Vegetative Recovery for the watershed Landslides caused by 921 Earthquake in TA-CHIA Creek
| Autor: | Chen-Chen Tsai, 蔡真珍 |
|---|---|
| Rok vydání: | 2001 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 89 Chi-Chi earthquake caused lots of landslides in Central Taiwan. Fragile debris of the landslides is susceptible to erosion and having the potential disaster during the rainy season. The effectiveness of landslide treatment should be long-term monitored. Under the limitation of manpower and finance, the priority of treatment zone needs to be set and adjusted according to the recovery status of the monitored landslides for avoiding sedimentation in the aquatic ecosystem. The river segment (Tian-Lun to Der-Ji dam) of Ta-Chia Creek was selected and the watersheds of it’s tributaries were delineated in this study. Sediment yield of the landslide, before and after the quake, in the interested watersheds were estimated by using Universal Soil Loss Equation (USLE) couple with the calculation of sediment delivery ratio (SDR). Annual erosion depth calculated from the sediment yield of watershed outlet can be as the priority index for landslide treatments. Results show that the top-three watershed need to be treated priority is No.0, No.30, and No.28 in order, and the annual erosion depth of the three watersheds is 30.04 cm, 16.59 cm, and 9.8 cm respectively. Vegetative engineering methods should be placed at the suitable sites for landslide restoration. Toe-protection work is a key to vegetative restoration for a landslide. The placement sites of toe-protection work in the analyzed watershed can be displayed effectively using the calculation of sediment delivery ratio. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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