Precipitation‐snowmelt timing and snowmelt augmentation of large peak flow events, western Cascades, Oregon
Precipitation‐snowmelt timing and snowmelt augmentation of large peak flow events, western Cascades, Oregon
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俄勒冈州喀斯喀特西部大峰流量事件的降水-融雪时间和融雪增强
DOI：
10.1002/2014wr016877
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发表时间：
2014
影响因子：
5.4
通讯作者：
Julia A. Jones
中科院分区：
文献类型：
--
作者：
K. Jennings;Julia A. Jones
这项研究测试了多种水文学机制来解释极端雨雪洪水中的积雪动力学，这种洪水广泛发生在温带和极地地区。我们研究了俄勒冈州西部H.J.安德鲁斯实验森林1992-2012年期间26-10天的大风暴事件，使用了每小时融雪蒸渗仪、空气和露点温度、风速、降水和流量数据的统计分析(回归、方差分析和小波相干)。所有事件都涉及积雪外流，但只有7个事件连续出现净积雪外流，包括排名最高的5个峰值排放事件中的3个。峰值流量与降水量无关，但与10日降水量之和和积雪净流出有关，表明积雪对持续融化的洪水响应增强。研究中最大的两个峰值流量事件在多个时间尺度上具有显著的小波相关性，在12-32h的时间尺度上，降水和净积雪流出之间的位相差分布在π/2弧度处有一个尖锐的峰值，蒸渗仪之间的积雪流出具有很强的相关性，占流域面积的42%。极端雨雪事件的秘诀包括积雪内持续缓慢的融化，这似乎在整个景观中的积雪内产生了一个接近饱和的区域，因此积雪可能会将降水的压力波直接传递到溪流中，这一过程在整个景观中是同步的。需要进一步的工作来了解整个积雪地区积雪融化的内部动力学及其对极端雨雪洪水的贡献。
This study tested multiple hydrologic mechanisms to explain snowpack dynamics in extreme rain‐on‐snow floods, which occur widely in the temperate and polar regions. We examined 26, 10 day large storm events over the period 1992–2012 in the H.J. Andrews Experimental Forest in western Oregon, using statistical analyses (regression, ANOVA, and wavelet coherence) of hourly snowmelt lysimeter, air and dewpoint temperature, wind speed, precipitation, and discharge data. All events involved snowpack outflow, but only seven events had continuous net snowpack outflow, including three of the five top‐ranked peak discharge events. Peak discharge was not related to precipitation rate, but it was related to the 10 day sum of precipitation and net snowpack outflow, indicating an increased flood response to continuously melting snowpacks. The two largest peak discharge events in the study had significant wavelet coherence at multiple time scales over several days; a distribution of phase differences between precipitation and net snowpack outflow at the 12–32 h time scale with a sharp peak at π/2 radians; and strongly correlated snowpack outflow among lysimeters representing 42% of basin area. The recipe for an extreme rain‐on‐snow event includes persistent, slow melt within the snowpack, which appears to produce a near‐saturated zone within the snowpack throughout the landscape, such that the snowpack may transmit pressure waves of precipitation directly to streams, and this process is synchronized across the landscape. Further work is needed to understand the internal dynamics of a melting snowpack throughout a snow‐covered landscape and its contribution to extreme rain‐on‐snow floods.
中纬度山区环境中雨雪和晴天融雪期间观测到的能量通量的变化
影响因子：
3.8
作者：
Garvelmann J;Pohl S;Weiler M
通讯作者：
Weiler M