IMHE OpenIR  > 山地表生过程与生态调控重点实验室
Alternative TitleThe study of the land cover changes and the simulation of soil water-thermal regime of the source of Yangtze and Yellow River
Thesis Advisor王根绪
Degree Grantor中国科学院大学
Place of Conferral北京
Degree Name硕士
Degree Discipline自然地理学
Abstract利用1969年航片数据、1986年、2000年、2007年以及2013年的TM影像数据对比分析出长江黄河源区的高寒草地和高寒湿地两大生态系统的时空变化特征,结合该地区的气候资料和人类活动状况,分析长江黄河源区土地覆被格局在全球变化背景下的变化趋势,并利用统计和模型模拟分析该变化与各气候因素和环境因子的关系。成果如下: 1、近45年长江黄河源区高寒草地呈现以覆盖度降低、破碎化与干旱化加剧为主的退化趋势。气温升高引起的区域的暖干化是导致长江黄河源区高寒草地生态系统退化格局的形成主要原因。过度放牧和人类不合理的开发是导致长江黄河源区高寒草地退化加剧的重要因素。 2、1969-2013年间,江河源区的高寒湿地面积减少了19.16 %,各湿地类型的斑块分离度不断增大;空间上,高寒湿地的退化区主要分布在长江源区的东北部以及黄河源区的北部地区;气温升高是形成湿地退化格局的主要原因,降水量和相对湿度的变化会对湿地的变化产生重要影响;载畜量的变化是影响湿地变化最重要的人为因素。 3、经过参数校正后的Noah LSM模型能够有效的模拟出该地区的土壤温度和土壤水分动态过程,土壤的温度的模拟精度在85%以上,土壤水分的模拟精度在89%以上,因此将Noah LSM用于多年冻土区水热通量过程的模拟是可行的。
Other AbstractThe Source Region of Yangtze and Yellow River is located in the central area of Tibetan Plateau and is the glacial source of Yangtze River and Yellow River, which plays a quite important role in the regional climate and water cycle.The Source Region of Yangtze and Yellow River is more sensitive to climatic warming than others under the global climate change due to the special alpine ecosystem and widespread permafrost.With the marked change of air temperature and precipitation, the land cover pattern and permafrost distribution over this region have been shown some detectable changes, which will have a great effect on the regional climate change, water cycle progress, ecological protection, and carbon storage.So the temporal trend and spatial variability of land cover pattern and the mechanism of land surface process in the central region of the Tibetan Plateau under climate change become a main focus of attention. The objectives of this study were to determine the spatial and temporal patterns of vegetation dynamics and the relationship between different environmental factors in the Source Regions of Yangtze and Yellow Rivers , and that was studied from macro and microcosmic angles. On one hand, the spatial and temporal characteristics of the alpine grassland and alpine wetland changes over the source regions of Yangtze and Yellow Rivers were analyzed by using the spatial dataset obtained from the aerial photo in 1969 and the TM remote sensing data in 1989, 2000, 2007 and 2013. In addition, with the climatic observation data and human activities, the trend of land cover pattern dynamics and the driving factor were analyzed by a principal component analysis model and the gray correlation method. In the other hand, using the meteorological data and soil temperature and humidity data with a high time resolution from Fenghuo Mountain test station, we tested the applicability of Noah LSM on the single point of permafrost region and improve the parameterization scheme of it. So, we can try to simulate the water-thermal regime of the permafrost regions. The results indicated: 1. The alpine grassland degradation characterized as reducing in coverage, increasing in fragmentation and desertification. The total area of Mid-cover Alpine Grassland and High-cover Alpine Grassland was decreased by 16.33% from 1969 to 2013. With the aggravation of drought, the total area of Alpine Meadow was decreased by 3.75% during the same time. The fragmentation and separation of landscape pattern of Alpine Grassland is increasing for disappearing and shrinking of patches. The rate of the degradation was increasing very fast after 1980s, and reached its maximum in 2000. Then, the degradation ratio was consistently deceasing after 2000. The climate drought caused by warming was the main reason for the alpine grassland degradation in the source regions of Yangtze and Yellow Rivers, and overstocking and unreasonable human activity were the important factor for the intensifying degradation. 2. Areas of alpine wetland in the Yangtze River and Yellow River source regions were decreased by 19.16% from 1969 to 2013. The spatial separation patch between each kind of alpine wetland increased. The degradation of alpine wetland were mainly occurred in the northeastern Yangtze River source regions and the northern Yellow River source region, which was consistent with the permafrost degradation in this region. The trend of climate change in this region has been warming and drying with significantly increasing in the air temperature, decreasing in the relative humidity and slightly increasing in the precipitation since 1969. There was obvious time synchronization between alpine wetland degradation and climate change. Thus, the great increase in air temperature was considered as the main reason caused alpine wetland degradation, and the rainfall and relative humidity change had a great effect on the wetland variation, especially more significant effect on the rivers an
Document Type学位论文
Recommended Citation
GB/T 7714
杜际增. 长江黄河源区土地覆被变化与土壤水热状况模拟研究[D]. 北京. 中国科学院大学,2015.
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