台灣中部地區天然闊葉林降雨截留量之探討

Study on Rainfall Interception Characteristics of Natural Hardwood Forest in Central Taiwan

陸象豫(Shiang-Yue Lu) ； 唐凱軍(Kai-Jung Tang)

《林業試驗所研究報告季刊》 10卷4期 (1995/12) Pp. 447-457

https://doi.org/10.7075/BTFRI.199512.0447

摘要

本試驗藉量測林外降雨量、穿落雨量及幹流量以推估連華池地區天然闊葉林之降雨截留量與若干截留有關之參數。由1990年6月至1991年6月試驗期間內，總降雨量計2707.70mm，穿落雨量、幹流量及樹冠截留量分別為2287.31、113.74及306.65mm。截留損失量雖僅佔全期降雨量之11.3%，然而各月份間之變異卻甚大。截留量佔降雨量之比率以冬季乾旱期爲最高，1990年12月達100%；而夏季颱風期間為最低，1991年8月僅了佔3.9%。
穿落降雨、幹流量及截留量與林外降雨之線性回歸關係式由64場降雨資料求得。但其中僅穿落雨量(P(下標 t)與林外降雨量(P(下標 g))間之相關係數較高，其關係式爲：P(下標 t)=-4.146+0.936* P(下標 k)。本試驗並以Leyton法求得該林分之樹冠截留容量爲1.879mm，穿落係數爲0.712所估測之最大截留損失量及起始截留損失量分別為5.47±0.72mm與2.27±0.87mm。此外，穿落雨之降雨中心較林外降兩之雨量中心約晚29.3±38.5min發生。

關鍵字

截留 ； 穿落雨 ； 幹流量 ； 樹冠截留容量

並列摘要

Interception loss from a natural hardwood forest in the central part of Taiwan has been determined by measuring gross rainfall, throughfall and stemflow. During the study period from June 1993 to June 1991 (records of May 1931 surer lest), the total gross rainfall was 2707.70mm and the total interception loss was 306.65mm (11.3%) with throughfall and stcmflow comprising 2207.31mm (84.47%) and 113.74mm (4.20%), respectively. However, great variations were found among the monthly percentages of interception of gross rainfall, interception was largest in the winter months, reaching 100% in November 1990, and least in the summer months especially during typhoon season, at only 3.9% in August 1990.
Linear relationships for throughfall, interception and stemflow to gross rainfall were filled using measured records from 64 rainfall events. However, only throughfall (P(subscript t) and gross rainfall (P(subscript g)) were closely related as P(subscript t)=-4.416+0.936*P(subscript g). In addition, the canopy storage capacity throughfall coefficient, canopy maximum interception capacity and rain necessary to saturate canopy were also estimated. The canopy storage city and the throughfall coefficient were estimated by the Leyton method as having values of 1.879mm and 0.712, respectively. The amount of rain necessary to saturate the canopy was estimated to be 2.27±0.87mm. The canopy maximum interception capacity was 5.47±0.72, respectively. The time lag between through-fall center and gross rainfall center for these 64 rainfall events was 28.3±38.5 minutes.

並列關鍵字

interception ； throughfall ； stemflow ； canopy storage capacity