广东省2004-2016年植被冠层降雨截留模拟及时空变化特征

评价植被冠层降雨截留能力，是生态系统水循环的重要研究内容。以广东省中小流域为例，结合地面监测站点的降雨量数据和MODIS叶面积指数遥感数据，利用植被冠层降雨截留模型，定量模拟和分析了广东省流域尺度2004-2016年的地表植被冠层降雨截留能力及其时空变化特征。结果表明：（1）2004-2012年广东省年均植被冠层降雨截留率持续下降，2016年略有上升，并且随着时间的推移，流域之间的植被冠层降雨截留率差异越来越小。（2）广东省植被冠层降雨截留能力呈现山区东西两翼高，山区中部以及沿海地区低的显著空间差异格局，这种空间格局与植被覆盖LAI主要呈现由珠三角向外围递增的圈层空间格局特征密切相关，而与由南向北逐渐递减的降雨空间格局特征相关性不大。（3）森林覆盖对流域植被冠层降雨截留能力有着一定的影响，其中流域内阔叶林占森林面积的比例对这种影响的程度起着最为关键的作用。

The simulation and spatial-temporal variations of atmospheric rainfall interception by vegetation canopies based on MODIS LAI data at the basin scale in the Guangdong Province from 2004 to 2016

Evaluating the rainfall interception capacity of vegetation canopies is an important component of water cycling in ecological systems. We employed a model of atmospheric rainfall interception by vegetation canopies with observed precipitation data from weather stations and MODIS leaf area index (LAI) data to quantitatively estimate the rainfall interception capacity of the vegetation canopy at a small-medium basin scale in the Guangdong province from 2004 to 2012 and reveal its spatial and temporal variation. The results showed that: (1) the annual mean rainfall interception rate of the canopy (RIRC) in Guangdong Province declined continuously during 2004-2012 but increased slightly in 2016. The spatial variability of RICR has diminished progressively as time goes on. (2) The RICR in Guangdong Province presented distinctive spatial patterns and was higher in the east and west mountain areas but lower in the central mountain and coastal areas. This spatial pattern was closely related to the spatial pattern of LAI, which mainly presented a ring pattern that increased from the Pearl River Delta to the periphery, but was not very related to the spatial pattern of rainfall, which showed a gradual decreasing trend from south to north. (3) The forest coverage rate had a certain impact on the canopy interception capacity, especially the areas of broad-leaved forest in the basins.