Calculating highly fluctuated suspended sediment fluxes from mountainous rivers in Taiwan
Calculating highly fluctuated suspended sediment fluxes from mountainous rivers in Taiwan
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DOI：
10.3319/tao.2005.16.3.653(t
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发表时间：
2005-08
影响因子：
0.8
通讯作者：
S. Kao;Tsung-Yu Lee;J. Milliman
中科院分区：
文献类型：
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作者：
S. Kao;Tsung-Yu Lee;J. Milliman
小流域、高度破碎的岩石、地势起伏大以及坡度陡，使得台湾的流域对台风和地震等偶发性事件以及各种人为干扰特别敏感。在此，我们分析了来自台湾的一个长期水文数据集的特征，并重新评估了用于计算台湾受事件驱动的河流的含沙量的方法。我们建议使用分层到季节水平的水位流量关系曲线法，以反映流量与悬移质含沙量之间关系的快速变化。开发了一个程序来确定构建水位流量关系曲线的最佳时间间隔，并用于计算每小时、每日、每年以及长期平均悬移质含沙量。应用于每小时流量的季节性水位流量关系曲线对于计算应对偶发性事件（特别是台风）的含沙量和含沙浓度尤为关键。计算得出的浊水溪和北港溪的累积长期平均含沙量远小于使用月加权平均（MWA）法计算得出的结果（达德森等人，2003年）。由于在高流量事件期间更频繁地观测含沙量，MWA法可能高估了平均含沙量。
Small drainage basins, highly fractured rock, high relief, and steep gradients make Taiwan watersheds particularly sensitive to episodic events such as typhoons and earthquakes, and to various types of anthropogenic disturbance. Here we analyze the characteristics of a long-term hydrological dataset from Taiwan and re-evaluate methods used to calculate sediment loads for Taiwan's event-driven rivers. We suggest using the rating curve method stratified clown to seasonal levels to reflect the rapid changes in the relationship between water discharge and suspended sediment load. A program is developed to determine the optimal time-interval for constructing rating curves, and is used to calculate hourly, daily, yearly, and long-term mean suspended sediment loads. Seasonal rating curves applied to hourly discharges are particularly critical to calculate sediment fluxes and concentrations in response to episodic events, particularly typhoons. The calculated cumulative long-term mean sediment fluxes for the Jhou-Shuei and Bei-Nan Rivers are considerably smaller than those calculated using monthly weighted average (MWA) method (Dadson et al. 2003). The MWA method likely over-estimates the mean load clue to more frequent sediment observations during high-flow events.