【作者】 许倍慎；

【导师】 周勇；

【作者基本信息】 华中师范大学 ， 人文地理学， 2012， 博士

【摘要】 土地是人类赖以生存的和繁衍的第一资源,土地资源具有生产和养育功能、承载功能和生态功能。土地覆被是指自然营造物和人工建筑物所覆盖的地表诸要素的综合体,偏重于土地的自然属性；土地利用是人类根据土地的特点,按一定的经济和社会目的,采取一系列生物和技术手段,对土地进行的长期性或周期性的经营活动。由于人类不断加大对土地资源索取和改造的力度,水土流失、森林消失、土地退化、沙漠化、盐渍化和各种环境污染现象愈发突出,人类越来越意识到土地利用及由此带来的土地变化不仅仅是简单的资源问题,更是全球变化的重要组成部分和造成全球环境变化的重要原因。因此将土地利用／覆被变化和区域生态安全、社会保障等区域发展问题紧密结合,研究土地利用／覆被变化对人类社会生存和可持续发展带来的反馈作用和以及人类的响应机制是地理学研究的重要课题。江汉平原位于湖北省中南部,是我国湖泊密集度最大的淡水湖群区。从区域发展战略上来看,江汉平原位于东部属于武汉城市圈的范围,西部属于“宜—荆—荆”城市群,是湖北省东西两大城市集群相接和交汇的重要区域,本身也是沿长江经济带的重要组成部分,区位优势十分明显,发展潜力巨大；江汉平原由于优越的自然地理条件和悠久的农业开发历史,自古以来物产丰富,是湖北省主要的农业生产区域和粮食主产区、我国重要的商品棉生产基地；同时,江汉平原以其独特的湖群、湿地分布特点,是湖北省重要的湖泊湿地生态区和武汉城市圈的生态屏障,对维持区域生态环境质量和生态安全具有重要作用。由于江汉平原自然、区位条件优越,经济基础较好,是我省承接东部发达地区产业转移的重要区域,又承担着粮、棉生产和区域生态维护等多种社会、生态功能,其土地生态系统经受着高强度的开发与利用以及各种外界压力的干扰。多种角色的叠加使江汉平原成为我国较为特殊的地理区域,因此针对江汉平原区域开展土地利用／覆被变化研究,了解区域土地利用类型变化的趋势和特点,分析区域土地覆被景观格局演变的影响因素,并对区域生态环境质量状况进行评价,不仅是当前地理学研究的重要领域,也对促进区域人口、资源、环境与经济协调发展有着重要的实践指导意义。本文的主要内容共分为8章：第一章为绪论。阐明了本研究的意义；通过对国内外大量研究资料的收集和整理,从土地利用／覆被时空演变规律、土地利用／覆被变化驱动力、土地利用／覆被变化环境效应研究和景观格局演变与生态评价等方面梳理了土地利用／覆被变化及生态效应的研究进展；同时通过江汉平原区域相关研究实践进行总结,发现现有的研究多从某一侧面对江汉平原区域的土地利用／覆被变化进行分析,21世纪以来江汉平原土地利用／覆被变化和景观格局时空演变的总体分析较少,也很少出现对江汉平原整体范围生态安全状况的定量分析。第二章为本文的研究方案。在第一章研究的基础上,针对现有研究中暴露出来的问题,确定了本文的研究目标：完善国内对江汉平原20多年来土地资源和生态状况演变过程的了解,增强对江汉平原景观格局形成的影响因素和驱动机制的研究深度,为我国平原湖区土地资源合理利用、生态环境问题的治理和改善、生态系统的规划与管理以及社会经济和生态环境的协调、可持续发展提供支持。同时介绍了本文的基本研究内容,包括江汉平原土地利用/覆被信息综合数据库的建立、1987年至2010年江汉平原土地利用/覆被时空变化分析；1987年至2010年江汉平原多尺度景观格局演变分析；江汉平原景观格局梯度与影响因子响应分析和江汉平原土地生态安全格局评价。并对研究中所使用的方法、技术路线和研究区范围、整体情况进行了介绍。第三章为江汉平原土地利用/覆被信息综合数据库的建立。运用数据库和地理信息系统技术整合了江汉平原范围内15个县市共2823406公顷范围内1987年、1995年、2000年、2005年、2010年5个时期各地类土地利用/覆被数量变化、空间变化情况；对应时空范围的景观格局变化情况；研究区范围遥感影像数据、研究区的数字高程模型、坡度数据、坡向数据、土地质量数据；研究区历年来的气象统计数据和人口、经济、社会发展数据等,并以该数据库为后期各项研究的基础平台。第四章为1987年至2010年江汉平原土地利用/覆被时空变化分析。通过1987年、1995年、2000年、2005年和2010年5个时相的土地利用情况为基础,运用动态度模型、土地利用综合程度模型、重心模型和土地利用转移矩阵等方法对江汉平原土地利用时间变化与空间分异进行了分析。研究发现江汉平原的土地利用特点以耕地为主导利用类型,耕地质量普遍较好,水域面积丰富,土地开发利用程度高。研究期间,各土地利用类型变化幅度差异大,区域分异明显,1987年至2010年耕地是变化数量最大的地类,共减少74589.51 hm2；水域是面积增长最大的用地类型,但湖泊水域面积呈下降趋势；从土地利用变化的区域分异来看,东部地区土地类型变化的幅度高于西部地区。研究期内江汉平原土地利用类型之间的相互转化模式以耕地和水域之间的相互转化为主体,耕地转换为水域的面积最大,但主要是转换为坑塘水面；耕地、水域和自然保留地之间的相互转化密切；建设用地主要为单向转入趋势,研究期间增加12995.62hm2,大部分来自于耕地。江汉平原土地利用变化过程中带来的主要问题有耕地数量减少幅度大,人均耕地面积减小,建设用地增长快,人地矛盾日渐突出；土地利用程度逐年提高,土地压力增大；生态用地面积减小,特别是林地、湖泊、自然保留地面积持续缩减,区域环境压力增大。第五章为江汉平原多尺度景观格局演变分析。通过从江汉平原总体尺度和10×10km网格尺度两个水平上对江汉平原范围内各种景观类型的斑块个数、斑块密度、平均斑块面积、面积加权形状指数和面积加权分维度指数进行了计算和分析,研究发现耕地景观斑块个数增加,斑块面积减小,带来斑块密度的上升,斑块形状日趋复杂,平原东部和东南部各指数的变化幅度大于平原西部地区；林地、草地、自然保留地景观各指数在江汉平原整体尺度上表现为覆被面积减少,在平原上分布更不均匀,逐步向西部、西南部退缩,同时斑块个数减小、斑块平均面积增大,形状变复杂；水域景观斑块个数增加、平均斑块面积减小,破碎度上升,同时斑块的形状变得简单,水域景观的空间分布也变得更不均匀；建设用地景观斑块增多、平均斑块面积增大、斑块密度增大,斑块的复杂程度加大。在江汉平原整体景观格局指数的演变上,江汉平原范围内的香农多样性指数由1.0139下降至0.9688,均匀度指数由0.5570下降至0.5407,蔓延度指数由61.8750下降至60.1943,散布与并列指数由55.9097下降至2010年的55.4050,以上数据反映出区域总体的多样性和均匀水平下降,景观异质性降低,各景观类型之间的连接性减弱,不同类型景观之间的接触几率减小。第六章为江汉平原景观格局梯度与环境因子响应分析。通过对江汉平原6种景观的类型指数和整体景观水平指数运用RDA方法进行梯度分析可以发现,地形地貌(平均高程、地形起伏度)、气候(年均降水量、温度季节性)、人口(人口密度)、经济发展(地区生产总值密度)、区位条件(距中心城镇距离、路网密度)等5个方面选取的8个影响因子对各景观类型指数和整体景观水平指数的解释比例最低为79.4%,最高为96.7%,都具有较好的解释效果。对于大部分景观类型,人口密度和地区生产总值强度对景观格局变化的作用比较明显,除建设用地景观外,这两个因子的增加使其他景观类型普遍出现破碎化的趋势；使建设用地景观的面积增加,斑块变大,形状变复杂,也使整体景观格局的多样性减小,不均匀程度上升。年均降水量对水域景观平均斑块面积的影响作用非常明显,并起正向作用,年均降水量增大,水域景观的斑块将变大,同时受人口密度和地区生产总值上升的影响,水域景观斑块个数增加,两者叠加的结果使水域景观面积上升。第七章为江汉平原土地生态安全格局演变与生态保护措施分析。以第四、五、六章的分析结论为基础,对江汉平原区域1987年至2010年以来土地利用数量和结构的变化,土地景观覆被格局的演变对区域生态环境的影响进行了分析,在此基础上对影响江汉平原区域土地生态系统安全状况的因素进行了梳理,并构建了以生态承载力指数、生态稳定指数和生态适应指数构成的土地生态系统安全指数评价体系,在10×10km网格尺度上对江汉平原1987年至2010年土地生态系统的安全状况进行了定量分析。研究发现江汉平原土地生态系统承载力总量减少了40.63×104ghm2,人均生态承载力也由1.17 ghm2下降至0.97 ghm2,反映了江汉平原区域范围内用于生物生产的土地面积呈下降趋势,生态承载力水平和人均生态承载力逐渐降低；同期,江汉平原南部的生态稳定指数下降较大,各网格的平均稳定指数由0.72下降至0.52；各网格的平均生态适应指数由0.56下降至0.41,中南部区域下降的范围最大。1987年至2010年江汉平原区域各网格土地生态系统安全指数的平均值由1.41下降至1.27,土地生态安全状况下降明显；土地生态安全指数的变异程度上升,变化幅度加大,空间关联性下降,空间异质程度上升。在以上分析的基础上将江汉平原范围划分为生态城市优化区、生态综合开发区、生态农业发展区和生态安全控制区四个功能分区,并设定了四个功能分区的主要发展策略,以完善资源配置与利用的方式。同时应大力改善河流、湖泊、湿地的生态状况,积极开展江汉平原区域生态林网的建设,促进区域生态效益、经济效益和社会效益的共同增长。第八章为总结。对本文的主要结论和创新点进行了归纳。更多还原

【Abstract】 Land is the primary natural resource for human survival and reproduction owing to its production and nourishing function, carrying function and ecological service. Land cover means all the land surface elements including natural materials and man-made buildings, which biases towards the land natural attribute. Land use is long-term or periodic human activities according to the land characteristics by means of a series of biological and technical methods in order to achieve a certain economic or social purpose. However, with more and more land demand by human beings, soil erosion, forest degradation, land degradation, desertification, salinization and other environmental pollution phenomena are becoming increasingly serious, meanwhile human also begin to realize that land use and land change as a result are not only simple resource problems, but an important component of global environmental change and its vital reason. Therefore making research into the feedback of land use/cover change on human survival and sustainable development and human’s response mechanism is quite significant in geography.Jianghan Plain is located in south central Hubei, which has the most freshwater lakes in the whole province. From the aspect of regional development strategy, Jianghan Plain is not only a part of Wuhan Urban Agglomeration in the east of Hubei province but belongs to "Yichang-Jingzhou-Jingmen" Urban Agglomeration in the west as well. In addition, Jianghan Plain is also an important part of Yangzi River Economic Belt, so Jianghan Plain has obvious advantage in location and great developing potential in the future. Because of the superior natural geographical condition and long period of agricultural exploitation, Jianghan Plain is the main agricultural production area, grain production area and marketable cotton production base. What is more, depending on the unique distribution characteristics of all the freshwater lakes and wetland, Jianghan Plain is the main wetland ecological area and an ecological barrier for Wuhan Urban Agglomeration, which plays a vital role in protecting the regional environmental quality and ecological security. Due to all the advantages mentioned above, Jianghan Plain becomes quite a special geographical region in China. Now it is subjected to intensive exploitation and utilization and different kinds of external interference, so making a study of the land use/cover change of Jianghan Plain to reveal the change tendency and characteristics of land types in this region, analyzing the factors that influence the landscape pattern of land cover, and evaluating the eco-environmental quality are not only a major field in geography but also have significant practical influence on promoting harmonious development of ecology, population and society.The article is divided into 8 chapters and the main contents are as follows:The first chapter is an introduction, mainly elaborating the research significance of the article. Through colleting and sorting abundant domestic and abroad research materials, including spatial-temporal evolution rule, driving forces, environmental effects, landscape pattern evolution and ecological assessment of land use/cover change, it collates the research progress of land use/cover change and its ecological effects. Meanwhile by summarizing all the related research achievements about Jianghan Plain, it finds out that the present study is analyzing the land use/cover change in just one certain aspect, while comprehensive and quantitative analysis of land use/cover change and its ecological security is quite little in Jianghan Plain since 21th century.The second chapter is the research program. On the basis of the previous study problems mentioned in the first chapter, the objective of this article is to enrich research on the last 20 years’ evolution process of land use and ecological environment and the influencing factors and driving mechanism of landscape pattern in Jianghan Plain to help make reasonable use of land resources, deal with eco-environmental problems, plan and manage ecosystem, and put forward meaningful suggestions to make social economy and eco-environment develop harmoniously and sustainably. Furthermore, the chapter also states the research methods, technical line, study area and the study content that consists of the construction of comprehensive information database of land use/cover change, spatial-temporal change of land use/cover and multi-scale landscape pattern evolution from 1987 to 2010, gradient of landscape pattern in Jianghan Plain and its influencing factors, and land ecological security assessment in study area.The third chapter is about the construction of comprehensive information database of land use/cover change. It applies database technology and GIS to integrate quality and spatial distribution change, landscape pattern change, remote sensing images, digital elevation models, slope, slope aspect, land quality, meteorological statistics, population, economy and social development data of all land types’land use/cover in Jianghan Plain comprising 15 counties about 2823406 hectares in the year of 1987,1995,2000,2005 and 2010. The following content takes the database as foundation.The fourth chapter is the specific analysis of land use/cover spatial-temporal change in study area from 1987 to 2010. By adopting dynamic degree model, integrative index of land utilization, gravity model and land use transfer matrix to analyze the land quantity and spatial distribution change with time, it indicates that farmland is the main land type in the whole study area, most of the farmland’s quality is quite good, water resources are considerably rich and that land is made full use. In the study period, there is great difference of quality change between various land types in different regions. From 1987 to 2010 the area of farmland decreases the most in study area, about 74589.51 hm2, and water area increases greatly, while the lake water tends to decline during these years. In the viewpoint of regional difference, land area changes greater in the east than in the west. In study area mutual transformation between farmland and waters is quite obvious and the area of farmland transformed into waters that are mainly ponds is the largest. In addition, the mutual transformation between farmland, waters and natural reserved land is frequent as well, and construction land is showing a rising trend all the time, which mainly comes from farmland and increases about 12995.62 hm2. At present, serious problems such as farmland greatly reducing, decreasing amount of farmland per person, high demand of construction land, prominent contradiction between land resources and population growth, land utilization efficiency yearly increasing, overload of land resources and ecological land continually declining, especially forest land, waters, natural reserved land bring huge pressure on the regional environment.The fifth chapter is about the multi-scale evolution of landscape pattern. By calculating plaque number, plaque density, average plaque area, area-weighted shape index and area-weighted patch fractal dimension of all types of landscape in study area and 10×10km grid, the result shows that rising plaque number and reducing plaque area of farmland lead to the increasing of plaque density and further irregular plaque shape, and all landscape indices of farmland change greater in the east and southeast than in the west of Jianghan Plain. Forest land, grassland and natural reserved land decrease gradually with time and unevenly distribute in study area, constantly retreating to the west and southwest, meanwhile plaque number reduces, average plaque area enlarges and plaque shape becomes more complex. The plaque number of waters rises, average plaque area declines, landscape fragmentation ascends, plaque shape becomes simpler and the spatial distribution of waters turns out to be continually uneven. The plaque number, average plaque area and plaque density of construction land rises yearly, and the plaque shape complexity increases as well.During the evolution process of landscape pattern in Jianghan Plain, Shannon’s diversity index, Shannon’s evenness index, contagion index and interspersion juxtaposition index respectively declines from 1.0139 to 0.9688,0.5570 to 0.5407,61.8750 to 60.1943 and 55.9097 to 55.4050. The result indicates that landscape diversity and landscape heterogeneity in Jianghan Plain declines under the influence of human beings, which disturbs the landscape connectivity between various land types greatly.The sixth chapter is the analysis of landscape pattern gradient and environmental effects. By applying RDA to analyze the landscape pattern gradient of six different land types and the whole study area, it comes to a conclusion that topography and geomorphology, climate, population, economic development and location all have an effect on landscape pattern evolution, and the lowest and highest explaining rate are 79.4%and 96.7%.For the majority of all land types, population density and gross domestic production play a prominent role in changing landscape pattern. The increase of the two factors will lead to a trend of landscape fragmentation of all land types except that the plaque area of construction land enlarges and plaque shape becomes further complex, meanwhile it also results in declining diversity and increasing unevenness of the whole landscape pattern. Average annual precipitation has an obviously positive effect on the average plaque area of waters, and the plaque area enlarges with more precipitation. Furthermore, under the influence of population growth and gross domestic production development, the increase of plaque number causes the expansion of waters.The seventh chapter is about the evolution of land ecological security and ecological protection measures. Based on the conclusion of chapter four, five and six, it analyzes the change of land quality and structure, evolution of landscape pattern and its effect on regional eco-environment in Jianghan Plain from 1987 to 2010. In addition, it also argues the factors that influence the regional land ecological security and has established a evaluation system from the perspectives of ecological capacity index, ecological stability index and ecological adaptability index to quantitatively evaluate the land ecological security on the scale of 10×10km. The result shows that the capacity of the whole land ecological system declines by 40.63 X 104ghm2, and the capacity per person has decreased from 1.17 ghm2 to 0.97 ghm2, which reflects that the area of land used for biological production is reducing and leads to the current situation. At the same time, the index of ecological stability decreases greatly, and the average stability index in each grid reduces from 0.72 to 0.52. The average adaptability index in each grid decreases from 0.56 to 0.41 and the maximum decrease is in the central south part. During the study period the average land ecological security index declines from 1.41 to 1.27, showing that the land ecological problem becomes even more serious. In addition, the increase variation of land ecological security index reveals the declining spatial correlation and rising spatial heterogeneity between each land types.On the basis of the conclusion above, the article divides Jianghan Plain into four function zones, namely optimizing zone of ecological city, comprehensive ecological development zone, ecological agricultural zone and control zone of ecological security, then proposes development strategy for each function zone to optimize the ways of resource allocation and utilization. For Jianghan Plain, it is of great importance to improve the ecological environment of rivers, lakes and wetland and strengthen ecological forestry construction to promote ecology, economy and society develop together. The eighth chapter is summary. The main conclusions and innovative points are summed up.更多还原