陕北农牧交错区土地利用景观动态与优化途径研究

【作者】 郭丽英；

【导师】 任志远；

【作者基本信息】 陕西师范大学 ， 地图学与地理信息系统， 2008， 博士

【摘要】 本文以陕北农牧交错区为例,通过系统分析农牧交错区的发展特点与问题,认为农牧交错带是我国典型的问题区域、重要的生态屏障和国家重大的战略要地,优化区域土地利用结构与布局,是解决目前所面临问题的关键。论文试图在理清北方农牧交错区自然状况与经济发展特点基础上,进一步以地处陕北农牧交错区的榆林市为典型案例,采用遥感、GIS、模型模拟和景观指数分析相结合的方法,进行景观生态类型的划分和景观类型格局变化特征的分析;深入开展典型区域土地利用景观格局动态的模拟研究,测定区域主导的土地利用景观过程;借助于空间相关分析技术,揭示土地利用景观变化的时空格局与驱动机制;探讨实现土地资源可持续利用和区域可持续发展的科学理念与模式,从而为新时期优化调整区域土地利用政策、维护区域及相邻地区的生态安全、探索协调农牧交错生态脆弱区经济发展与生态保护关系的可行途径,提供决策参考依据。论文着眼区域“土地格局变化”和“优化途径”主题,开展了土地利用景观动态及其优化途径的实证研究。主要研究内容包括:1)论述了选题依据及其研究意义,分析了农牧交错区的区域特点及其面临的关键性问题,梳理了相关研究的近今进展;2)探讨了基于遥感信息源与GIS技术的土地类型景观识别、划分标准、定量指标与方法:3)对土地利用景观格局的动态变化进行评价和模拟分析,侧重揭示其时空变动的类型特征及区域差异的规律;4)基于多元回归模型方法,进行了土地利用景观变动的驱动机制分析,探讨了土地利用景观类型转换的主导人文驱动力;5)应用景观生态学原理和专家决策方法,进行了研究区土地利用景观生态设计及其优化途径的初步探讨。论文研究取得以下主要进展和结论:(1)陕北农牧交错区是生态脆弱、资源富集、乡村贫困的特殊区域,实现资源、生态、经济和社会的协调与可持续发展,具有十分重要的现实意义。在系统梳理相关研究成果与进展,以及土地利用景观动态研究的理论与方法的基础上,将“土地格局变化”和“优化途径”作为论文研究的主题,梳理提出了陕北农牧交错区域4个方面的突出特点,即生态脆弱性、要素复杂性、矛盾尖锐性、变化频繁性。(2)土地利用景观的类型结构及其空间分异,受区域尺度大小的深刻影响,采用多尺度分析有利于深入揭示土地利用景观格局的形成机制、演化规律及优化途径。论文根据研究对象及其尺度的不同,建立了榆林市全区、北部风沙滩区和横山典型县域等不同尺度区域的系列土地利用遥感影像数据库及其社会经济数据库。将榆林市土地利用景观类型划分为6个一级类、20个二级类;在县域尺度上结合应用SPOT5高分辨率遥感影像,将横山县土地利用景观类型划分为6个一级类、25个二级类。并借助于GIS技术与景观格局分析法,可实现对不同尺度的土地利用景观类型特征、结构格局及其动态变化时空差异性的模拟与分析。(3)区域土地利用景观变化受自然、经济、社会和技术等因素的综合影响,深入理解和深刻揭示这些因素变化特征、影响机理与作用模式,是全面认识区域土地利用动态、人文驱动机制及其社会经济效益等多方面复杂系统问题的重要前提.论文以榆林市1985、1995、2003年三期Landsat TM遥感影像的解译结果为基本信息.研究发现草地与耕地类型互转的“大进大出”,是本地区土地利用景观变化的重要特点,也反映出农用地利用粗放与管理无序的问题。总体而言,1985-2003年的土地利用景观破碎度增大、景观多样性增高,以及景观类型的分离度差异明显,表明陕北农牧交错区的土地利用的人类活动增强,土地景观类型退化的趋势尚未得以扭转。(4)土地沙漠化是陕北农牧交错地区土地利用景观动态变化的主要自然过程之一。特别是其中的陕北长城沿线地区,由于自然环境本身的脆弱性,再迭加近20多年来地区能源矿产资源开发、工业园区建设等人类经济活动的强烈作用,其土地利用景观类型格局发生了显著的变化,尤其是诱发了土地沙漠化的严重发生,土地退化程度不断加剧。土地沙漠化景观类型质心分布向西南、东北方向的扩展,严重威胁着西南部和东北部黄土区的生态安全。总体而言,该地区土地利用景观发生变化的部位主要在南部定边、靖边县境内的低山丘陵区,以及毛乌素沙漠边缘地带和东南部黄土丘陵沟壑区。(5)区域土地利用景观格局的形成和演化,是自然因素和人文因素共同作用的结果,其中人类经济活动的影响具有主导作用。榆林市土地退化与人口压力增大、过度土地利用等有直接关系,而人类不合理的土地利用是土地退化的主要诱发因素,其实质也是由于当地人口的过快增长、农牧业技术相对滞后和土地承载力不协调的深层次矛盾所造成的。1985-2003年,榆林市治沙种草与造林对土地利用类型转换贡献率为74.55%,其主要转换方式是未利用地转向草地和林地;农业结构调整贡献率为11.85%,主要是耕地转向草地、林地与草地;土地退化贡献率为6.48%,表现为草地、耕地、林地与水域转向未利用地;开垦耕地贡献率占4.05%,表现为草地、未利用地、林地与水域转向耕地。(6)陕北农牧交错区土地类型景观优化的根本途径,在于科学协调区域人地关系,实现资源、生态、经济、社会的有机统一和良性循环。该地区土地利用景观生态设计应突出体现“三性”,即景观生态规划与可持续发展目标的一致性,景观生态设计与土地利用规划的协调性,景观生态格局与土地利用模式的耦合性。论文分别从专家决策支持、景观类型分异的视角,具体研究了土地利用景观生态设计及优化的模式和途径。论文研究力求在以下4个方面有所创新:(1)论文注重理论分析与实地观测、调研相结合,定性与定量相结合,模型分析与专家辅助决策相结合,成果应用、理论总结与模式归纳相结合,充分利用遥感与GIS技术、数据模型与景观指数分析等量化方法综合集成的优势,并且注重着眼于从榆林市域.北部长城沿线地区-横山县等三种空间尺度,开展土地利用景观类型格局、动态与机制的深入研究,揭示土地利用景观格局变化的尺度差异与效应,拓展了土地利用/覆被变化研究的理论与方法。(2)着眼于北方农牧交错带的区域问题、战略地位和持续发展的实证分析,重点以地处农牧交错区的陕北榆林市为典型案例,面向陕北农牧交错区“土地格局变化”和“优化途径”两个主题,围绕数据采集与建模→土地景观类型划分→土地景观格局动态分析→土地景观变化机制模拟→土地利用景观生态设计与优化途径这一主线组织论文研究。(3)重视新技术应用与模型开发。以榆林市为例,建立了土地利用景观分类体系,试图构建从TM遥感影像直接测定土地利用景观类型及植被盖度变化等特征量和诊断土地利用景观动态的数理分析模型。通过“3S”技术集成,将纠正过的多时相影像数据进行GIS管理,开发自动采集影像信息用于监测和评估土地利用类型格局时空变化规律的指标体系与技术方法;实现土地利用类型动态信息格网化,并借助空间相关分析,揭示土地利用类型景观变化同主导的自然与社会经济因子的关系,进而实现对土地利用类型景观动态评估及其分析。在多信息源利用、多模型方法集成方面取得了新进展。(4)瞄准区域决策实践目标。基于对研究区土地利用景观动态变化的分析及其主导的人文传导机制的认识,按照统筹人与自然和谐发展的理念和要求,着眼陕北农牧交错区域、北部风沙滩区与南部黄土丘陵区、横山县等不同的尺度及其土地利用景观结构的差异,面向区域可持续发展目标,深入开展土地利用结构调整与优化布局的实证研究。充分利用景观生态设计的原理、循环经济的理论和统筹协调决策的方法,开展了陕北农牧交错区土地利用景观生态设计及其优化途径研究,提出促进农牧交错区土地可持续利用和实现区域可持续发展的策略及政策性建议。更多还原

【Abstract】 Taking northern Shanxi as an example, this paper analyzed the characteristics and problems in the development of the interlocked zones of farming and grazing, and pointed out that the interlocked zones of farming and grazing are typical areas with problems, vital ecological barriers and important places for the nation’s overall consideration in China, and optimizing its land use structure and arrangement is the key point to solve the problem confronted. Furthermore, taking Yulin City which is located in the interlocked zones of farming and grazing of northern Shanxi as the study object, it divided landscape types and analyzed the characteristics of landscape change by methods of remote sensing, GIS, modeling and landscape index; indentified the dominant processes of regional land use change by modeling the landscape trends; uncovered the spatio-temporal patterns and driving forces of land use change with the aid of spatial analysis; discussed the strategies and patterns of sustainable land use and sustainable regional development, aiming to assist the decision-making for adjusting the land use policy, maintaining the ecological safety and exploring approaches to balanced relationship between development and conservation in the interlocked zones of farming and grazing with fragile ecology.The topics of this paper are land use change and approaches for optimal land use, and the main aspects of the research are: 1) discussing the inducement of the topics and the meaning of the research, analyzing the characteristics and key problems of the interlocked zones of farming and grazing and reviewing the corresponding references; 2) discussing the criterions, indexes and methods of landscape identification and classification on the basis of remote sensing and GIS; 3) appraising and stimulating the land use change process and uncovering the spatio-temporal characteristics of the types and the rule of regional differences; 4) analyzing the driving mechanism and the dominant humanistic driving forces of land use change by the model of multiply regression; 5) studying land ecological design and approaches to optimal allocation under the guide of the landscape ecological theory by expert decision-making.The conclusions of this research are summarized as follows:(1) The interlocked zones of farming and grazing of northern Shanxi is a different region with fragile ecology, rich resources and rural poverty, hence its harmony of the resources, ecology, economy and society and sustainable development are provided with vital realistic meanings. On the basis of research advance and the theory of landscape study, taking land use change and approaches for optimal land use as the topics, this paper characterized this region with fragile ecology, complex elements, sharp conflicts and frequent changes.(2) The type structure and spatial differentiation of landscape is greatly influenced by the scale of the region, hence multi-scale analysis benefits to uncover the formative mechanism, evolutional rule and approaches for optimization. This paper established the land use databases and socio-economic databases on the scales of Yulin City, northern blown-sand area and Hengshan County respectively. The landscape in Yulin City was divided into six first-grade types and twenty second-grade types and in Hengshan County was divided into six first-grade types and twenty-eight second-grade types using high-resolution remote sensing image of SPOT5. With the aid of GIS and analysis of landscape pattern, the landscape characteristics and structural pattern were analyzed and the changes and their saptio-temporal differences were stimulated on different scales.(3) Regional landscape change is influenced by nature, economy, society and technology synthetically, and uncovering the change, the effect and the functional mode of these elements is the precondition to completely understand land use change and its humanistic driving mechanism and socio-economic benefits. Based on the TM data from three remote sensing images of 1985,1995 and 2003, it was found that the intense mutual conversion between grassland and cultivated land was a significant trait of land use change in this area, which also reflected the extensive utilization and out-of-order management of agricultural land. As a whole, the increasing landscape fragmentation and diversity and the obvious difference of landscape isolation in the period of 1985 to 2003 has shown that the human land use activity in the interlocked zones of farming and grazing of northern Shanxi has intensified and the trend of landscape degradation has not been retorted.(4) Land desertification is one of the major natural processes of land use change in the interlocked zones of farming and grazing of northern Shanxi. Especially in the areas along the Great Wall, great landscape changes have happened and induced serious land desertification and increasing land degradation because of its fragile ecology and intensive human activities such as mining and industrial park construction in the recent decades. The centroids of land desertification expand to the southwest and northeast threatened the ecological safety of the southwestern and northeastern. In a word, the changes area of land use landscape mainly is in southern Dingbian, the hilly areas in Jingbian, as well as Maowusu Desert area and south eastern Loess Plateau area.(5) Formation and evolution of regional land use landscape patterns are the common results of natural and human factors, and the later plays a leading role. Land degradation of Yulin city has a direct relationship to increasing population and excessive land use, and human irrational land use is the main factor, in which the essential is a disharmony caused by excessive population, relatively backward agricultural technology and land capacity. From 1985 to 2003 in Yulin City, the contribution rate is 74.55% from afforestation and grass to land use type conversion, in which the main conversion is unutilized land to grassland and woodland; the contribution rate of structure adjustment is 11.85%, in which the main conversion is farmland to grassland and woodland; the contribution rate of land degradation is 6.48%, in which the main conversion is grassland, farmland, woodland and water area to unutilized land; the contribution rate of farmland reclaim is 4.05%, in which the main conversion is grassland, unutilized land, forest land and water area to farmland.(6) The fundamental approach of optimizing landscape in interlocked agro-pasturing area of northern Shaanxi is coordinating regional human-land relationship, which can realize virtuous circle among resource, ecology, economy and society. The land use landscape in this area should be designed to highlight ’Three Characters’, which embodies consistency between landscape ecological planning and objectives of sustainable development, coordination between landscape design and land-use planning, coupling between landscape patterns and land use patterns. From viewpoint of expert decision support and landscape types differentiation, this Paper also studies models and approaches on land-use landscape design and optimization.Innovations of the study are as follows:(1) Combines theory with practice, qualitative with quantitative, models with experts assistant, this paper makes full use of remote sensing and GIS technology, data models and landscape analysis, etc. And focused on the spatial scales of ’Yulin city - the northern region along the Great Wall - Hengshan country’, this paper studies land use pattern of landscape types, dynamics and mechanism, which reveals the scale differences and effects of landscape pattern and spreads the theory of LUCC.(2) Focus on Yulin’s demonstration of regional issues, strategic position and sustainable development in interlocked agro-pasturing area of north China, ’data collection and modeling→landscape classification→dynamic analysis of land pattern→mechanism simulation of landscape change→landscape design and optimization’ is organized as a mainline, which faces to ’land pattern changes’ and ’optimization approach’ in interlocked agro-pasturing area of northern Shaanxi.(3 )This paper emphasis on new technology applications and models development. As a case study of Yulin city, it establishes classification system of land use landscape, and builds characteristics of determining land use landscape types and vegetation cover changes from TM remote sensing images, which also diagnoses dynamic changes of land use landscape. Through ’3S’ technology integration, the paper realizes GIS imaging data management which is rectified. And it develops index systems and technical methods for monitoring temporal and spatial variation of land use pattern. By space-related analysis, it achieves dynamic information grid of land use types, and reveals the relationship between changes of landscape and natural-social-economic factors. So it makes great progress on use of information sources and integrated multi-models approach.(4)This paper targets regional targets of decision-making and practice. Based on understanding to regional land use dynamic changes and its human transmission mechanisms, this paper studies demonstration of land use structure restructuring and layout optimization, that are oriented to different scales of ’interlocked agro-pasturing area of northern Shaanxi, floodplain sandstorms in northern Shaanxi, southern Loess Hills area and Hengshan country’. And through making full use of principles of landscape design, economic cycle and coordinated decision-making theory, this paper studies land use landscape design and optimization approach, and at last brings forward strategy and policy of promoting sustainable land use in interlocked agro-pasturing area.更多还原