changes in Jiuquan oasis.(3) Study scale is very important in landscape ecology. We will draw different conclusions at different scales. At administrative level, the matrix is bare Gobi-desert, the landscape pattern embodied the characteristic of arid region, at oasis level, the Flat Glebe is the matrix.3. The analysis of ecological security of Jiuquan oasis(1) Threatened degree of desertification and salinization of jiuquan oasis. By using GIS, we studied the spatial neighboring characteristics between desert /salina and other oasis patch types in 1986 and 2000. Then, based on the foundation data, we calculated the threatened degree of desertification and salinization of jiuquan oasis. The results are as follows: the threatened degree of desertification increased, the threatened degree of salinization decreased , and the degree of desertification increase is stronger than the degree of salinization decrease.(2) The assessment of fitting oasis size and arable oasis size based on the actuality of water resource and the quantity of ecological water requirement. The result indicated that according to the present quantity of water resource in 1986, the area of oasis can increase 12608.07ha, but the area of flat glebe is bigger than arable oasis size; however, in 2000, the area of oasis is bigger than the fitting oasis size and the area of flat glebe is also bigger than arable oasis size. Ecological requirement can’t be satisfied, so the measure of moving back flat glebe to woodland should be taken.(3) We selected indices to quantify the function and benefit of the Jiuquan agriculture ecosystem更多还原