| Summary: | 碩士 === 國立中興大學 === 水土保持學系 === 93 === This study estimated sediment yield in upstream watershed of Nan-Ao-Bei Creek and a tributary of Lainyang River. Using DEM（Digital Elevation Model）, SPOT images and GIS（Geographic Information Systems) technology to predict sediment transport mechanisms.
In this study, the USLE (Universal Soil Loss Equation ) was used to estimate soil loss from slope lands. The method suggested by Khazai and Sitar was employed to predict the landslide quantity. Combining SDR (Sediment Delivery Ratio ), channel attenuation rate and precipitation, the watershed sediment yields can be estimated in a storm event. In the meantime, simulate hydrograph derived from GRAPH（Grid Rational Algorithm for Predicting Hydrograph）. Then discuss relationship of the simulation results and sediment yields.
The results indicated that in upstream watershed of Nan-Ao-Bei Creek the sediment yield from slope land is 147,045.25 m3 per year, and average erosion depth is 0.4 cm per year. The landslide quantity is 2,317,090 m3 and average denudation depth is 1.55 m. The sediment yield（SY） equation about accumulate precipitation before peak discharge（r） for the upstream watershed of Nan-Ao-Bei Creek is SY＝66.593r+4838.7，R2＝0.9563*** .In the other watershed, the sediment yield from slope land is 13,746.71 m3 per year, and average erosion depth is 0.13 cm per year. The landslide quantity is 502,560 m3 and average denudation depth is 1.55 m. The sediment yield equation is SY＝6.4941r+649.57，R2＝0.9286**.
|
|---|
