河网提取算法中河道断裂现象原因剖析及算法改进  

The reason analysis of the phenomenon of “disconnection” in the DEM river extraction and method improving

作　　者：刘佳嘉[1] 周祖昊[1] 贾仰文[1] 王浩[1] 

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038

出　　处：《中国水利水电科学研究院学报》2013年第3期195-200,共6页Journal of China Institute of Water Resources and Hydropower Research

基　　金：国家自然科学基金重点项目(50939006);国家自然科学基金项目(51179203);国家自然科学基金创新群体项目(51021006);国家科技支撑计划课题(2010BAC69B02)

摘　　要：Burn-in算法和AGREE算法是目前应用广泛的基于实际河网高程强迫修正的河网提取算法。该算法能有效提取出同真实河网高拟合度的模拟河网,但某些情况下,所提取的河网会产生"断裂"现象。河网"断裂"现象的产生在于实际河网栅格高程"高估"和"低估"所引起的局部流向计算错误,其中所有"低估"类以及大部分"高估"类影响都是可以通过填洼等方法加以消除的,即不会产生"断裂"问题。真正产生"断裂"的原因是:存在"高估"类河网栅格且"高估"所带来的影响无法通过填洼等操作加以消除。基于此,对Burn-in算法和AGREE算法进行修正,提出一种消除"高估"类影响的解决方案,从根本上解决河网"断裂"问题,实现程序自动化处理。渭河流域实例应用表明,改进算法可有效解决模拟河网"断裂"问题,且适用于多种基于高程的强迫修正算法。The AGREE and burn-in algorithms are far-flung methods for the river extraction from DEM based on the modification of the actual river information, from which the extracted simulated river networks are closer to the actual ones. But in some situations, the extracted river networks may be disconnected. The reason for the drainage network disconnection is the wrong flow direction calculation from the ＂overesti- mation＂ and ＂underestimation＂, and most of them could be eliminated, i.e., the drainage network discon- nection could not happened. The sufficient condition of the drainage network disconnection is that there must be ＂overstimation＂ in the river grids and its influence could not be eliminated by drainage network ex- traction processes. Thus, an improved method is promoted. First, the elevation of the river grids within the DEMs are modified to make sure that the upper river grids are greater than the lower river grids, i.e., eliminating the effect of the ＂overestimation＂. Second, the Burn-in or AGREE method is used to extract the river networks. The application to the Weihe River Basin reveals that the improved method could solve the problem of river ＂disconnection＂ efficiently, and could be used for the elevation modification.

关 键 词：Burn-in算法 AGREE算法 河网提取 河网修正 改进 

分 类 号：P333.9[天文地球—水文科学]