中国科学院机构知识库网格系统: 西藏冻融侵蚀研究

中国科学院机构知识库网格

Chinese Academy of Sciences Institutional Repositories Grid

西藏冻融侵蚀研究

文献类型：学位论文


作者	张建国
学位类别	博士
答辩日期	2005
授予单位	中国科学院研究生院
授予地点	北京
导师	刘淑珍
关键词	冻融侵蚀西藏 GIS技术分级评价
学位专业	自然地理学
中文摘要	《西藏冻融侵蚀研究》是立足于西部生态环境建设与可持续发展而开展的基础性、探讨性的研究。以西藏自治区为研究区域，主要探讨冻融侵蚀区的界定、冻融侵蚀的分类、冻融侵蚀分级评价、冻融侵蚀空间分布规律、冻融侵蚀的危害及防治策略等方面的问题。论文首先通过大量野外调查结果对冻融侵蚀的定义进行了明确，根据野外调查和前人工作分析研究，提出了青藏高原冻融侵蚀区界定的理论依据，并在GIS平台支持下对西藏冻融侵蚀区进行了界定。然后对西藏冻融侵蚀进行了初步分类和分区。之后从影响冻融侵蚀发生发展的因子出发，建立了冻融侵蚀加权加和综合评价方法，并利用该方法，在GIS平台支持下对西藏冻融侵蚀进行了综合评价。最后通过野外调查和已有结果分析总结，详细阐述了冻融侵蚀的主要危害，并提出了防治策略。本研究得出的主要结论如下：（1）青藏高原冻融侵蚀区的下界与冻土学当中的冰缘区的下界更为接近，取冰缘区的下界作为冻融侵蚀区的下界更为合理；雪线以上仍发生冻融作用，只是其强度相对较弱，因此雪线不是冻融作用的上限；西藏冻融侵蚀区是从以公式5-2计算的海拔以上的区域中剔除以冰川侵蚀和风蚀为主的区域后的区域。（2）西藏冻融侵蚀按冻融的作用和过程及所形成的地貌形态可分为冻融风化侵蚀、冻融泥流侵蚀、冻融分选侵蚀、冻融滑塌侵蚀等类型。根据不同区域冻融侵蚀主要分布类型的差异可将西藏冻融侵蚀区划分为以下几个区：I．喜马拉雅山南坡峡谷和藏东南高山深谷冻融侵蚀区；II．三江上游冻融侵蚀区；III．藏北高原冻融侵蚀区；IV．藏南山原湖盆宽谷冻融侵蚀区。（3）西藏冻融侵蚀分布面积广大，总面积达664317.4km2，占该区国土面积的55.3％，是我国冻融侵蚀分布面积最广的一个地区，也是我国冻融侵蚀面积占国土面积最大一个地区。（4）西藏冻融侵蚀区域分异明显，不仅不同强度的冻融侵蚀空间分异明显，而且在不同地区具有不同的冻融侵蚀空间分布特点。（5）西藏冻融侵蚀的危害主要表现在破坏草地资源、加速土地荒漠化进程、破坏水利、交通等工程设施、加强水蚀和风蚀的危害性等方面。（6）目前防治冻融侵蚀的主要策略是：1．提高认识，加快对冻融侵蚀的研究，为防治冻融侵蚀提供技术支撑；2．建立和完善科学合理的地方性水土保持法规体系和一支高素质的执法队伍，提高冻融侵蚀区水土保持监督管理执法水平；3．控制人口增长，减轻对草地资源的压力。
英文摘要	The study of the freeze-thaw erosion in Tibet is a fundamental and discussible research for construction eco-environment and sustainable development in west China. Taken Tibet Autonomous Region as study area, the content of this research include: (1) the defining of the freeze-thaw erosion area; (2) the types sorting of freeze-thaw erosion; (3) the classification and assessment of freeze-thaw erosion; (4) the distribution of freeze-thaw erosion; (5) the hazards of the freeze-thaw erosion and the strategy for controlling the freeze-thaw erosion. First, according to the results of the field works, the definition of freeze-thaw erosion was revised, and the freeze-thaw erosion in Tibet was sorted into four types. Moreover the freeze-thaw erosion area in Tibet was divided into four subarea. Secondly, based on the analysis of existing relevant research result, a theoretical basis for the defining freeze-thaw erosion zone in Qinghai-Tibet plateau has been established, and the free-thaw erosion zones in Tibet has been identified by using GIS software. Then, a weight sum method for classification and assessment of freeze-thaw erosion in Tibet was established based on the comprehensive analysis of impact factors of freeze-thaw erosion, and realizes the relative classification and assessment of the freeze-thaw erosion in Tibet under the support of GIS software. Finally the main hazards of the freeze-thaw erosion were expounded and the strategy for controlling freeze-thaw erosion was put forward according to the results of the fieldworks and the other research. There are many conclusions as follows: (1) The lower bound of the freeze-thaw erosion zone in Tibet is much closer to the lower bound of the periglacial zone defined in the cryopedology. So, it is more reasonable to regard the lower bound of the periglacial zone as the lower bound of the freeze-thaw erosion zone. The snowline is not the "freeze-thaw upper bound" because freeze-erosion still occurred in area higher than snowline, only the intensity of freeze-thaw processes above the snowline is slight. The freeze-thaw erosion area in Tibet is the areas above the altitude calculated according to Formula (5-2) deducting the areas, which mainly suffer glacier erosion and wind erosion. (2) According to the freeze-thaw process and the landforms caused by freeze-thaw erosion, the freeze-thaw erosion in Tibet can be sorted into four types: weathering erosion, solifluction erosion, filtration erosion, and slide and collapse erosion. According to the diversity of main types in different regions, the freeze-thaw erosion area in Tibet can be divided into four subsections as followed: I. The area in south slope of Himalayan Mountain and the area in south-eastern Tibet; II. The area in upper reaches of Jingsajing River, Lantsang River and Nujiang River; III. The area in northern Tibet Plateau; IV. The area in dales around lake basins in southern Tibet plateau. (3) The freeze-thaw erosion is widely distributed in Tibet. The freeze-thaw erosion area reaches 664317. 4 km2, accounting for 55.3% of the land area of the Tibetan Autonomous Region. Tibet is the greatest distribution area of freeze-thaw erosion in China, and the proportion of freeze-thaw erosion to overall areas is greatest in China. (4) The differentia of freeze-thaw erosion is evidently, not only of the spatial distribution of different intension, but also of the spatial distribution in different regions. (5)The hazards of freeze-thaw erosion in Tibet include destroying the grassland resources, accelerating the process of land desertification, destroying irrigation works and traffic infrastructure, strengthening endanger of water erosion and wind erosion. (6)At present, the main strategies of preventing the freeze-thaw erosion include: 1. pay more attention to freeze-thaw erosion, advancing its study in order to provide the technological support for preventing and curing the freeze-thaw erosion; 2.building and perfecting scientific and reasonable water and soil conservation law system and competent tipstaff, improving the level of executing the supervision of water and soil conservation in freeze-thaw erosion areas; 3. controlling the population growth to alleviate pressure on grassland resources.
公开日期	2013-08-16
源URL	[http://ir.imde.ac.cn/handle/131551/6192]
专题	成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前）
推荐引用方式 GB/T 7714	张建国. 西藏冻融侵蚀研究[D]. 北京. 中国科学院研究生院. 2005.

入库方式： OAI收割

来源：成都山地灾害与环境研究所

浏览0

下载0

收藏0

其他版本

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。