【作者】 王瑞燕；

【导师】 赵庚星；

【作者基本信息】 山东农业大学 ， 土地资源利用， 2009， 博士

【摘要】 当前,人类正以空前的速度、幅度和空间规模影响着全球环境。人们通过土地利用而改变了地表覆被,土地利用/覆被变化则引起诸多自然要素和生态过程的变化,这在生态环境脆弱地区体现得更加明显。因此,土地利用/覆被的环境效应尤其是生态脆弱区的土地利用/覆被的环境效应得到各国科学家的重视,研究“人类驱动力-土地利用/土地覆被变化-全球变化-环境反馈”之间相互作用机制的“土地利用土地覆被变化”(LUCC)成为国际地圈-生物圈计划(IGBP)和全球环境变化中的人文因素计划(IHDP)重要的研究计划之一。而从目前的研究看,多数研究仍侧重于土地利用/覆被的变化,而对其造成的生态环境影响研究则显不足。生态环境脆弱性是生态环境恶化的内因及生态环境重要属性。近年来,随着全球变化而导致的生态环境问题的突显,生态环境脆弱性受到越来越多的关注,国际生物学计划(IBP)、人与生物圈计划(MAB)以及地圈、生物圈计划(IGBP)都把生态环境脆弱性作为重要的研究领域。生态环境脆弱性除受自然环境条件的控制外,人类活动也是影响其变化的重要因素,人类不合理的土地利用方式将会加剧生态环境的脆弱程度。中国的资源环境问题尤为严重,人地矛盾非常突出,同时也是世界上生态环境脆弱区分布面积最大、脆弱生态环境类型最多、环境脆弱性表现最明显的国家之一。加强生态环境脆弱性研究,对环境脆弱区保护、解决生态环境恶化问题和促进人与自然的和谐共处都具有重要意义本研究针对目前环境脆弱性研究领域中存在的主要问题,围绕环境脆弱性评价、时空变化及土地利用对环境脆弱性影响三个问题重点展开讨论。首先,对环境脆弱性的内涵和实质进行了较深入的剖析。在分析环境脆弱性形成机理的基础上,对其进行了定性描述和定量表达。从环境-外界与环境内部组成两个层面上对环境脆弱性进行分析,明确了环境脆弱性的显现条件、实质和特点。基于此,对环境脆弱性的动态演化过程进行了进一步分析并对生态环境脆弱性的基本特性进行系统的归纳总结。其次,进行了县域尺度生态环境脆弱性的动态评价。在对生态环境脆弱性主要属性重新界定基础上,分别从稳定性、敏感性和区域适应性三个方面选取评价指标构建指标体系,建立了评价模型,并对该县1986-2003年的生态环境脆弱性发展变化进行了动态分析。研究结果不仅揭示了1986-2003年期间垦利县生态环境的稳定程度、敏感性和区域适应性的发展趋势,环境自然因子的敏感性分析显示:自然因子的敏感排序结果为地下水埋深>蒸降比>地下水矿化度>气温,确定地下水埋深、蒸降比和地下水矿化度为该区生态环境自然敏感因子。垦利县区域适应性的“障碍度”计算结果表明:盐碱地治理比例始终是第一障碍因素;农田防护林密度的限制集中出现在1995-1998年之间;化肥农药递减率自2000年以后成为主要障碍因素;有效灌溉面积比率和排涝体系面积比例的限制在1990年之前出现。表明了该评价方法可体现出县域生态环境脆弱性的根本原因及其发展变化过程,能反应环境脆弱性多方面特性,对环境决策和管理指导意义更明显。第三,应用熵、突变论等非线性科学理论方法研究了生态环境脆弱性的时空演变。采用信息熵理论对环境脆弱性进行量化表达,借助遥感手段获取数据,设置生态环境样方并计算其环境脆弱度,在此基础上分析了1987-2005年间样方生态环境脆弱性状况。基于突变理论确定了脆弱性发生的时间点和条件,明确了突变的原因和特征;在空间层面,从与黄河和海洋不同距离的两个方向线上,分析了生态环境脆弱性的空间变化规律,结果证明了生态环境脆弱性空间上的渐变性。第四,在分析县域尺度环境脆弱性的动态演变规律和脆弱性发生条件和时间的基础上,从土地利用角度入手,分别采用统计分析和定量方法对LUCC对环境脆弱性的影响进行了研究。首先,通过遥感影像解译获取土地利用信息,并结合垦利县生态脆弱性状况和遥感影像特点,确定地表的植被状况、土壤水分以及地表蒸腾强度为环境脆弱性因子,并以遥感指标表示,通过将其与LUCC进行连接,分析土地利用对环境脆弱因子的影响,得到土地利用类型的环境因子的顺序,在此基础上,根据人类对土地的干扰或利用强度,将土地利用/覆被进一步归类合并,分为不同级别干扰型用地,按面积平差后计算各环境脆弱性因子的值,得到不同干扰度的环境脆弱因子值的计算结果。定量方法的研究又分成两部分进行。一是利用生态位理论度量土地利用对环境脆弱性的影响。结合生态位和生态适宜理论建立了土地利用的环境脆弱性效应的理论框架,在此基础上划分土地生态单元,确定土地利用的需求生态位,计算各单元土地利用的生态环境脆弱效应值。并根据效应值将土地利用的环境脆弱效应划分为四个级别:不脆弱、临界脆弱、轻度脆弱、重度脆弱;二是从土地利用类型的角度,对土地利用/覆被的环境脆弱性效应进行综合评价。在分析土地利用类型对生态环境脆弱性的影响的基础上,构建了包括土地利用类型的空间格局、土地利用类型的生态适宜性和土地利用类型的稳定性等三方面指标构成的评价指标体系。以遥感手段获取土地利用类型信息,层次分析法确定其权重,在此基础上,构建了土地利用类型的空间格局指数模型、土地利用类型的稳定性指数模型以及土地利用生态适宜性指数模型,并进而构建了垦利县土地利用的生态环境脆弱性效应综合指数模型。通过评价,得到了垦利县县域整体和乡镇两个尺度上的土地利用类型生态环境脆弱性综合效应值,系统分析了土地利用类型对生态环境脆弱性的影响及其空间分异。根据评价结果进行了垦利县土地利用的调整分区,提出了各区生态环境建设的措施建议。更多还原

【Abstract】 At present, human being is affecting the global environment deeply at a wide extent and spatial scale, and land use has changed the earth’s surface, which cuased changes in natural key elements and biological process; this effects are especially obvious in vulnerable areas. Therefore, the environmental effects of land use/ cover especially in vulnerable area have gotten more attention. The research on the interact of " human being driving force- land use/ cover change- the global change- environment feedback " becomes one of the important program in the International Humanity Factor Program (IHDP) and the International Geosphere Biosphere Program (IGBP). Up to now, the majority studies still put emphasis on the changes of the land use, while reseaches on the environmental effect of the land use caused by human activities appears insufficient.Environment vulnerability is the internal cause and important attribute of the environment. Ecological environment problems become intense in recent years, so the environment vulnerability catches more and more attention. The International Biology Plans (IBP), the Man and Biosphere Plan (MAB) and the International Geosphere Biosphere Program (IGBP) all take the environment vulnerability as the important field. The environment vulnerability is affected by the natural environmental conditions and the human being activities, and improper land use will be able to aggravate environment vulnerability degree. Chinese resource environment problem is especially severe, the contradiction of person and land is obvious, and china is one of the countries that have the maximum vulnerable area, maximum vulnerability types and the most obvious vulnerability. Therefore, the environment vulnerability study is especially important for preserving the environment and harmonizeing the relation between man and nature in China.Based on the main problems in the environment vulnerability study, this paper mainly discussed the environment vulnerability evaluation, spatio-temporal changes and the land use impacts on environment vulnerability.First, connotation and essence of the environment vulnerability have analyzed. We got the qualitative description and expression of the environment vulnerability based on theist forming mechanism. Environment vulnerability was analyzed from two levels of external comprise and internal environment. The emergence condition, essence and characteristics were ascertained. Owing to that, the environment vulnerability evolvement was analyzed.Secondly, the dynamic changes of environmental vulnerability at county level were assessed. Based on the requirements of environment management, focused on county level, this paper clarified the attributes of environmental vulnerability, selected evaluation indexes from three aspects of stability, sensitivity and applicability, and established the evaluation models, so as to systematically assess environmental vulnerability within county area. The results indicated that the environmental stability of Kenli County was instable, the environmental sensitivity appeared a descend trend and the environmental adaptability showed an uptrend as a whole during 1986-2003. The natural factor sensitivity analysis of Kenli County showed that their sensitivity sequence was that the groundwater level>evaporation and precipitation ratio>groundwater salinity>air temperature. Therefore, the natural sensitive factors of the study area were determined as the former three. The results of obstacle degree of regional adaptability indicated that the saline-alkali soil amelioration rate was the most important obstacle factor during 1986-2003, the restriction of the farmland shelter-forest density mainly appeared during 1995-1998, and the pesticide and fertilization application became the main obstacle since 2000, and the effective irrigation area ratio and the drainage system area ratio raised as the problem before 1990. The conclusions are that the environmental vulnerability of Kenli County is declining, but still in vulnerable state. At the same time, Kenli County should put the emphases on the development of the sensitive and obstacle factors. The assessment method can find the fundamental reasons and the development process of the county environmental vulnerability, which is significant for the current domestic study.Thirdly, this paper utilized the entropy theory and catastrophe theory to study the environmental vulnerability. Spatial-temporal variations of environmental vulnerability in Kenli County of the Yellow River Delta were systematically analyzed through environment samples and remote sensing techniques. Methods of analysis and estimation for the environmental vulnerability catastrophe were established. Our results indicated that the environment of the sample tended to deteriorating during the period of 1987 to 2005, and two catastrophes of environmental vulnerability occurred, one was in 1997, and the other in 2004. Their causes and characteristics were specified accordingly. In addition, spatial variations of environmental vulnerability along two direction lines of different distances to the Yellow River and to the ocean in Kenli County were analyzed, while the results testified the spatial gradual changing pattern of environmental vulnerability. Fourthly, based on the above analysis, this paper analyzed and assessed the impacts of land use on environmental vulnerability in Kenli County focusing on land use types.First, the remote sensing technique was adopted to acquire the land use information, and the vegetation conditions, soil water and surface evaporation were selected as the environmental vulnerability according to the actual situation in Kenli County and the RS image characteristic, which were also expressed by the RS indicators. The impacts of land use on vironmental vulnerability were analyzed through spatial lingking the environmental vulnerability factors and the land use. The vironmental vulnerability factors sequence of different land use type was got. The land use types were classified according to the disturb strength of human. The environmental vulnerability of different disturb degree was calculated by area weights.The quantitative study was divided into two parts, on one hand, the land use impacts to environmental vulnerability was calculated by ecologyical niche. The theoretical framework of land use’s effect to vironmental vulnerability was established according to niche and suitability theories. Based on this, land ecological units were compartmentalized, and the requirement niche of land use was confirmed. Then the unit’s vironmental vulnerability effects of land use were calculated, which were marked into four grades: not vulnerable, verge vulnerable, low-grade and high-grade vulnerable. On the other hand, focused on the land use types, the impacts of land use on environmental vulnerability was assessed, the assessment index system including landscape structure and pattern, land use ecological applicability and land use stability was established. Remote Sensing techniques were adopted to acquire land use information, expert decision method was used for index quantification, and AHP method was adopted for index weight determination. Based on these, the landscape structure and pattern index model, land use ecological applicability index model and land use stability index model were built up, and land use environment vulnerability effect index models were established accordingly. Through assessment, we got the land use environment vulnerability effect index values in two scales of the county and town. Land use impacts on environmental vulnerability and their spatial distribution were discovered. Based on the results, partition of land use adjustment in Kenli County was proposed, and countermeasures of ecological construction in different areas were brought forward.更多还原