Title

Calculating Highly Fluctuated Suspended Sediment Fluxes from Mountainous Rivers in Taiwan

Translated Titles

計算台灣高山河流之高變異沉積物輸出通量

Authors

高樹基(Shuh-Ji Kao);李宗祐(Tsung-Yu Lee);John D. Milliman

Key Words

Suspended sediment flux estimate ; Rating curve ; Taiwan

PublicationName

Terrestrial, Atmospheric and Oceanic Sciences

Volume or Term/Year and Month of Publication

16卷3期(2005 / 08 / 01)

Page #

653 - 675

Content Language

英文

English Abstract

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.

Topic Category 基礎與應用科學 > 地球科學與地質學