中文摘要：

在众多植被截留模型中，针对场次降雨建立的概念性指数模型由于具有一定的物理基础，且参数通过常规观测资料即可确定，在构建物理性流域水文模型时被广泛采用。但在水文模型的应用中，计算是逐时段进行的，这造成模型计算时段和适用时段之间的不匹配，是植被截留计算误差的原因之一。分析表明，无论在一个计算时段内有多个降雨过程发生，还是一场降雨过程被划分为多个计算时段，逐时段计算均将过高估计植被截留量。

英文摘要：

Canopy interception plays an important role in rainfall-runoff simulation for highly-vegetated area. A great deal of models for interception is presented, of which the conceptual exponential model proposed by Merriam is heavily used in physically based hydrological models for its simplicity and physically reasonability. The exponential model is valid for a single rainfall event, while the hydrological models always run by a certain time interval. The incompatible between time scale of the model and scale of its application leads to simulation error of canopy interception, which is analyzed in the paper. The results show that either the single rainfall event is partitioned into several simulation time intervals in the hydrological models, or several independent rainfall events occur during one simulation time interval, the canopy interception is always over-estimated.