Knowledge Resource Center for Ecological Environment in Arid Area
| 蒙古高原土地荒漠化特征与变化分析 | |
| 其他题名 | Research on the Land Desertification of the Mongolian Plateau and Analysis on the Dynamic Change |
| 张韵婕 | |
| 出版年 | 2016 |
| 学位类型 | 硕士 |
| 导师 | 刘庆生 |
| 学位授予单位 | 中国科学院大学 |
| 中文摘要 | 蒙古高原位于我国北部和蒙古干旱半干旱地区，具有重要的政治、经济及地理区位特征，且其作为相对独立的一级地理和生态单元，其生态系统状态及其变化对于中国北方乃至整个东北亚地区的生态安全有着重要作用。近几十年来，由于受全球变化的影响，我国干旱半干旱区的气候有增温趋势，异常和极端气候过程（如干旱、暴雨、强风、严寒）发生频率上升，加之当地盲目开垦、过度放牧、保护不力等人为因素的影响，土地荒漠化严重，区域生态环境面临严峻压力。干旱半干旱区气候变化与包括水文、生态在内的各种物理、化学和生物过程密切相关，其变化规律和动力机制非常复杂，是一个多学科交叉的科学难题。基于时序遥感数据对蒙古高原干旱区半干旱区地表信息进行监测，建立荒漠化评价体系，对于探究该区土地荒漠化造成的生态环境变化具有重大意义。鉴于此，本文对蒙古高原的植被、土壤进行了一系列相关研究，结合野外实测数据建立适用于研究区的评价标准，分析研究区荒漠化现状及1982-2013多年来的荒漠化动态变化，研究成果有：通过对蒙古高原的植被—土壤因子关系的定量探究，发现蒙古高原的植被生物量主要受土壤有机质、全氮含量的影响，与这两个因子均为正相关关系。这表明，蒙古高原的植被状况可以反映土地质量，进一步体现土地退化状况。因此，可以将植被作为区域尺度荒漠化评价的主体；蒙高原植被的生长状况与降水量有极显著的正相关关系。因此，在荒漠化监测研究中，有必要消除降水的影响；选用植被降水使用效率（RUE）作为评价蒙古高原荒漠化程度的指标，经野外采样数据验证，使用RUE作为指标建立的荒漠化分级标准适用于蒙古高原地区；从时空两个角度分析1982-2013年荒漠化动态变化，发现逆转面积远小于恶化面积。因此，研究区的荒漠化程度加剧，土地荒漠化在进一步发展，有待治理；从自然和人文两个角度分析荒漠化动态变化的驱动因子，发现降水和气温均是影响蒙古高原土地荒漠化的自然驱动因子，且荒漠化程度与降水量呈负相关关系，与气温呈正相关关系，同时土地利用结构的变化影响荒漠化的发展，草地退化、裸地增加的趋势与荒漠化的恶化趋势基本一致。此外，人口增加加剧了草地的退化及裸地的增加，使得研究区土地荒漠化程度加强。 |
| 英文摘要 | The Mongolian Plateau, of which location counts a lot in the political, economic and geographic areas, consists of the northern part of China and the entire region of Mongolia. As an independent geographical and ecological unit, the plateau’s ecosystem and its dynamic change have significant impact on the Northern China and even Northeast Asia. In the arid and semi-arid regions of China, In recent decades, climate warming has occurred and extreme weather such as drought, storm, strong breeze and severe cold has appeared more frequently than before. Besides, there exists serious desertification in the Mongolian Plateau as a result of over grazing , ineffective protection and so on. We have encountered sever environmental pressures in the Mongolian Plateau.Closely related to hydrology and ecology which include many physical, chemical and biological processes, the climate change of the arid and semi-arid regions is a multidisciplinary problem and it’s difficult to figure out its law and mechanism. Establishing a desertification evaluation system for the Mongolian Plateau and then monitoring its ground surface information has a great significance for the scientific research on the desertification ecosystem.Based on the remote sensing data and field survey data, this paper has done a series of experiments on the vegetation and soil in the Mongolian Plateau and made an analysis into its desertification status and the dynamic change throughout 32 years from 1982 to 2013. We’ve made quantitative analysis of the vegetation and soil based on the field survey which produced large amounts of data about vegetation biomass and edaphic factors in the arid and semi-arid region of the Mongolian Plateau. The result shows that in the study area, the organic matter of the soil is rich as a whole with a polarized distribution. The soil in the study area is high in the content of rapidly-available phosphorus and potassium in the soil but low in the content of soil total nitrogen. The vegetation biomass is uniformly distributed around the study area and the grassland produces more biomass than the bare land. Besides, the biomass is mainly affected by the content of the organic matter and total nitrogen in the soil and positively correlated with the two factors. We conclude that the vegetation status could reflect the land quality, so we could take vegetation as the main body of the desertification evaluation. Based on time series analysis methods, we calculate the slope of the fitted line of NDVI for each single grid cell, which is set as the indicator of the intensity of dynamic changes; combined with meteorological data, we use the correlation analysis to explore how the natural factors affect the ecosystem. The results show that the area with significant positive correlation of NDVI and precipitation in the area has a significant positive correlation with precipitation. Overall, we select Rain Use Efficiency (RUE), which is calculated by the division of Net Primary Production (NPP) and precipitation, as the evaluation indicator to classify the Mongolian Plateau.By comparing the desertification status of the Mongolian Plateau in 1982, 2000 and 2013, we find out that there are more desertification areas in 2013 than that in 1982. However, the status has become better since 2000 as there is less desertification area in 2013 than that in 2000. Besides, by making an analysis into the driving forces of desertification, we find that precipitation and temperature has great effect on desertification, and higher temperature and less precipitation could lead to severe desertification status. Apart from natural factors, human factors like land use structure and population also affect desertification. |
| 中文关键词 | 蒙古高原 ; 荒漠化评价 ; 植被降水使用效率 ; 变化分析 ; 驱动因子 |
| 英文关键词 | the Mongolian Plateau， desertification evaluation， Rain Use Efficiency，analysis on the dynamic change，driving factors |
| 语种 | 中文 |
| 国家 | 中国 |
| 来源学科分类 | 地图学与地理信息系统 |
| 来源机构 | 中国科学院地理科学与资源研究所 |
| 资源类型 | 学位论文 |
| 条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/287643 |
| 推荐引用方式 GB/T 7714 | 张韵婕. 蒙古高原土地荒漠化特征与变化分析[D]. 中国科学院大学,2016. |
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