【作者】 徐斌；

【导师】 李德平；

【作者基本信息】 湖南师范大学 ， 自然地理学， 2011， 硕士

【摘要】 湖泊是人类赖以生存的重要湿地之一,现代湖泊的演化趋势问题已成为当前地学界高度关注的热点问题之一。而在湖泊的演化研究中,湖泊的差异沉降研究已成为目前国际地学前沿之一。洞庭湖盆地存在着不可忽视的地面沉降现象,并在一定程度上阻碍着该地区的快速发展。因此洞庭湖盆地非均匀沉降与抬升研究是“两型”社会建设的需要,也是堤垸加固与洪道清淤工程设计实施,防洪抗灾与湖区生态恢复研究的需要。前人研究的资料整理分析指出,构造运动、泥沙淤积和人为作用是洞庭湖盆地非均匀沉降的因素。尽管关于洞庭湖盆地非均匀沉降研究已经取得丰硕成果,但是得出的沉降值为平均值,且未有公开的研究区具体沉降示意图,所以本研究是具有一定学术价值和现实意义。本文基于DEM所作洞庭湖盆地非均匀沉降研究的主要工作如下：(1)下载了免费的SRTM 3与ASTER GDEM数据,经过投影转换以及数据重采样,应用地理信息系统(GIS)进行空间运算,得到整个洞庭湖研究区域的沉降分布示意图,并对该方法进行了初步分析。(2)收集了洞庭湖地区50年代和80年代两个时期的1：5万地形图,经过目视解译,确定沉降明显的四个代表性区域,提取高程信息,应用地理信息系统软件生成数字高程模型并展开了相应的空间分析,得到各个时问段内洞庭湖盆地的地面沉降分布示意图,通过对各沉降速率图的分析得出了四个代表性区域的沉降变化。(3)对比分析证实,构造运动、泥沙淤积和人类活动这三个主要诱导因子对洞庭湖盆地不同区域影响强度不同,从而造成各影响区域的不同沉降势态。(4)鉴于采用常规水准测量等其他方法进行地面沉降监测费时费力,提出利用合成孔径雷达差分干涉测量技术(D-inSAR)对洞庭湖盆地地面非均匀沉降进行监测的设想,并简要分析了其可行性。更多还原

【Abstract】 Lake is one of the most important wetlands in which we depend on to live. The evolution of modern lakes is one of the hotspot of the geography nowadays. Study on differential subsidence has become one of the frontline of evolution research of lakes. Significant land subsidence in Donting Lake basin impedes the fast development of this area in some degree. Study on differential subsidence and arise of Donting Lake basin is needed for construction of Two-oriented society, consolidation of embankment surrounded region, practice of desilting project, flood control, and restitution of the ecosystem.The former studies showed that tectogenesis, sediment deposition and human affect were influencing factors for differential subsidence. Although there were many achievements for differential subsidence of Donting Lake basin, the concrete value of subsidence is needed to replace the average value reported and specific and public schematic diagram for subsidence of the whole area of Dongting Lake is needed either. This study can redeem the deficiency and have a certain academic value and practical significance.This research about differential subsidence based on DEM is summarized as follows:(1) Schematic diagram for subsidence of the whole area of Dongting Lake is obtained by aerial image transformation of the free SRTM 3 and ASTER GDEM data combination with space operation by geographic information systems (GIS).The deficiency of this method is discussed either.(2) The topographical map of Dongting Lake area in 50th and 80th 20st respectively with a scale 1:50,000 were obtained. Schematic diagram for subsidence of the whole area of Dongting Lake in different time was showed finally after extracting the high-scale information by determination the four representative areas of obvious subsidence through visual interpretation combined with homologue space operation. The pattern of change for four representative areas of obvious subsidence were obtained by statistical analysis of each subsidence velocity diagram.(3) By comparative analysis,it is confirmed that the three main inducing factors of tectogenesis, sediment deposition and human activities affect different areas of the Dongting Lake basin with different intensity, and these factors also impact the region for differential subsidence.(4) An idea to monitor the differential subsidence of Dongting Lake basin by D-inSAR is raised as the common leveling surveying and other method is time-taking and exertion.更多还原