区域水土流失评价的遥感与核素示踪技术研究
文献类型：学位论文
| 作者 | 许宜北 |
| 学位类别 | 博士 |
| 答辩日期 | 2007 |
| 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 | 贺秀斌 |
| 关键词 | 水土流失评价 核素示踪 遥感 锦屏 |
| 学位专业 | 自然地理学 |
| 中文摘要 | 土壤侵蚀是人类社会所面临的最重要的环境问题之一，水土流失现状调查和定量评价是预防水土流失、掌握水土流失动态的一项重要手段，从而为制定水土保持规划、布设水土保持措施和水土保持与生态建设宏观决策提供准确的信息和科学的依据。本论文将遥感技术与核示踪技术二者有机结合，利用遥感解译获取区域水土流失因子信息，以 137Cs侵蚀示踪技术获取不同土地利用地块的土壤侵蚀量，基于GIS数据分析处理技术，实现区域水土流失的定量评价，为区域水土流失快速评价提供一条高效途径。取得了如下成果：（1）水土流失遥感调查具有宏观、快速、效率高的优点，可以实现水土流失时空动态监测，但是实际应用中存在缺乏成熟的评价估算模型和经验或观测数据，限制了水土流失评价的精度、准确性和应用范围。我国水土流失遥感调查是利用遥感获取水土流失因子信息，与土壤侵蚀分级指标表对照判断不同土地利用单元的水土流失强度，形成区域水土流失现状或强度图。本研究利用137Cs核素侵蚀示踪技术估算不同土地利用单元的土壤侵蚀量，突破了遥感水土流失调查依赖模型和观测数据的瓶颈。实现了水土流失评价的宏观与微观、点与面、估算与实测的结合。（2）137Cs核素示踪法能够简便、快捷地提供准确的水土流失背景值，与其它方法相比，不仅具有无时空限制、操作简便快捷的优点，而且可提供上世纪60年代以来的多空间尺度（测点到流域）年均净侵蚀量，特别是水土流失监测资料和相应的水文观测资料较缺乏的地区，核素示踪法显示出较大的优越性。本研究对锦屏水电站工程区典型土地利用地块进行了137Cs核素侵蚀示踪研究：区内坡度为18度林地，侵蚀模数为765 t•km-2•a-1； 22度灌木林地，侵蚀模数为1060t•km-2•a-1；28度草地，侵蚀模数为799 t•km-2•a-1；14度坡耕地，侵蚀模数为3463 t•km-2•a-1； 25度坡耕地，侵蚀模数为5466 t•km-2•a-1；水平梯田137Cs含量超出测量精度。(3)利用遥感与核素示踪联合评价技术对总面积为10 612.9 km2的锦屏二级水电站区域的水土流失现状进行了评价：土壤侵蚀面积为5 849.2 km2，占区域土地总面积的55.1%。按照侵蚀类型划分，水力侵蚀面积达3180 km2，占土壤侵蚀总面积的54.4%。冻融侵蚀面积达2 669.2 km2，占水土流失总面积的45.6%。在水力侵蚀中，轻度水力侵蚀面积1 480.6 km2，占水力侵蚀总面积的46.6%；中度水力侵蚀面积1 236.5 km2，占水力侵蚀总面积的38.9%；强度水力侵蚀面积363.1 km2，占水力侵蚀总面积的11.4%；极强度水力侵蚀面积78.6 km2，占水力侵蚀总面积的2.5%；剧烈水力侵蚀面积21.2 km2，占水力侵蚀总面积的0.7%。 |
| 英文摘要 | Soil erosion is one of the most important environmental problems confronted with human beings. The quantitative evaluation and on-site investigation of soil erosion are the important means of preventing and controlling soil erosion, which will help establish water and soil conservation planning and provide reasonable basis for water and soil conservation construction and decisions-making. With the aid of GIS, the paper integrates the remote sensing with radionuclide tracing to quantative evaluation of regional soil erosion. The soil erosion information of the total area is obtained from remote sensing and the soil erosion amount of different fields is calculated by the 137Cs tracing technology. The method provides an effective tool for rapid and correct evaluation of regional soil erosion. The main study contents and conclusions of this study are put up as follows: The remote sensing technology can fastly and accurately perform the soil erosion dynamical monitoring. Radionuclide tracing not only independently offer some information of soil erosion deposition and space distribution, but also provide average annual net erosion amount from moniting sites to small watersheds since the sixties of last century. Compared with other methods, radionuclide tracing technique has the advantages of no space-time limiting and simple operation. The remote sensing combined with the radionuclide tracing, can realize soil erosion evaluation on the microcosmic and macrocosmic scales, and will extremely raise the accuracyand space-time resolution. Radionuclide tracing technique can fast and correctly provide background values for soil erosion. The method is better, especially to the areas with the absent observation data. Therefore, to some extent, it is effective supplement to remoting sense observation. The Jinping secondary hydraulic power station with the area of 10612.9 km2 is chosed as a study area. Based on GIS, the remote sensing combined with the 137Cs tracing technique was applied to valuate soil erosion in the area. By the remote sensing technique, to the study area, the soil erosion area has come to 5849.2 km2, accounting for 55.1% of the total study area. Water erosion area and freezing erison area are up to 54.4% and 45.6% of the total erosion area. As the national erosion intensity classes standard, slight, middle, intense, extreme and vilolent erosion area comes to 46.4%, 38.9%, 11.4%, 2.5% and 0.7%, respectively, of the total water erosion area.By using the 137Cs tracing technique, under the current land use condition, the average soil erosion rates of the grass-wood slopes, the cultivated slopes in the study area are 1125-2 535, 2 954-5 446 t•km-2•a-1. The study shows that the 137Cs tracing technique provides accurate soil loss background values, which supplys precious experience for wide application of the relative construction projects. |
| 学科主题 | 水土保持学 ; 摄影测量与遥感技术 |
| 语种 | 中文 |
| 公开日期 | 2010-10-21 |
| 分类号 | S15;S1 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/2275]  |
| 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 | 许宜北. 区域水土流失评价的遥感与核素示踪技术研究[D]. 成都. 中国科学院水利部成都山地灾害与环境研究所. 2007. |
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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