Kao,S.J. and Milliman,J.D.(2008): Water and sediment discharge from small mountainous rivers, Taiwan: The roles of lithology, episodic events, and human activities. Journal of Geology, 116, 431-448.

『台湾の低山地河川からの水と堆積物の流出:地質と時たまのイベントと人間活動の役割』


Abstract
 Taiwan's natural setting creates highly vulnerable watershed whose rivers discharge disproportionately large quantities of sediments to the coastal ocean. The 16 Taiwanese rivers analyzed in this article discharge 〜180 Mt yr-1 of sediment to the coastal ocean, although totals over the past 20 years have varied between 16 and 440 Mt yr-1. The mean annual sediment yield of 9500 t km-2 yr-1 for the 16 rivers is 60-fold greater than the global yield of 150 t km-2 yr-1, but mean yields for the individual rivers vary by more than 2 orders of magnitude, from 500 to 71,000 t km-2 yr-1. Most sediment erosion and delivery occur in response to typhoon-generated floods, as evidenced by the fact that >75% of the long-term flux occurs in <1% of the time, about one-third of which reaches hyperpycnal concentrations. Detailed analysis of the 16 watersheds reveals little evidence of any single environmental factor that controls sediment load. The Erren, the highest-yield river on Taiwan, drains an erodible but low-gradient watershed with relatively low runoff. In contrast, three east coast rivers, the Hoping, the Hualien, and the Beinan, have high sediment yields that may be explained by relatively frequent earthquakes coupled with high runoff. Farming and urbanization also have elevated sediment yields in eastern watersheds, whereas Holocene sediments buried in the Taiwan Strait suggest that present-day sediment loads of the western rivers may be no higher than prehuman levels.』

Introduction
Taiwan rivers
Calculating sediment discharge
 Role of seasonal fluctuations and episodic events
 Deriving a meaningful sediment rating curve
Sediment discharge from Taiwanese rivers
Controlling factors
 Episodic events
 Hyperpycnal events
 Human activities
Concluding remarks
Acknowledgments
References cited


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