地形指数若干计算方法探讨

Some calculation methods for topographic index

根据地形指数的物理意义,论述了3种地形指数ln(a/tanβ)的计算方法:单流向法、多流向法和改进的多流向法.在对它们进行较为深入分析的基础上,着重检验了改进的多流向法的计算效果.研究结果表明,改进的多流向法更加符合地形指数的物理意义,可以更好地反映地形对流域汇流的影响,为地形指数的计算提供更可靠的依据.

Three calculation methods for topographic index In（α/tanβ）, i.e. the single flow direction algorithm, the multiple flow direction algorithm, and the improved multiple flow direction algorithm, were discussed according to the physical meaning of topographic index, with focus placed on the effect of the improved multiple flow direction algorithm. The result shows that the improved multiple flow direction algorithm accords much better with the physical meaning of topographic index, and can reflect the impact of topography on flow concentration of river basins. The method provides a more reliable basis for topographic index calculation.