藏东横断山区典型小流域水土流失量预测模型研究
文献类型：学位论文
| 作者 | 辜世贤 |
| 学位类别 | 博士 |
| 答辩日期 | 2009 |
| 授予单位 | 中国科学院水利部成都山地灾害与环境研究所 |
| 授予地点 | 成都 |
| 导师 | 刘淑珍 |
| 关键词 | 土地利用 137Cs示踪法 遥感监测 通用流失方程 治理模式 |
| 其他题名 | The study on the soil erosion prediction model in the typical watershed of Hengduan mountainous region in the Eastern Tibet |
| 学位专业 | 自然地理学 |
| 中文摘要 | 矮西沟小流域位于藏东横断山区，是金沙江上游一级支流。该区为高山峡谷地貌，金沙江既是我国拟开发的最大水电基地之一，又是产沙量最多的河流。矮西沟小流域水土流失严重，直接影响到金沙江水环境安全。前人对藏东昌都地区金沙江流域水土流失过程规律研究不多。因此，开展昌都地区江达县矮西沟流域水土流失预测模型研究意义重大。本研究从土地利用与水土流失的关系调查入手，运用RS、GIS、137Cs等技术和景观格局分析新方法，分析研究区水土流失特征，建立藏东横断山区典型小流域的水土流失预测经验模型，并对模型进行验证和应用，取得了以下研究结果： (1)研究区主要侵蚀类型为水力侵蚀，低覆盖度草地和坡耕地为严重侵蚀类型。海拔高度与侵蚀类型关系密切。侵蚀强度与土地利用空间结构和坡度密切关系。针叶林地和低覆盖度草地是研究区的优势主导景观；疏林地、低覆盖度草地破碎度大，有加剧侵蚀的趋势；水系、中覆盖度草地的边缘效应大，是水力侵蚀与其他类型侵蚀交错区；草地转化耕地和中覆盖度草地的景观异质性指数大，侵蚀强度大。 (2)以RUSLE模型为基础，初步建立了研究区土壤侵蚀预测评价模型。根据对研究区土壤侵蚀特征的研究及查阅大量前人研究成果，确定模型中侵蚀因子：R值选用指数函数；K值采用RUSLE模型的估算法；LS因子的估算根据不同的坡度等级进行分段估算；C值的估算以植被覆盖度为依据；P值的研究相对较少，根据对研究区的调查，采用梯田固定为0.03。经计算整个小流域的土壤侵蚀平均模数值为4391.72t/km2.a。检验表明：土壤侵蚀强度空间分布与野外调查一致；模型法估算的全流域侵蚀强度分级更为均匀；对于草地和坡耕地的平均侵蚀模数预测模型估算值与137Cs示踪法估算值相接近。因此，本研究建立的模型对藏东横断山区典型小流域的土壤侵蚀量的估算结果具有一定的可靠性。 (3)137Cs法估算发现坡耕地的平均侵蚀模数最大。定量遥感法估算的流域的平均侵蚀模数为5494.62t/km2.a，属于强度侵蚀区域。 (4)根据对研究区水土流失特征的研究以及土壤侵蚀量的计算，提出针对研究区水土流失治理的5种模式，并对5种模式中的3种措施的水土保持效益进行评价，其结果表明植物篱措施在提高土壤的抗侵蚀能力和改善土壤的肥力方面，具有最好的效果，其次是坡改梯措施，最后是草地围栏措施。 |
| 英文摘要 | Jinsha River, one of the largest hydropower base constructing in China, has the biggest sand transporting capacity in the upper Yangtze River. When the Jinsha River flows into the Changdu region of the eastern Tibet, it belongs to Hengduan mountainous region where is the alpine-gorge area with large elevation difference, deep river cutting and severe soil and water loss. Aixigou watershed is the first grade tributary of Jinsha River in the upper reaches. Because of the severe soil and water loss, the Aixgou watershed has low land productivity, serious grassland degradation, and the ecological environment of Aixgou watershed deteriorated with natural disasters occurred frequently like drought, flood and waterlogging, debris flow. Based on the relationships between land use and soil erosion, and the datum acquired from the methods and techniques of landscape pattern analysis, RS、GIS、137Cs, the soil erosion characteristics in the study area were analyzed, the empirical model of soil erosion estimation in the typical watershed of the Hengduan mountainous region in the eastern Tibet were constructed along with verification and application. The study results were as follows. (1) Water erosion was the major erosion types in the study watershed. Water erosion mainly happened on the low coverage grassland and slope farmland by sheet erosion. The elevation determined the erosion types. The erosion intensity had close relationships with the spatial structure of land use and the grade of slope. The coniferous forest and low coverage grassland were the dominant landscape in the study area. The fragmentation degrees of open forest land, bush forest and low coverage grassland were the highest which might aggravate the soil erosion. The edge effects of river system and moderate coverage grassland were the biggest that they were the erosion juncture area of water erosion and other erosion types. The landscape heterogeneity indices of farmland transformed from grassland and moderate coverage grassland were the highest, all of which were very intensive erosion area，and this landscape structure was harmful to the soil and water conservation in the study watershed. （2）The evaluation models of soil erosion factors in the study area were initially built up based on the RUSLE model. It found that the exponential function was the most suitable one to the R factor, K factor calculated by the method from RUSLE was the best choice, LS factor should be calculated under the classification of the slope degree, C factor could be calculated by the vegetation coverage, and P factor had little influence in the study area only by the terraced field fixed the value of 0.03. The average erosion modulus calculated by the model was 4391.72t/km2.a. It was verified that the erosion intensity distribution estimated was similar as the field investigation, the model estimated erosion intensity classification was more well-distributed than the results of quantitative remote sensing method, the average erosion modulus of slope farmland and grassland estimated by the model had the same value range as the results of 137Cs method. Therefore the erosion model built for the typical watershed of the Hengduan mountainous region in the eastern Tibet was dependable. (3) It was found by the estimation method of 137Cs that the slope farmland was the main sediment yield source and the grassland was the most complicated one about the erosion condition. It was estimated by the quantitatively remote sensing method that the average erosion modulus of the whole watershed was 5494.62t/km2.a which belonged to intensive erosion area. (4) The soil conservation benefits of 3 control measures of the 5 patterns were studied. It found that the hedgerows were the most effective measure both on improving the soil anti-erosion ability and soil fertility. The measure of transforming slope farmland into terrace came the next and grassland fence was the last effective one. |
| 学科主题 | 水土保持学 |
| 语种 | 中文 |
| 公开日期 | 2010-10-13 |
| 分类号 | P61;S15 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/2161]  |
| 专题 | 成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前） |
| 推荐引用方式 GB/T 7714 | 辜世贤. 藏东横断山区典型小流域水土流失量预测模型研究[D]. 成都. 中国科学院水利部成都山地灾害与环境研究所. 2009. |
入库方式： OAI收割
来源：成都山地灾害与环境研究所
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