Dew formation and its long-term trend in a desert riparian forest ecosystem on the eastern edge of the Taklimakan Desert in China
Dew formation and its long-term trend in a desert riparian forest ecosystem on the eastern edge of the Taklimakan Desert in China
复制标题
塔克拉玛干沙漠东缘荒漠河岸森林生态系统露水形成及其长期趋势
DOI：
10.1016/j.jhydrol.2012.09.015
复制
发表时间：
2012-11-23
影响因子：
6.4
通讯作者：
Chen, Zhong-sheng
中科院分区：
文献类型：
--
作者：
Hao, Xing-ming;Li, Cong;Chen, Zhong-sheng
降露水可以成为维持沙漠生态系统水平衡的重要水资源，例如中国塔克拉玛干沙漠的极度干旱地区。然而，人们对该地区露水的形成、数量特征以及影响因素知之甚少。这项研究利用观测数据阐明了该地区的露水形成及其长期趋势，这些数据包括使用涡流协方差系统获得的通量、气象和土壤含水量数据以及该地区气象站记录的数据。结果如下： (1)胡杨林内形成露水，夜间降露持续时间约为2 h。观测期间（2011年6月4日—10月24日）日均降露水量为0.12毫米。降露日数为104天（占总降露天数的73%），累计降露量为12.87毫米。 （2）冠层和土壤表面的降露水日数和露水量分别为86天和8.64毫米，38天和4.23毫米。表层土壤比凝露能吸收更多的水蒸气。 (3)不同时间尺度(半小时、日、半年)降露持续时间、降露量及气象因素存在明显变化。 （4）近51年来，夏季（6月10月）降露日数变化与同期总降露水量变化趋势相似。夏半年平均露水量17.2毫米，约占夏半年降水量的64%，约占全年降水量的50%。特别是，过去51年中有五分之一的降露水总量高于年降雨量。研究证明，露水是塔克拉玛干沙漠干旱地区重要的水资源之一，对水平衡也有显着影响。 (C) 2012 Elsevier B.V. 保留所有权利。
Dewfall can be a substantial water resource crucial for maintaining water balance in desert ecosystems such as the hyper-arid zone of the Taklimakan Desert in China. However, little is known about the formation, quantitative characteristics, and factors influencing dewfall in this region. This study elucidates dew formation and its long-term trend in this region using observational data, including flux, meteorological, and soil water content data obtained using the Eddy covariance system and those recorded by a weather station in the area. The results are as follows: (1) Dew forms in the Populus forest, with nighttime dewfall duration being about 2 h. The average daily dewfall amount during the observation period (June 4 October 24, 2011) was 0.12 mm. The number of dewfall days was 104 days (73% of total days), and the cumulative dewfall amount was 12.87 mm. (2) The dewfall days and amounts on the canopy and soil surfaces were 86 days and 8.64 mm, and 38 days and 4.23 mm, respectively. The top soil can absorb more water vapor than condensed dew. (3) At different time scales (half-hour, day, and half-year), obvious variations in dewfall duration, dewfall amounts, and meteorological factors occurred. (4) Over the past 51 years, changes in the number of dewfall days during the summer (June October) exhibited a trend similar to that of changes in total dewfall amount during the same period. The average dewfall amount during the summer half-year was 17.2 mm, which is about 64% of the summer half-year rainfall and 50% of the annual rainfall. In particular, the total dewfall amount was higher than the annual rainfall amount during the one-fifth of the past 51 years. The study proved dewfall is one of important water resources in the arid Taklimakan Desert region, and it also significantly influenced the water balance. (C) 2012 Elsevier B.V. All rights reserved.