【作者】 叶红梅；

【导师】 王乘；

【作者基本信息】 华中科技大学 ， 空间信息科学与技术， 2009， 博士

【摘要】 生态安全是一个区域的可持续发展不致因生态环境遭受破坏而使受到威胁的状态。在影响流域生态安全的因素中，流域土地利用景观格局的变化是影响流域生态安全最重要的方面。疏勒河流域是我国河西走廊地区三大内陆河之一，是河西走廊重要的经济作物生产基地，具有极其重要的经济和战略地位。20世纪90年代后，随着农业开发工程的实施，疏勒河流域进行了大范围的水资源开发和土地资源开发(简称水土资源开发)，在很大程度上改变了流域的生态环境和景观结构。一些不合理的开发利用引发的一系列生态环境问题日益突出。尤其在移民开发项目实施后的十余年时间里，农业生产以及人口的增长都大大增加了对水资源的需求量；中游昌马灌区灌溉面积不断扩大，用于农业灌溉的水量不断增加，渠系利用率不断提高，对地下水补给量不断减少，流入下游安西—敦煌盆地地表水资源量持续减少；疏勒河流域下游地区地下水位出现下降的趋势，泉水资源量也不断衰减，安西县城附近泉水资源全部消失。与此同时，人工水利工程设施的建设改变了天然的流域水循环的时空分布，天然绿洲面积与水域面积急剧缩减，打破了原始的水循环平衡状态，干扰了原本平衡的绿洲水文生态系统，进而导致依赖于水循环的生态环境也发生了相应改变。流域的水土资源开发引起生态负效应问题引起了越来越多的专家学者的关注，由此面向生态安全的流域生态与水资源之间的可持续发展研究应运而生。然而，以往的研究大部分集中在水资源组成、演化和评价方面，而对面向生态安全的流域景观动态演变过程及其驱动机制研究甚少，目前大多数的研究都在观测点或观测断面上进行，从时间和空间相结合对流域尺度的流域生态演变规律和驱动机制的研究甚少。现代景观生态学是一门新兴的、正在迅速发展的学科，其产生和发展给传统的流域尺度的生态和地理研究带来了许多新鲜的思维。以遥感技术(RS)和地理信息系统(GIS)为代表的空间信息技术为分析流域尺度的涉及到时空的自然、地理和人文现象提供了有力的技术支撑。随着景观生态学和空间信息技术的的不断发展，运用景观生态学的理论与方法，在空间信息技术的支持下，分析流域景观格局，探讨景观变化过程、演变机制及其调控机理，已经成为流域研究的热点。景观生态学可以为流域的景观格局，景观演变过程，景观动态模拟等研究提供理论支持和有效的研究路径。空间信息技术可以为流域生态水文研究提供数据支持、分析平台和模拟途径。本论文在掌握基础地理资料、水文地质资料、植被遥感影像资料、地下水埋深历史监测资料和前人的研究成果基础上，运用景观生态学、水文地质学和空间统计学原理，应用遥感技术、地理信息系统技术对干旱内陆河流域的典型流域——疏勒河流域展开研究。论文在景观生态学、水文地质学和空间统计学基础上，分析了疏勒河流域景观格局特征，建立了面向生态安全的流域景观演变及其驱动机制研究框架，主要包括内陆河流域绿洲景观格局分析、内陆河流域绿洲景观演变时空动态变化分析、流域景观演变的驱动机制、流域植被生态需水量模型与应用等。在对内陆河流域景观格局及变化分析的基础上，提出了利用2000～2008年间MODIS植被指数数据研究流域尺度景观动态的新方法，剖析了疏勒河流域生态系统的演变过程和规律。从地下水埋深、天然水系分布、地形等方面分析了流域景观格局演变的自然驱动机制，从人工渠系分布、灌溉机井分布、道路交通分布、居民地分布等方面分析了流域景观格局演变的人为驱动因素。在建立驱动因子的空间分布数字模型的上，通过对驱动因子与反映流域生态的植被指数之间的耦合关联分析，得出各个驱动因子与植被指数之间的相关系数，定量分析了疏勒河流域景观演变的驱动机制。在景观时空动态模拟上，比较分析了目前流行的几种景观格局变化模拟模型，采用了CLUE-S模型模拟流域典型区域的未来景观演变。在该模型中，综合考虑了地下水埋深、天然水系分布、地形、人工渠系分布、灌溉机井分布、道路交通分布、居民地分布等环境驱动因子，利用二元Logistic回归分析得出各驱动因子与景观类型的二元回归模型，确定景观单元之间转化的概率。在以往生态需水计算模型的基础上，提出了利用空间关联分析方法计算生态地下水位埋深值的新方法。建立了适宜于疏勒河流域的生态需水模型，结合生态地下水位埋深值的分析结果和基于“3S”技术的潜水蒸发法和给水度法分别计算了流域内不同植被景观内的植被生态需水量，为流域尺度的面向生态的水资源配置提供了有益的参考。最后，总结了论文中存在的不足，并针对不足之处对未来的研究进行了展望。更多还原

【Abstract】 Ecological security is defined as the undamaged or unthreatened conditions of eco-environment for regional sustainable development. The dynamic landscape pattern of land use is the most important driving factor that influences the watershed’s ecological security. The Shule River is one of the three most important rivers in Hexi Corridor region of China. It plays an important role in the production of economic crop, and occupies an extremely important position of economic and strategic in China. After the 90’s, with the implementation of agricultural development projects, the developments and utilizations of water resources and soil resources (referred to as water-soil resources) has been going in the Shule River Basin, which has changed the ecological environment and landscape pattern of the Basin. The unreasonable and transitive utilization of the resources have caused a series of eco-environmental problems. Particularly in the past ten years after the implementation of the migration and development project which began in 1996. The development of agriculture and the growth of population have greatly increased the demand on water resources. The irrigated areas in Shuangta, Changma and Huahai irrigated districts have been expanded, which requiring the increasing amount of required water used for agricultural irrigation. To meet the requirements of the irrigated water, most of the water flowed into channels for increasing the utilization rate of water. As the result, the amount of groundwater recharge has been declined, and the total volume of flows falling into the lower reaches of Anxi-Dunhuang Basin has been decreasing continuously. On the one hand, the groundwater level has been declining in the basin, while the spring water has disappeared. On the other hand, the construction of artificial facilities in the basin has changed the natural water cycle of the temporal and spatial distribution of water, which resulted in the distribution of original ecosystems’ balance, and the negative effects caused by the soil and water resources development rose such as the sharply decline of natural oasis, salinization of soil, desertification of soil, and so on.These negative effects have caused more and more attentions from the entire world. However, most previous studies focused on the composition, evolution and evaluation of water resources, most of the previous researches were carried out by analyzing into point data statistically. The researches on the evolution of landscape pattern and its driving force are few, the researches on the perspective of two-dimensional combination of temporal and spatial are even fewer.Landscape ecology is a new rapidly developing discipline; it has brought a lot of fresh perspectives for traditional ecology and geography. The spatial information technologies including remote sensing technology (RS) and geographic information systems (GIS) provide strong technical support to the analysis of natural, geographic and cultural phenomena with different spatial and temporal scales. With the development of landscape ecology and spatial information technology, the researches focus on landscape pattern and its dynamic evolutions, driving force and its simulation of the future evolution have become more and more popular in the arid and semi-arid districts all over the world. The theories of Landscape ecology and spatial information science have provided strong theoretical support. Especially, the spatial technologies have provided the integrated platform for spatial analysis and spatio-temporal simulation.In order to explore the dynamics of Shule River basin’s landscape pattern and the driving mechanism, this thesis focused on the research of the evolution of watershed landscape pattern between 2000～2008 based on the availability of topographic maps, hydro-geological data, remote sensing vegetation indices’ images, monitored historical groundwater level’s data and the previous researches’ results. This thesis focused on the following researches according to the theories of landscape ecology, hydrogeology and spatial statistical principle.(1) This thesis analyzed the landscape pattern and its dynamic evolution using time series MODIS vegetation indices data in Shule River basin.(2) This thesis proposed a new approach for exploring the driving mechanisms by spatial correlated analysis. Firstly, the driving factors were classified into the natural driving factors and man-made driving factors. The natural driving factors include natural river network and terrain; the man-made driving factors include the distribution of artificial canal network, the distribution of irrigated well, the distribution of road traffic conditions, the conditions of the residents and so on. Secondly, we established the coupling models between vegetation indices and driving factors based on spatial distribution models, which were established by spatial interpolation models. Thirdly, the correlation coefficients between various driving factors and vegetation indices were obtained by statistic analysis.(3) The thesis proposed a new approach on calculation ecological groundwater level using spatial correlated analysis into groundwater and vegetation indices. Based on the analysis to the formal model of ecological water, new ecological water calculation model was established. Finally, the ecological water requirement within different three vegetation landscape was calculated based on evaporation models and "3S" technologies, which provides a new way for calculation of watershed scale ecological water requirement.In the end of the thesis, some suggestion was proposed for the further research basedon the analysis into the deficiencies of the thesis.更多还原