摘要
利用南流江流域30 m分辨率的DEM数据,介绍了Arc GIS中进行河网提取的一系列过程,并利用其图解建模工具,提取南流江流域的不同汇流累积面积的水系河网,实现了提取过程的流程化处理。分别统计河源密度和沟壑密度,并分别计算它们与汇流累积面积的几何函数关系,并对其进行二阶求导,确定其二阶导数关系,得到合适的汇流累积阈值,并借助分形分维理论对河网的分维值进行了验证。利用函数关系和分形分维确定汇流累积面积提取水系河网的方法有效地避免了人工选择汇流累积面积的主观性,提高了研究结果的准确性和可靠性,在知道研究流域河网分维值的前提下,可快速获取准确的汇流累计面积阈值。
Using Nanliu river basin 30 m resolution of DEM data,this paper introduces the Arc GIS for river network in extraction of a series of process,and use its graphical modeling tool,and extract the Nan Liu river basins of different river confluence area of water system,realizes the extraction process routing process. Statistical heyuan density and gully density respectively,and calculate their geometric function relation with the accumulated flow area,and carries on the second order derivative calculation,determine its second derivative relationship,to get the right bus accumulation threshold,and with the help of fractal dimension fractal theory calculating fractal dimension value of the river network is verified. Function relation and the fractal dimension is used to determine the flow accumulation methods of extracting drainage river network area is effective to avoid the subjectivity of the convergence of artificial selection accumulation area and improve the veracity and reliability of the results of the study,under the premise that know river fractal dimension is worth study basin,can quickly get accurate confluence area threshold.
出处
《测绘与空间地理信息》
2016年第3期114-118,共5页
Geomatics & Spatial Information Technology
关键词
DEM
河网
集水面积阈值
南流江
分形分维
DEM
river network
catchment area threshold
Nanliu river
fractal dimension
