Assessment of Landslide Hazard Areas for Chichiawan Creek Watershed in Central Taiwan

台灣中部七家灣溪集水區潛在崩塌危險地區之評定

胡蘇澄(Su-Cherng Hu) ； 李麗玲(Li-Lin Li)

《台灣林業科學》 13卷4期 (1998/12) Pp. 271-277

https://doi.org/10.7075/TJFS.199812.0271

摘要

The purpose of this study was to develop a method for the assessment of landslide hazard areas in forest watersheds, in order to determine practical guidelines for logging activites and the alignment of road networks on forest lands in Taiwan. Basic data on geology, topography, soil, land use, landslide distribution, and forest management of Chichiawan Creek watershed, upstream of the Derchi Reservoir watershed, were collected. An ARC/INFO Geographic Information System (GIS) database was populated with data on slope steepness class and slope aspect distribution, the landslide area, and the percentage area of each slope steepness class affected by landsliding. It was found that slope instability generally occurred on slopes steeper than 45%. This constituted 46.4% and 45.2% of the total landslide area in the 5th (45-100%) and 6th (＞100%) slope steepness class, respectively. When rated using the Simprecise Method, this classifies 63.24% of the watershed into high hazard and 23.46% into very high hazard landslide zones.

關鍵字

簡確法 ； 土地單元 ； 潛在崩山災害 ； 潛在崩塌危險區評定 ； 七家灣溪集水區

並列摘要

The purpose of this study was to develop a method for the assessment of landslide hazard areas in forest watersheds, in order to determine practical guidelines for logging activites and the alignment of road networks on forest lands in Taiwan. Basic data on geology, topography, soil, land use, landslide distribution, and forest management of Chichiawan Creek watershed, upstream of the Derchi Reservoir watershed, were collected. An ARC/INFO Geographic Information System (GIS) database was populated with data on slope steepness class and slope aspect distribution, the landslide area, and the percentage area of each slope steepness class affected by landsliding. It was found that slope instability generally occurred on slopes steeper than 45%. This constituted 46.4% and 45.2% of the total landslide area in the 5th (45-100%) and 6th (＞100%) slope steepness class, respectively. When rated using the Simprecise Method, this classifies 63.24% of the watershed into high hazard and 23.46% into very high hazard landslide zones.

並列關鍵字

Simprecise Method ； land unit ； landslide hazard ； landslide hazard area assessment ； Chichiawan Creek watershed