基于SRTM DEM的大中流域地表水文模拟研究

【作者】 余杰；

【导师】 左小清；

【作者基本信息】 昆明理工大学 ， 地图学与地理信息系统， 2009， 硕士

【摘要】 随着数字技术的飞速发展,“3S”技术、数字高程模型(DEM)、Internet技术等为流域管理研究提供海量的流域信息,而在地形图数字化、空间数据的管理、空间分析、数字地形模型构建等方面,GIS则为数字流域研究提供了功能强大的开发和应用平台,水文与3S技术的结合是我国水文模型研究的必然发展趋势。目前基于空间分析技术的水文模拟研究大多是在数字高程模型DEM的基础上进行,DEM是用于流域地形分析研究的主要数据,基于GIS和DEM的流域地表水文模拟可为分布式水文模型提供下垫面数据输入。本论文在ArcGIS平台上,利用Arc Hydro Tools,以红河流域和滇池流域为例,在SRTM DEM基础上,基于D8算法,以最陡坡度原则确定栅格单元的水流流向,以集水面积阈值确定河道起始点及河道,从子流域出口沿河道向上游搜索每一河道的上游给水区,得到了整个流域及各个子流域的边界,从而生成数字红河流域和数字滇池流域,完成了滇池流域和红河流域的地表模拟,最后对河网模拟结果和流域提取精度进行对比分析。本论文主要研究工作如下：(1)将地理信息系统应用于水文模型,介绍利用DEM提取流域特征的方法,分别构建红河和滇池的数字流域,结果显示流域河网与数字水系图的河网基本相符,提取的流域面积与水文部门的相关数据基本相符,可以作为分布式水文模型的参数,表明利用DEM提取流域水文信息在充分提高工作效率的同时可以保证信息提取的精度,论证了基于Arc Hydro Tools提取流域信息,不论从效率还是精度来看都是可行的,而且其图形化界面具有形象直观的优点。(2)将数字水系信息融入DEM,增加数字河网的提取精度,一定程度上解决了丘陵地区和平原地区提取的数字河网与实际河网差别较大的问题,提高了洼地和平原区数字河网提取精度；(3)对滇池流域和红河流域两个具有不同范围、不同形态的流域进行了提取实验,验证SRTM DEM数据在中大区域的地表水文模拟方面的优势；(4)利用Arc Hydro Tools工具中的point delineation提取流域内任意一点的子流域,为下一步综合流域地质、水文、气候、土壤、植被等信息建立流域水文模型打下良好的基础；(5)介绍一种新的有效的数据源CGIAR-CSI SRTM DEM数据,为部分地区数据获取困难的问题提供一种新的尝试。更多还原

【Abstract】 With the rapid development of digital technology, "3S" technology, digital elevation models (DEM) and Internet technology provide mass information for watershed management. While in the topographic maps digitalization, spatial data management, spatial analysis, digital terrain model building, etc., GIS has provided a powerful development and application platform for digital watershed study. Combination of hydrological and 3S technology is an inevitable trend of development for hydrological model study. Currently data used in hydrological simulation studying, which base on spatial analysis, mostly from digital elevation model. The basin surface hydrological simulation based on GIS and DEM can provide underlying data input for distributed hydrological model.This paper analyzes red river and the Dianchi Lake Basin. Analysis tool is Arc Hydro Tools from ArcGIS. Based on the SRTM DEM, based on the D8 algorithm, we determine grid cell’s flow of water flows by the principle of the most steep-degree principle, and river channel and its starting point by catchment area threshold. Also we determine the entire basin and the sub-basin boundaries from the export of sub-basins along the river channel to river upstream search Water District, thereby generating digital Red River and digital Dianchi Lake basin, getting surface model of Dianchi Lake and the Red River basin. Then we analyze river network and watershed extraction accuracy of simulation results.Main research content is as follows:(1) Combining GIS and hydrological models, introducing the watershed feature extraction methods based on DEM, and construct the Red River and Dianchi Lake basin, results showed that river basin network consist with digital River’s network of waterways map.Extraction of drainage area and hydrological services in the basic line with relevant data,it can serve as a distributed hydrological model parameters. The same time it can guarantee the accuracy of information extraction. It is also demonstrated that extracting watershed information based on the Arc Hydro Tools, regardless of efficiency or the accuracy are feasible and intuitive.(2) Fitting digital stream into the DEM can increase extraction accuracy of river network, a certain extent, solve the problem that.difference between digital and actual river network in hilly and plain areas. It also increased extraction accuracy of river network in depressions and river plain area;(3) Through watershed extraction experiments of the Dianchi Lake and the Red River basin, which has different scales and forms, shows the advantages of SRTM DEM data used in the large area of surface hydrological modeling.(4) The use of’delineation extract’ command in Arc Hydro Tools, we can extract sub-basins at any point. It greatly facilitates the extraction of the sub-basins, thereby lay a good foundation for next work that integrated watershed geology, hydrology, climate, soil, vegetation and other information to establish hydrological model.(5) Introduces a new and effective data source CGIAR-CSI SRTM DEM data, solved the data acquisition problems in some areas.更多还原