Geomorphic effects of the extreme rainfall event of 20–21 july, 2004 in the latnjavagge catchment, northern swedish lapland
Geomorphic effects of the extreme rainfall event of 20–21 july, 2004 in the latnjavagge catchment, northern swedish lapland
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2004年7月20日至21日瑞典拉普兰北部latnjavagge流域极端降雨事件的地貌影响
DOI：
10.1111/j.0435-3676.2005.00267.x
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
Olga Sandberg
中科院分区：
文献类型：
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作者：
A. Beylich;Olga Sandberg
对2004年7月20-21日瑞典拉普兰地区阿比斯科山区Latnjavagge流域(9 km2,950-1440 ma.s.l；68°20‘N，18°30’E)发生的24 h内降雨量为58.4 mm，48 h内降雨量为71.7 mm的罕见降雨事件引发的质量传输进行了量化和分析，并与该流域的年平均质量传输进行了直接对比分析。在没有罕见降雨的年份，Latnjavagge流域的特点是沉积物供应有限，导致机械剥蚀和质量转移较低。在2004年7月20日至21日这一罕见降雨事件期间，通过了Latnjavagge集水区斜坡系统(引发泥石流和滑坡)和渠道系统(渠道泥石流路面和台阶池系统的破裂)的主要稳定性阈值，泥石流、滑坡以及小溪和河道中河流泥石流的质量转移比Latnjavagge流域的年均质量转移高出数倍。在计算较长期的质量转移和泥沙收支时，必须将2004年7月20-21日降雨这样的罕见事件视为基本组成部分。对这种罕见事件的复发间隔进行可靠的估计尤其有问题。指出了确定适当长度的过程监测方案的一般问题。
Abstract Mass transfers triggered by a rare rainfall event on 20–21 July, 2004, with 58.4 mm of rain within 24 h and 71.7 mm of rain within 48 h in the Latnjavagge catchment (9 km2 , 950–1440 m a.s.l.; 68°20'N, 18°30'E) in the higher Abisko mountain region (Swedish Lapland), are quantified and analysed in direct comparison with mean annual mass transfers in this drainage basin. In years without rare rainfall events the Latnjavagge catchment is characterized by restricted sediment availability resulting in low mechanical denudation and mass transfers. During the rare rainfall event of 20–21 July, 2004, major stability thresholds on the slope systems (triggering debris flows and slides) and in the channel systems (break‐up of channel debris pavements and step–pool systems) in the Latnjavagge catchment were passed and mass transfers by debris flows, slides and fluvial debris transport in creeks and channels were several times higher than the mean annual mass transfers in Latnjavagge. In the calculation of longer‐term mass transfers and sediment budgets, rare events like the 20–21 July, 2004 rainfall event have to be considered as essential components. A reliable estimation of the recurrence intervals of such rare events is especially problematic. The general problem of defining an adequate length of process monitoring programmes is pointed out.