【作者】 付光辉；

【导师】 刘友兆；

【作者基本信息】 南京农业大学 ， 土地资源管理， 2007， 博士

【摘要】 土地是人类赖以生存的最基本的生产和生活资料，随着经济社会的迅速发展和城市化进程的加快，耕地这一重要的生产资料正受到了不断的蚕食，耕地保护形势日益严峻。为了实现耕地总量动态平衡的目标，保障粮食安全，土地整理正成为一项重要战略手段。然而，土地整理毕竟是借助于一系列的生物措施和工程措施，对田、水、路、林、村进行的综合整治，在此过程中不可避免地会对项目区及周边地区的水文、土壤、植被、大气、生物等环境要素及其生态过程产生诸多直接或间接的不利影响(即生态风险)。在土地整理中引入生态风险评价，找出土地整理中可能产生的不利生态效应，并评定其危害的大小及范围，对土地整理过程中规避生态风险、构建生态环境友好型土地整理模式具有重要的理论意义和现实意义。文章在总结已有的土地整理生态评价和生态风险评价案例的基础上，面向土地整理生态管理的要求，将生态风险评价理论与方法引入土地整理环境影响评价领域，开展了土地整理生态风险评价原理、程序和方法等方面的研究，形成了比较完整、系统的土地整理生态风险评价理论与方法体系。具体来讲，本文主要进行了以下几方面的研究：(1)应用景观生态学原理分析了土地整理与生态环境之间的关系，研究了土地整理干扰的景观动力学原理和过程，构建了土地整理工程所引起的景观变化遵循的“驱动因子—景观变化—生态影响”模型，从而揭示了土地整理对整理区域的景观生态影响途径和效应，不仅为构建风险源与风险受体接触暴露关系的概念模型奠定了基础，也对土地整理生态评价和保护具有积极意义。(2)土地整理生态风险评价步骤可概况为：问题描述与形成、受体分析与生态终点选择、风险源分析、概念模型与分析计划、暴露—危害分析、风险表征、不确定性分析以及风险管理等8个部分。其中，土地整理生态风险源可归纳为土地平整、植被破坏、沟渠路建设与零星地块的归并、作物种植与客土填充以及大规模土地开发中的居民点兴建与扩张；概念模型用于揭示风险源与风险受体接触暴露关系；暴露—危害分析可主要针对土地整理区微地貌、土壤性状、水环境和生物、生境与景观4个方面展开；风险表征即评估危害作用的大小以及发生的概率的过程，是风险评价的核心部分，目前主要有两种分析模型：综合指标评价模型、相对风险模型(RRM)；不确定性研究采用当前国际上应用较为广泛的定量分析方法——蒙特—卡洛模拟法(Monte Carlo Simulatio)展开，探索性的研究了生态风险评价过程的不确定性来源及评价方法；风险管理是土地整理生态风险评价的一个必要步骤，它依据风险表征的结果，提出合理的风险管理措施，以实现研究区土地整理风险的最小化。(3)本文提出了适用于土地整理项目和资料较全面的土地整理区域的综合指标评价模型，从土地整理对自然系统的影响、对生态系统功能的影响和对景观格局的影响等3个方面构建了土地整理生态风险评价指标体系。综合指标评价模型中可用于风险表征的定性与定量方法包括：层次分析法(AHP)、模糊综合评判、灰色评价模型、敏感因子模型和定性分析推理(专家系统)等。综合指标评价模型按照“成因机制分析→风险小区划分→敏感因子分析和定性分析推理→数学模型分析→综合评价”这样一个综合运用流程进行。文章应用综合指标评价模型对大丰市沿海滩涂开发项目进行的实证研究，将草滩地、苇地、滩涂、坑塘与鱼虾塘、河流沟渠(包括河流、水渠)和居民点作为风险受体，构建了一系列指标形成生态终点集，通过上述流程和方法进行评价。结果表明：该评价模型通过了蒙特—卡洛模拟法的不确定性检验，证实了综合指标评价模型对土地整理项目生态风险评价具有很强的适用性。实证研究还将沿海滩涂开发区域分为5个风险等级：高风险区(Ⅰ级)，面积占研究区总面积的21.20％；较高风险区(Ⅱ级)，占5.58％；中等风险区(Ⅲ级)占70.07％：低风险区(Ⅳ级)占1.62％；弱风险区(Ⅴ级)占1.53％，并针对不同的风险等级提出了生境调整等风险管理措施。(4)本文还将国外新近提出的相对风险模型(RRM)引入到土地整理生态风险评价中。为了降低区域风险评价中的不确定性，改进了RRM模型中不同区域间压力源和生境相对密集度的确定方法，将原有的分段赋值法改进为比值法，使原来离散的密集度等级值变为连续的分值，实现了区域内不同评价小区间风险程度的比较。RRM模型的评价结果表征了不同评价小区间相对风险关系，因此适用于资料相对贫乏区域的评价。文章应用RRM模型开展大丰市域土地整理生态风险评价时，选择物种多样性、生境质量和景观格局分布作为评价的生态终点，构建了大丰市土地整理区风险源—压力—生境变化—生态终点的暴露和响应路径的暴露模型，在表征土地整理压力与评估的生态终点之间的暴露和响应时，引入了“压力密度”和“生境丰度损失”的概念。通过综合计算区域风险源的压力密度、生境丰度损失、暴露系数和响应系数之积，针对不同风险源类型、不同生境变化、不同生态终点、不同风险小区计算出潜在风险的风险值。实证研究表明：大丰市东部大部分是土地开发区，虽然有效耕地增加较多，但生态风险较高；中部大部分属于中等风险区和低风险区；西部主要耕地整理区和废弃地复垦区，属于弱风险区，应成为大丰市土地整理的首选区域。相对风险模型虽然所表征的生态风险关系是一种相对风险关系，但同样能实现对区域采用分级系统对评价小区内的各类风险源及生境进行的等级评定。大丰市域土地整理生态风险评价结果不仅通过了蒙特—卡洛模拟法的不确定性检验，也与实地调研结论吻合较好。(5)本文不仅提出了不同风险等级小区的降低生态风险的对策，还针对研究中发现的土地整理主要生态风险，提出了规避生态风险的政策建议，包括：①适度开发未利用土地，加大耕地整理、废弃地复垦的力度；②对湿地等重要生态资源的开发，应进行生境调整；③应用土地整理项目的景观生态规划设计，开展景观生态型土地整理；④建立土地整理生态环境评价体系，适度发展生态农业。全文共分五大部分，各部分内容如下：第一部分为第1章导论，主要提出了本文研究的目的意义、内容、论文结构、技术路线和所采用的分析方法等内容；第二部分包括第2和第3章的内容，主要介绍了生态风险评价与土地整理生态问题研究的进展与研究方法、土地整理生态风险评价的相关基础理论；第三部分含第4、第5和第6章，主要包括土地整理生态风险评价概念、原理；土地整理与生态环境关系的景观生态学分析；土地整理生态风险评价程序、模型与方法。第四部分包括第7和第8章，分别以大丰市沿海滩涂开发项目和大丰市域为研究对象，应用综合指标评价模型和相对风险模型(RRM)进行的实证研究。第五部分内容为第9章，是全文主要结论和对策建议。更多还原

【Abstract】 Land is human basis of produce and maintenance materials. Along with the explosive growth of economy and society and the accelerating of urbanization process, cultivated land-the important means of production is getting unceasing nibble, and the situation of cultivated land protection becomes increasingly grim nowadays. In order to carry out the aim of the total cultivated land dynamic equilibrium and ensure grain safety, land consolidation is becoming important grand strategy. However, with the aid of a series of biological measure and engineering measures, field, water, road, forest and village are comprehensively renovated, land consolidation brings many direct or indirect harmful influence (ecological risk) inevitably for ecological course and the environmental essential factors such as hydrology, soil, vegetation, atmosphere and biology of project district and its background area .The purpose of introducing ecological risk assessment regime into land consolidation is to find out the possible, disadvantageous ecological effect, and assess the scope and size of its harm. The research has important theoretical meaning and realistic meaning for avoiding ecological risk and founding the ecological environmentally friendly land consolidation pattern.On the basis of summarizing existing resources of ecological assessment of land consolidation and ecological risk assessment, and facing the appeal of ecology management, the paper introduces theoretic and methods of ecological risk assessment into the domain environmental impact assessment of land consolidation. The principium, program and methods of ecological risk assessment of land consolidation are carried out, and complete, systematic theoretic and methods system of ecological risk assessment of land consolidation is formed. This paper has carried out the research of following few aspects mainly.(1)Applying landscape ecology principle, this paper analyses the relation between land consolidation and ecological environment. Landscape principle of dynamic and process disturbance of land consolidation is studied; driving factor -landscape change-ecological influence model followed by landscape change that aroused by land consolidation is carried out; approach and effect of landscape ecological impact in land consolidation area is analyzed. The analysis of the relation between land consolidation and ecological environment is the basis of building conceptual model of contiguity and exposure relation between risk source risk and risk receptor, and has positive meaning for ecological risk assessment of land consolidation and ecology protect.(2) This paper founds theoretical frame of ecological risk assessment of land consolidation and has discussed risk assessment process in detail. Ecological risk assessment of land consolidation includes eight steps: problem plans and forms, receptor analysis and ecological endpoint choosing, risk source analysis, conceptual model and analysis plan, exposure-hazard analysis, risk characterization, uncertainty analysis, risk management. In which land consolidation ecological risk source can be summed up: land leveling, damage of vegetation, channel and road construction and scramble parcel merging, crops implant and incorporation with extra soil, residential area constructing and dilatation along with massive land development. Conceptual Model reveals and describes the relation of exposure and respondence between risk resource and receptor. Risk characterization is the course of evaluating the size of harm role as well as the probability that occurs, it is the key part of risk appraisement, and now there are two analysis models mainly: comprehensive index model and relative risk model (RRM).Exposure-hazard analysis can mostly aim at the 4 aspects: micro topography, soil properties, water environment and Organisms, habitat, landscape. The quantitative analysis method -Monte Carlo Simulation that applied extensively currently is adopted for uncertainty analysis, and the tentative research including uncertainty source and assessment technique in the course of ecological risk assessment of land consolidation is expanded. As a necessary step of ecological risk assessment, according to the result of risk characterization, risk management puts forward reasonable risk management measure in order to minimize the ecological risk of land consolidation.(3) This paper has discussed the comprehensive index assessment model that applies to land consolidation project or land consolidation area that has major information. According to the influence for natural system, ecosystem function and landscape of land consolidation, index system of ecological risk assessment of land consolidation is carried out. This paper has also put forward the many methods for risk characterization such as analytic hierarchy process, the fuzzy comprehensive evaluation, the gray evaluation model, sensitive factor model, qualitative analysis and consequence. And the general application flow that is "contributing factor- machine made analysis→risk sub-district partition→sensitive factor analysis and qualitative analysis and consequence→mathematical model analysis→comprehensive valuation" is developed. Then, applying comprehensive index model, empirical research of coastal mudflat development project ecological risk assessment in Dafeng County is done. Grass beach area, reed ground ,mudflat, tunnel and pool, river and channel, resident point are regarded as risk receptor at coastal mudflat development project ecological risk assessment in Dafeng County. Following the above mentioned flow and model, risk grades of different assessment sub-districts is determined. This assessment result has passed the uncertainty inspection of Monte Carlo Simulation, so that it is successful to apply comprehensive index assessment model in land consolidation project ecological risk assessment. Appraisal results of coastal mudflat development project ecological risk assessment in Dafeng County shows: coastal mudflat development project district can divide into 5 risk grades: High sub-district (Ⅰlevel), area takes 21.20% of project district; Higher sub-district (Ⅱlevel) take 5.58%; Medium sub-district (Ⅲlevel) take 70.07%; Low sub-district (Ⅳlevel) to take 1.62%; Weak sub-district (Ⅴlevel) take 1.53%.And according to different assessment risk grade, the risk management measures such as habitat adjustment is put forward.(4)The relative risk model (RRM) that was developed abroad recently is introduced into ecological risk assessment of land consolidation. In order to reduce the uncertainty in regional risk assessment, the definite method of relative dense degree between different area risk pressure source and habitat is ameliorated, and intrinsic fragment assignment law is substituted using ratio method, so original discrete intensity rank is converted to consecutive point value, and the comparison of risk level between different sub-districts is actualized. The assessment result of RRM model indicates the relative risk relation between different assessment sub-districts; therefore apply to the region ecological risk assessment with relatively less information. Applying RRM, ecological risk assessment of land consolidation in Dafeng County is done. Species diversity, habitat quality, landscape pattern are regarded as ecological endpoint. Though conceptual model of exposure and respond route between risk source, pressure, habitat change, ecological endpoint, the paper introduces two indexes: pressure density, habitat abundance loss into reckoning the degree of exposure and respond between pressure and ecological endpoint. Finally through comprehensive product of pressure density, habitat abundance loss, exposure coefficient, respond coefficient, the latent risk value according to different risk source type, different habitat change, different ecological endpoint and different risk sub-districts is reckoned. Empirical research shows: East in Dafeng County is land developing zone mostly, though, effective cultivated land is more, but ecological risk is higher; Central section belongs to medium risk sub-district and low risk sub-district mostly; West is cultivated land consolidation zone and abandoned land zone, and belongs to weak risk district, so West should become first selection area for land consolidation. Though relatively risk model shows a kind of relatively risk relation between risk sub-districts, it also can realize the grade assessment between each kind of risk source and habitat of different risk sub-districts. The result of region ecological risk assessment of land consolidation has not only passed the uncertainty inspection of Monte Carlo Simulation also coincides with the conclusion from field survey.(5)This paper, not only, according to deferent level appraisement sub-district, has put forward the countermeasure that reduces ecological risk, but also has made the policy suggestion of avoiding ecological risk. The suggestion includes:①developing appropriate unused land, increasing cultivated land consolidation and abandoned land consolidation;②habitat adjustment is necessary because of developing important ecological resource such as wetland;③applying the landscape ecological program and design of land consolidation project, carrying out landscape ecological type land consolidation;④establishing land consolidation appraisement system of ecological environment, developing environmental-friendly agriculture appropriately.The paper is divided into five parts. The first part, including chapter 1, focuses on the objective, content, research framework, technical route and the analysis method etc. the second part, including chapter 2-3, focuses on the advances in researching ecological risk assessment and ecological problem of land consolidation and the basic theories for ecological risk assessment of land consolidation. The third part, including chapter 4-6, focuses on, the relation analyses between land consolidation and ecological environment, as well as the concept, program, model and method of ecological risk assessment of land consolidation. The fourth part, including chapter 7-8, focuses on the empirical study. Based on comprehensive index model and relative risk model (RRM) differently, empirical research of coastal mudflat development project ecological risk assessment in Dafeng County and ecological risk assessment of land consolidation in Dafeng County are done. The fifth part, including chapter 9, focuses on the main conclusion and relative countermeasures and suggestions for avoiding ecological risk.更多还原