不同降雨强度下庐山日本柳杉林冠层穿透雨延滞效应  

Time lag effects of throughfall on the canopy of Cryptomeria japonica in Lushan Mountain,China under different rainfall intensity

作　　者：黄家辉 刘苑秋[1,2] 许青 李乐寰 温林生 郑希玲 刘春梅 邓文平 HUANG Jiahui;LIU Yuanqiu;XU Qing;LI Lehuan;WEN Linsheng;ZHENG Xiling;LIU Chunmei;DENG Wenping(School of Forestry,Jiangxi Agricultural University,330045,Nanchang,China;National Positioning Observation and Research Station of Lushan Forest Ecosystem,332900,Lushan,Jiangxi,China;Jiangxi Lushan National Nature Reserve Administration,332900,Lushan,Jiangxi,China)

机构地区：[1]江西农业大学林学院,南昌330045 [2]庐山森林生态系统国家定位观测研究站,江西庐山332900 [3]江西庐山国家级自然保护区管理局,江西庐山332900

出　　处：《中国水土保持科学》2023年第1期29-36,共8页Science of Soil and Water Conservation

基　　金：国家自然科学基金“庐山针叶林雾水截留、利用机制及其生态效应”(31860236);江西省林业科技创新专项“水源涵养林提质增效关键技术研究”(201808)。

摘　　要：为了探究不同降雨特征下穿透雨过程,依托庐山森林生态系统国家定位观测站,通过观测2017年雨季(4—9月)日本柳杉林内外实时降雨过程定点观测数据,并选取部分典型场次降雨(中雨、大雨和暴雨),分析不同降雨强度下柳杉林冠层时滞效应。结果表明:在2017年雨季,庐山地区降雨呈现出小降雨量(≤5 mm)、短降雨历时(≤2 h)和低降雨强度(≤2 mm/h)的特征。从林外降雨开始至林内出现降雨的起始延滞期内,起始延滞时间(y)随着林外降雨强度(x)的增大而迅速减小,两者之间呈现幂函数关系(y=0.656x^(-0.822),R^(2)=0.8234)。起始延滞时间与林外降雨量之间关系不明显。冠层滞留效应为正滞留效应时,平均降雨强度相对于冠层滞留效应为负滞留效应时更小,且在降雨初期以及降雨末期(≤2 h以及>8 h)时,滞留效应多发生正滞留效应;而在降雨达到峰值时(即降雨中期)滞留效应才会明显出现负滞留效应。在降雨过程中,林冠层对降雨的有效延滞作用主要发生在降雨起始和结束2个阶段,而在中间期冠层拦蓄作用几乎消失,出现林内降雨强度要大于林外降雨强度的情况。在进行水土流失、山洪、泥石流和滑坡等地质灾害预报时,应重点关注降雨中间期。[Background]The redistribution of precipitation by forest has always been a hot spot and difficulty in hydrology research.Japanese cedar(Cryptomoria japonica)is the main afforestation tree species in Lushan Mountain,which plays an important role in ecological function such as soil and water conservation,atmospheric purification,and forest recreation.The purpose of this article is to explore the penetration rain process under different rainfall characteristics.[Methods]We did a research on monitoring data of real-time rainfall process of C.japonica forest in Lushan Natural Protection Area from April 2017 to September 2017 based on Lushan Ecosystem Observation and Research Station.And then we selected part of typical rainfall events(three different rainfall levels),and analyzed time lag effects in different rainfall intensity.Through the 5-point method,the throughfall sample points were arranged on sample plot in forest,rainfall sample points were arranged on outside forest,and the data for both of them were collected through the auto rain gauge.[Results]In the rainy season of 2017,the rainfall characteristics of the Lushan Mountain were low(≤5 mm),low rainfall intensity(≤2 mm/h)and short duration of rainfall(≤2 h).During initial lag time from the beginning of rainfall outside the forest to the beginning of rainfall inside the forest,the initial lag time y decreased rapidly with the increase of the rainfall intensity x outside the forest,showing a power function relationship(y=0.656x^(-0.822),R^(2)=0.8234).The relationship between the initial lag time and the rainfall outside the forest was not obvious.The statistical results showed that the average rainfall intensity with positive canopy retention effect was smaller than that with the negative retention effect,and the most retention effect at≤2 h and>8 h of rainfall duration was positive,and negative retention effect was evident at>4~8 h of rainfall reaching peak(mid rainfall duration).[Conclusions]The characteristics of rainfall(rainfall intensity and dur

关 键 词：日本柳杉 降雨特征 穿透雨 庐山 

分 类 号：S715.2[农业科学—林学]