基于DEM的福建省小流域划分研究

以1∶10万的数字线划图为工作底图,在ARC/INFO软件环境下,采用空间内插法生成福建省的DEM。其在ARC/INFO软件的水文模块环境下,经过数据预处理、流向分析、汇流分析和流域识别等过程,最终自动提取1435个小流域。研究结果表明:在山区,流域界线基本与分水岭吻合,但在平坦地区由于等高线稀疏,加上福建海岸线非常曲折,海湾支离破碎,流域提取的结果不尽人意,流域界线需要人工进一步修正。基于DEM的流域的快速提取,大大节省了的人力、物力,从提取的效率和精度来看都是切实可行的。随着DEM的精度将不断提高,这种方法将为在全省范围内实现流域各自然要素空间组合特征的快速分析与站点观测数据的综合管理,以及流域信息的空间可视化浏览、查询、统计和流域水文模型的应用分析奠定了坚实的基础,从而推动了生态环境保护、生态环境建设等生态环境管理工作的实施。

A Study on the Classification of Watersheds in Fujian Province Based on DEM

Based on Digital Line Graphic(contour,scale:1/100 000) ,firstly,the authors produce DEM(Digital Elevation Model,30×30m ) of Fujian Province by GIS special interpolation technology under the environment of ARC/INFO software.Secondly,under the environment of hydrologic model of ARC/INFO software,through DEM pretreatment,flow direction analysis,flow accumulation analysis and watershed recognization,1 435 small watersheds are extracted.The result of the study shows:In the mountain area,the watershed boundary line is almost identical to the ridge line,but in the flat country,the result is less satisfactory because of DEM precision,devious coastline and bitty bay,the watershed boundary line needs revising artificially further.The fast extraction of the watersheds based on DEM saves manpower and material resources greatly,which is feasible according to efficiency and precision.With constant improvement of the precision of DEM,this method will lay solid foundation for the quick analysis of spatial combination characteristics of various physical geographic elements within the range of watersheds in the whole province,data management of observation stations synthetically,and the visual browse,inquiry,statistics and hydrology of model analysis,which will promote the implementation of eco-environment managements,such as eco-environmental protection,eco-environment con-struction,etc.