分布式水文模型子流域编码方法对比分析

Comparison analysis of subwatershed codification methods for distributed hydrological model

根据分布式水文模型对子流域编码的要求,对文献中河流和流域编码方法进行研究。研究发现只有5种编码方式符合要求,分别是:拓扑属性表法、二叉树编码、多叉树编码、Pfafstetter法、干支拓扑编码。在深入研究这5种编码规则的基础上,对比分析其优缺点,并以第二松花江作为实例进行子流域划分及编码。结果表明:拓扑属性表法、多叉树编码和干支拓扑编码方法在河段单一汇流、多河段汇流支持方面优于其他编码方法;在直接计算相邻上下游子流域编码方面,拓扑属性表法可以直接查找获取,二叉树编码和干支拓扑码编码方法可直接计算,Pfafstetter编码和多叉树编码均需要遍历整个编码体系进行搜索获取;在判别任意2个子流域上下游关系方面,Pfafstetter编码和干支拓扑码均优于其他3种方法。不同编码方式具有各自的优缺点,在实际应用中需要根据不同分布式水文模型具体研究内容和编码要求选择适宜的编码方式。

According to the requirements of subwatershed codification for distributed hydrological models, river and watershed codification methods described in literature were studied. It is found that only five coding methods can meet the requirements of distributed hydrological models ： the topological property table coding method （TPTCM）, binary-tree coding method （BCM）, multi-tree coding method （MCM）, Pfafstetter coding method （PCM）, and stem-branch topological coding method （SBTOPO）. The advantages and the disadvantages of the five methods were examined based on analysis of their coding rules. The second Songhua River was selected as the study area for subwatershed division and codification. The results show that the TPTCM, MCM, and SBTOPO are superior to the other two methods in one-way and multi-way confluence situations. The TI^CM can directly find and obtain the codes of adjacent inflow and outflow subwatersheds, and the BCM and SBTOPO can directly calculate their codes, but the PCM and MCM obtain their codes by searching the entire coding system. The PCM and SBTOPO are better than the other three methods in terms of analysis of the upstream and downstream relationships between any two subwatersheds. All five coding methods have their own advantages and disadvantages. A suitable coding method should be selected according to research contents and coding requirements of distributed hydrological models in practical applications.