【作者】 杨世伟；

【导师】 杨新民；

【作者基本信息】 西北农林科技大学 ， 水土保持与荒漠化防治， 2003， 硕士

【摘要】 区域水土保持规划指标体系的建立及其模型的研究是水土保持规划的一项基础性工作，是进行水土流失综合评价及水土保持生态环境建设的前提条件和基本途径。它对于做好水土保持规划，因地制宜地防治水土流失具有十分重要的作用和意义，尤其对于水土流失极其严重的黄土丘陵区来说更有其研究的必要性和紧迫性。 本研究立足于黄土丘陵区，以小流域为研究单元，系统分析了以往对该区水土流失规律的相关研究成果，在水土流失评价指标的筛选、指标权重的确定、指标的量化以及评价模型的建立等方面进行了一定的探索。并在上述研究的基础上，对县南沟流域水土流失与水土保持现状进行了综合评价，分析了其生态环境建设中存在的主要问题，指明了治理方向。主要的研究结果如下： (1)针对黄土丘陵区的区域特征，综合考虑自然和社会经济因素对水土保持的贡献作用和作用程度，并在科学性、可操作性、独立性、层次性、动态性原则的指导下，建立了一套可用于水土保持综合评价及动态监测的指标体系。该指标体系共涉及了气象、土壤、地形、植被、土地利用、经济人口方面的6大类15个具体指标。 (2)采用层次分析法对规划指标进行了赋权计算，层次总排序结果显示，黄土丘陵区水土保持的主要制约因子为坡耕地比例(权重0.244)、植被覆盖率(权重0.18)和平均坡度(权重0.116)，从而在一定程度上反映了国家在该地区实行退耕还林还草政策的正确性。 (3)通过对黄土丘陵区水土流失规律的深入分析，为避免分级评分的跳跃性，借助模糊数学理论，分别建立了各规划指标对区域水土保持综合指数的贡献函数，从而实现了指标的量化。在此基础上，采用模糊加权综合指数法，建立了以水土保持综合指数为评价结果的区域水土保持综合评价模型。此外，为帮助研究者进一步发现区域水土保持生态环境建设中存在的问题，进而指导水土保持规划方案的合理制定，引入了评价因子匹配系数的概念。 (4)利用所建立起来的区域水土保持规划指标体系和模型，对县南沟流域的水土保持状况进行了综合评判，其水土保持综合指数为0.5390。通过因子匹配系数的计算，说明县南沟流域的植被状况相对较好，造成水土保持水平不是很高的主要原因是其地形破碎、地面坡度大，而人为土地利用的不合理更加加剧了这一后果，大量的坡耕地是产生水土流失的主要根源。根据县南沟流域水土流失与水土保持现状，提出了其水土保持规划的基本原则。更多还原

【Abstract】 Study on index system and model is a basic job for soil and water conservation planning. It is also the prerequisite and basic approach of soil and water loss comprehensive assessment and soil and water conservation ecological environment construction. It is very important and significant for making a good soil and water conservation plan, and choosing suit measures to prevent soil and water loss according to the local conditions, especially in loess hilly region.Taking the loess hilly region as its object, choosing small watershed as its unit, the study systematically analyzes the previous correlative results about soil and water loss rules. The author makes an effort in how to choose indexes, how to define weight, how to quantify the indexes and how to establish a model. Based on the above study, the author synthetically appraises the soil and water loss situation of the Xiannangou watershed, and analyzes the main problem in its ecological environment construction, and point out the harnessing ways. The main results are listed as follow.1. According to the features of the loess hilly region, the nature and society factors are considered comprehensively and a set of index system, which can be used in soil and water conservation assessment and dynamic monitoring, is established following the principles of science, operation, independence, level and dynamic. The index system includes 15 indexes related to climate, soil, landform, vegetation, land utilization and economy population.2. Adopt AHP to calculate the weight of indexes. The result indicates that the main resisting factors of soil and water conservation in loess hilly region are ratio of slope farmland (weight 0.244), vegetation coverage (weight 0.18) and average slope degree (weight 0.116). It reflects the correctness of returning the dry upland to forest or grass land.3. By analyzing deeply the rules of soil and water loss, the contribution functions are set up to realize the indexes’ quantification with the help of fuzzy mathematics theory. Based on this, the regional soil and water conservation comprehensive assessment model is established. In order to help the researcher find out the existing problems in soil and water conservation ecological environment construction, the commensurate coefficients are introduced here.4. Using the index system and model, the author assesses the soil and water conservation situation of Xiannangou watershed. Its index of soil and water conservation is 0.5390. The commensurate coefficients show that the vegetation condition is relative good, but its broken landscape, big slope degree, and irrational utilization of land, especially mass slope farmland,are the main causes of soil and water loss. Hereby the principles of soil and water conservation are put forward.更多还原