植被冠层通过对降水的拦截可以改变降水的数量及空间分布、调节地表径流，进而影响生态系统的水分循环。冠层截留过程极易受到多种因素的影响，且不同植被的冠层截留具有差异性。在全球气候变化的背景下，降水变异性的增加、植被的物候效应及土地利用的变化深刻影响着水循环的各个环节，也会进一步对植被冠层截留造成影响。对于植被冠层截留测定方法有人工模拟法和间接观测法,冠层截留模型的研究往往以间接观测结果作为基础。当前我国研究的冠层截留模型主要分为3类：经验模型基于实测资料可揭示不同影响因素与冠层截留的关系；理论模型侧重于冠层截流内在机制，但对于研究者的数学计算能力要求较高；半经验半理论模型参数较少且具有相对明确的物理意义，因此在研究中得到广泛应用。未来我国冠层截留研究可重点关注草本植被冠层截留及变化、结合全球尺度的遥感数据进行方法改进以及冠层截留模型与全球环境变化模型耦合等方面。

The quantity and spatial distribution of precipitation are changed by the interception of vegetation canopy,and then affect the water cycle of ecosystem.Evaluated canopy interception and its temporal and spatial dynamic changes accurately is of great significance for exploring the process of eco-hydrological cycle and revealing the impact of climate change. Abundant literature analysis is used to deepen the understanding of the interception mechanism.Precipitation characteristics,vegetation physiological characteristics,and meteorological factors affect the canopy interception process.With the continuous precipitation,the canopy interception rate first increased and then decreased.The continuous expansion of vegetation leaf area is conducive to precipitation interception.Wind speed,air temperature,canopy dryness,and other factors can increase additional interception.Precipitation is intercepted variously among different vegetation types.The canopy interception rate of trees is about 30% and that of crops is only about 15%.Precipitation variability is increasing,and the phenological effect of vegetation and land use are also changing,which will deeply affect all links of the water cycle,and then affect the interception of the vegetation canopy.Artificial simulation and indirect observation are used to determine the interception water volume.The artificial simulation method is used to determine the interception water of a few low herbs,shrubs,and crops,and the measurement results are often greater than the actual direct observation.The estimation of interception through the water balance equation is called the indirect observation method,which can well obtain the dynamic change of precipitation interception.The canopy interception model combined with the results of indirect observation can simulate a wider range of canopy interception water.Three canopy interception models have been studied in China.Canopy interception mechanism is one of the emphases of theoretical models,and it requires higher mathematical computing power for researchers.The semi-empirical semi-theoretical model is widely applied because of its fewer parameters and relatively clear physical meaning. Based on the above contents,the research on canopy interception is discussed and prospected:(1) Herbaceous plants play an important role in ecological maintenance and green city construction in arid and plateau areas,so they should be paid more attention;Different canopy interception measurement methods and problems existing in the operation process will lead to great uncertainty in the measured results,and the measurement method can be improved in combination with global scale remote sensing data;The canopy interception model can be coupled with the global environmental change model to enhance the applicability of the model.