典型表层岩溶泉域植被对降雨的再分配研究

本文在表层岩溶泉域植被结构特征分析的基础上，监测桂林丫吉试验场S31号泉域内香椿和云实两种主要植被的穿透雨和树干径流特征以及钻孔和表层岩溶水的变化。结果表明:香椿林的总穿透雨量1 861.83 mm，占总降雨总量的59.65%；云实灌丛总的穿透雨量为1 626.42 mm，占总降雨量的52.11%；穿透雨率随降雨量增加而减少。香椿林的树干径流总量为89.4 mm，占总降雨量的2.86%；云实灌丛的树干径流总量为27.79 mm，占总降雨量的0.89%；香椿林和云实灌丛的林冠截留总量分别为1 169.97 mm和1 466.99 mm，平均截留率为37.48%和47.01%；用水量平衡法计算得出以灌丛覆盖为主的S31号表层岩溶泉域年蒸散量为1 623.81 mm,占降水量的52.03 %,年径流深度为1 497.39 mm，占降水量的47.97%。植被冠层改变了降雨对表层岩溶带的补给形式和补给量。降雨经过植被冠层的截留后转化成穿透雨和树干径流进入表层岩溶带，穿透雨以连续波状的形式补给表层岩溶带，而树干径流则以快速集中的方式补给表层岩溶带。 

Redistribution of precipitation by vegetation and its ecohydrological effects in a typical epikarst spring catchment

Study of precipitation redistribution by vegetation and its effects on epi-karst water in southwest of China could guide the ecological protection and comprehensive development and utilization of karst water resources. Based on the analysis of the characteristics of two typical plants, this paper presents a study on this issue in a typical epikarst spring catchment, Southwest China. The results show that the through rainfall in Toona sinensis (S1) vegetation is 1,861.83 mm, accounting for 59.65% of the total precipitation. Through rainfall in Caesalpinia decapetala (S2) vegetation is 1,626.42 mm, accounting for 52.11% of the total precipitation. The through rainfall rate decreases with increasing precipitation. Stem flow in S1 is 89.4 mm, accounted for 2.86% of total precipitation. Stem flow in S2 was 27.79 mm, accounted for 0.89% of total precipitation. Interception storage in S1 and S2 are 1,169.97 mm and 1,466.99 mm, accounting for 37.48% and 47.01% of total rainfall, respectively. Using the water balance method, annual evapotransipiration in the Yaji typical epikarst spring catchment is 1,623.81 mm, accounting for 52.03% of the precipitation, and runoff depth is 1,497.39 mm, accounting for 47.97% of the precipitation. Canopy could change the precipitation recharge pattern and quantity to epi-karst zone. Precipitation is intercepted by canopy and partitioned into through rainfall and stem flow, while through rainfall supplements the epi-karst zone in a continuous wave-like manner. The vegetation interception can reduce the total supply of rainfall to the epi-karst zone, but increases the effective supply. Compared with Caesalpinia decapetala, Toona sinensis vegetation would increase the effective recharge to epikarst zone.