The Sediment Transportation and Denudation of Fu-shan Experimental Site

Autor: Chia-Hung Jen, 任家弘
Rok vydání: 2006
Druh dokumentu: 學位論文 ; thesis
Popis: 94
The observation of sediment transportation and denudation of two drainage basins in northeastern Taiwan during 1998 to 2000 shows that significant amounts of sediment have been evacuated from the fluvial system, although the watersheds were well vegetated and not disturbed by human activities. No landslide activity can be observed in aerial photos of this study area during 1998-2000, which implies that the sediment accumulation in the channel systems is the main source of sediment production at the drainage outlets. In this study, bedload was collected in the deposition area at the outlet of each catchment. The quantities of suspended and dissolved sediments were obtained by sampling and the construction of rating curves. The total sediment of the two catchments was 738 tons and 4372 tons, during 1998 and 2000, respectively. The average denudation in this period was 2.8 mm and 5.1 mm, and the bedload, dissolved load and suspended load were about 7%, 90% and 3%, respectively, for Catchment No. 1, and 57%, 42% and 1%, respectively, for Catchment No. 2. The results also show that bedload transportation was controlled by typhoons and heavy rainfalls. These low-frequency and high-energy events can produce large quantities of bedload, but the magnitude of the events and the bedload they transported were not linear. There are also factors that influence bedload transportation other than hydrological conditions, such as the volume and distribution of sediments and the micro relief of the channel.
Databáze: Networked Digital Library of Theses & Dissertations