密云山区林冠层对天然降雨能量影响的初步研究

Changes of Nature Rainfall Energy Through Forest Canopy in Miyun Mountain Region

通过定点长期激光雨滴谱(LNM)观测,对北京密云山区油松林内外降雨动力学特征进行了对比研究。结果表明,林外天然雨滴平均直径和雨滴中数直径都有随降雨强度的增加而增加的趋势;林外的雨滴直径较林内分布范围小,林外雨滴直径与累积雨量之间的关系曲线较林内平滑;小雨强(≤0.55 mm/h)气候条件下,林内降雨动能显著高于林外降雨动能,可初步认为在小雨强时林冠层对降雨能量有增大作用。

Using advanced laser LNM raindrop spectrum detector, we detected the precipitation in Beijing Miyun mountains area; Combining previous methods and results of studies on Raindrop, analysis the change of raindrop features and the rainfall energy from forest outside to inside. The study indicated thaf the average diameter and D^50 of natural raindrops of outside rain were decreased along with enhanced rainfall intensity; the rainfall diameter distribution outside forest canopy was commonly lower than that of inside; the outside curve between raindrops diameter and cumulative precipitation is smoothing than inside; In the conditions with low rainfall intensity（≤0. 55 mm/h）, the inside rainfall energy significantly higher than that of outside. So it could be agreed with that forest canopy had increased the role of rainfall energy when low rain intensity.