Ten-year evapotranspiration estimates in a Bornean tropical rainforest
Ten-year evapotranspiration estimates in a Bornean tropical rainforest
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DOI：
10.1016/j.agrformet.2011.04.005
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发表时间：
2011-09-15
影响因子：
6.2
通讯作者：
Kumagai, Tomo'omi
中科院分区：
文献类型：
--
作者：
Kume, Tomonori;Tanaka, Nobuaki;Kumagai, Tomo'omi
这项研究是为了量化马来西亚沙捞越热带雨林总蒸发量的年际变化。为此，我们进行了10年的气象观测，并建立了一个简化的大叶模型，将蒸腾作用(ET)、降雨截留(EI)和ET作为这些因素的总和。利用涡动协方差通量、基于穿透雨和树干径流的降雨截留以及两年多的树干液流测量对模型进行了独立验证。使用该模型估计了2000-2009年期间的ET、EI和ET。年平均ET值为1114 mm，EI值为209 mm，ET值为1323 mm，具有较小的季节波动。与年降雨量相当大的年际变化(CV=11%)形成鲜明对比的是，导出的估计值显示出保守的ET、EI和ET的年际变化(CV=5-7%)。该站点特殊的降雨特征(如强而持续时间短的风暴)可以解释保守的EI年际变化。研究期间气象条件的小年际变化和没有严重干旱可以解释ET的年变化小的原因。为了描述我们现场的ET，我们还将我们现场的EI和ET与其他热带森林的EI和ET进行了比较。基于得到的ET值特征，我们讨论了该站点ET值随降水形势变化的可能变化。(C)2011爱思唯尔B.V.保留所有权利。
This study was undertaken to quantify interannual variations of total evaporation (ET) in a tropical rainforest in Sarawak, Malaysia. To this end, we conducted 10-year meteorological measurements and formulated a simplified big-leaf model that reproduces transpiration (Et), rainfall interception (Ei), and ET as the sum of these. The model was validated independently using eddy covariance fluxes, rainfall interception based on throughfall and stemflow measurements, and sap flow measurements conducted for more than 2 years. Using the model, Et, Ei, and ET were estimated for the period 2000-2009. Annual Et, Ei, and ET averaged over 10 years were estimated as 1114, 209, and 1323 mm, respectively, with small seasonal fluctuations. The derived estimates showed conservative year-to-year variations in annual Et, Ei, and ET (CV = 5-7%) in contrast to considerable year-to-year variations in annual rainfall (CV = 11%). Specific rainfall characteristics (e.g. intense short duration storms) at this site can explain the conservative year-to-year Ei variations. Small interannual variations in meteorological conditions and absence of severe drought during the study period can explain the small year-to-year Et variations. To characterize ET at our site, we also compared Ei and ET at our site with those of other tropical forests. Based on the derived ET characteristics, we discuss possible ET changes in response to changes in rainfall regime at this site. (C) 2011 Elsevier B.V. All rights reserved.