基于Arc Hydro Tools的广西小流域划分研究

Arc Hydro Tools-based small watershed division in Guangxi

为实现广西地区小流域的科学管理,加快水土保持信息化建设,以25 m分辨率DEM为基础,根据广西地形地貌特点,结合行政区划、水系分布等,对广西地区进行了小流域划分研究。为此,采用Arc Hydro Tools水文数据模型建立小流域自动划分模型进行初步划分,并针对平原区、海岸带等自动划分效果不理想的区域,利用人工处理方式对该区域进行修正。经过拓扑检查、属性编码和质量控制后,最终完成对全广西共计9 631条小流域边界的提取。结果表明:所提取小流域面积大多集中在10~50 km^2之间,无小于3 km^2和大于100 km^2的小流域,符合标准规范;自动化处理模型可对小流域进行快速划分,处理面积达到82.88%;有针对性的人工处理可提高划分精度,使得结果更为理想。研究成果对小流域信息化建设、水文模拟具有重要参考价值。

In order to realize the scientific management of small watersheds and speed up the informationization construction for water and soil conservation in Guangxi Zhuang Autonomous Region, a study on the small watershed division in Guangxi is made on the basis of the DEM with the resolution of 25 m in combination with the administrative division, water system distribution, etc. according to the topographic feature therein. Therefore, a model for the automatic division of small watershed is established with an Arc Hydro Tools-based hydrological data model for the preliminary division, and then modifications are made with the manual processing mode for those regions, i.e. plain area, coastal zone, etc. , for which the effect of the automatic division is not so desirable. After topological checking, attribute encoding and quality control, the boundary extraction of total 9631 small watersheds in Guangxi is finally finished. The result shows that the areas of the extracted small watersheds are mostly concentrat- ed between 10 - 50 km^2 without those small watersheds of less than 3 km2 and larger than 100 km2, and then conform to the rele- vant standard and specification. The automatic processing model can make a rapid division of small watershed with the processing area up to 82. 88%, while the targeted manual processing can enhance the division precision and make the result more prefera-ble. This study result has an important reference value for both the informationization construction and the hydrological simulation of small watershed.