Throughfall, Stemflow and Interception Loss at Pinus taeda and Pinus densiflora stands

테다소나무림과 소나무림에서의 수관통과우량(樹冠通過雨量), 수간유하우량(樹幹流下雨量) 및 차단손실우량(遮斷損失雨量)

The objective of this study was to estimate throughfall, stemflow, interception loss and net rainfall in relation to rainfall interception, and to understand the factors affecting interception process at Pinus taeda stand and Pinus densiflora stand in the Research Forests of Seoul National University, located in Choosan, Kwangyang, Chollanamdo. 1. The gross rainfall during the period of field observation was 3,107.6mm(average 1,035.9mm/year). Most of the daily rainfall intensity was under 30mm, which was 90% in 1992, 81% in 1993 and 88% in 1994. 2. In this study the throughfall, stemflow, interception loss and net rainfall were expressed separately as a function of gross rainfall. The overall throughfall collected during the period of field observation was 2,432.5mm(78.3%) at Pinus taeda stand and 2,699.6mm at Pinus densiflora stand, out of total rainfall of 3107.6mm. The canopy storage capacity, which was determined by the prediction equation between gross rainfall and throughfall was 1.1mm at Pinus taeda stand and 1.3mm at Pinus densiflora stand. 3. The sums of stemflow from measurement of total rainfall at Pinus taeda stand and Pinus densiflora stand was 227.3mm(7.3%) and 62.7mm(2.0%), respectively. The minimum rainfall causing stemflow was estimated as 7.2mm at Pinus taeda stand and 1.9mm at Pinus densiflora stand. 4. Interception loss accounted for 447.8mm(14.4%) at Pinus taeda stand and 345.3mm(11.1%) at Pinus densiflorra stand. 5. Net rainfall was 2,659.8mm(85.6%) at Pinus taeda stand and 2,762.3mm(88.9%) at Pinus densiflora stand. 6. The rates of throughfall and stemflow increased with increasing the gross rainfall. However, the amounts of throughfall and the stemflow were constant above 30mm at Pinus taeda stand and 50mm at Pinus densiflora stand. The rates of interception loss decreased with increasing the gross rainfall. However, the amount of interception loss was constant above 50mm at Pinus taeda stand and Pinus densiflora stand.

30년생 테다소나무(Pinus taeda)림과 30년생 소나무(Pinus densiflora)림 시험구에서 수관통과우량(樹冠通過雨量), 수간유하우량(樹幹流下雨量), 차단손실우량(遮斷損失雨量) 및 임내강우량(林內降雨量)을 산정(算定)하고 이것에 관여하는 인자(因子)와의 관계(關係)를 밝힌 결과 다음과 같은 결과를 얻었다. 1. 시험기간(試驗期間)의 총강우량(總降雨量)은 3,107.6mm로, 연평균(年平均) 1,035.9mm였으며 시험기간(試驗期間)동안 조사된 일단위우량(日單位雨量)의 강우강도빈도(降雨强度頻度)는 30mm 이하가 전체의 90%(1992년), 81%(1993년), 88%(1994년)였다. 2. 선정(選定)된 총(總) 85회(回)의 단위강우(單位降雨)에 대한 수관통과우량(樹冠通過雨量), 수간유하우량(樹幹流下雨量), 차단손실우량(遮斷損失雨量)은 임외강우량(林外降雨量)과 직선관계(直線關係)를 보였다. 수관통과우량(樹冠通過雨量)은 테다소나무림에서 2,432.5mm(78.3%), 소나무림은 2,699.6mm(86.9%)였으며, 회귀식(回歸式)에 대한 단위 강우당 차단저류능(遮斷貯留能)은 각각 1.1mm와 1.3mm로 추정(推定)되었다. 3. 수관유하우량(樹幹流下雨量)은 테다소나무림에서 227.3mm(7.3%), 소나무림에서 62.7mm(2.0%)로 나타났으며, 회귀식(回歸式)을 이용하여 추정(推定)된 단위 강우당 수간유하우량(樹幹流下雨量)의 발생강우량(發生降雨量)은 각각 약 7.2mm와 1.9mm로 추정(推定)되었다. 4. 차단손실우량(遮斷損失雨量)은 임외강우량(林外降雨量)에서 수관통과우량(樹冠通過雨量)과 수간유하우량(樹幹流下雨量)을 제(除)하여 산정(算定)하였으며, 테다소나무림에서 447.8mm(14.4%), 소나무림에서 345.3mm(11.1%)로 산정(算定)되었다. 5. 수관통과우량(樹冠通過雨量)과 수간유하우량(樹幹流下雨量)의 합(合)으로 나타나는 임내강우량(林內降雨量)은 태다소나무림에서 2,659.8mm(85.6%)였고, 소나무림에서 2,762.3mm(88.9%)였다. 6. 수관통과(樹冠通過) 및 수간유하율(樹幹流下率)은 강우량(降雨量)이 증가(增加)할수록 급증(急增)하다가 각각 30mm, 50mm 이상의 강우(降雨)에서 일정(一定)하게 유지되었고, 차단손실율(遮斷損失率)은 강우량(降雨量)이 증가(增加)함에 따라 급감(急減)하다가 50mm 이상의 강우(降雨)에서 일정(一定)하게 유지되었다.