流域水文滞留时间是指水分子从降水到径流的转化时间。作为与流域内储水量、径流来源的组成比例、流经路径等直接相关的特征时间值，可以帮助我们更深层次的理解流域内水文过程的物理发生机制。近年来对水文滞留时间的研究开始增加，但是由于测量上的困难，主要都集中在少数实验小流域，并且较少关注在流域尺度。本项研究将对研究区域的山地小流域进行数字地形分析、实地采样和模型估算相结合的方法，分析找出流域内各地形特征和水文滞留时间的相关关系，以及这些主导关系随着研究尺度的变化而产生的变化。将所得到的研究结果与已有的气候地形条件有较大相似性的流域进行比较，分析异同之处以及可能的原因。同时估算出的水文滞留时间也将和数值模型模拟得到的时间相比较，从实测的滞留时间这一关于物理机制的特征时间来验证模型的结果，帮助扩展模型在不同地区的应用以及为超出经验范围的极端现象的进行解释。

Catchment scale residence time is the time that water molecule transfer from precipitation to runoff leaving the catchment. Due to the direct connection with catchment storage, sources of water, and flow pathways, it could help us reveal the underlying flow generation mechanisms at catchment scale. Although there is recent interest in residence time during recent decade, most studies are limited on hillslope processes in a handful of small catchments, few of them focused on catchment scale. By analyzing the DEM of study watershed, rainfall-runoff data, water samples collected at different seasons, combining with numerical simulation, this study aims to examine the correlation between topographic characteristics and residence time to find out the dominant factor(s), and how this change from hilllslope scale to catchment scale. The results will then be compared with the conclusions draw from catchment(s) of similar climate and topography to see the differences and potential hypotheses for this divergence or similarity. Furthermore, by comparing the estimated residence time with the one estimated individually from numerical model, it can help validate the model simulations, making sure it gets the right answers due to right reasons. The verification could give us more confidence to apply the model to basins or extreme events without a known priori.