scholarly journals A case study on the occurrence of regional debris flow hazard in central Taiwan

2008 ◽  
Author(s):  
C.-C. Lee ◽  
C.-Y. Ku ◽  
S.-M. Hsu ◽  
Y.-L. Chang ◽  
S.-Y. Chi
Keyword(s):  
Debris Flow ◽  
Central Taiwan ◽  
Debris Flow Hazard

Debris flow hazard mapping considering the effect of mitigation structure – a case study in Taiwan based on numerical simulation

2020 ◽  
Author(s):  
Chih-Hao Hsu ◽  
Chuan-Yi Huang ◽  
Ting-Chi Tsao ◽  
Hsiao-Yuan Yin ◽  
Hsiao-Yu Huang ◽  
...  
Keyword(s):  
Debris Flow ◽  
Water Conservation ◽  
Large Scale ◽  
Mass Movement ◽  
Hazard Mapping ◽  
Hazard Map ◽  
Inundation Depth ◽  
Central Taiwan ◽  
Debris Flow Hazard ◽  
Typhoon Herb

<p>This study added the dams and retain basin according to their dimensions measured with UAV onto the original 5m-resolition DEM to compare the effect of mitigation structures to debris flow hazard. The original and the modified DEMs were both applied to simulate the consequences by using RAMMS::Debris Flow (RApid Mass Movement Simulation) model.</p><p>Hazard map is the best tool to provide the information of debris flow hazard in Taiwan. It has an important role to play in evacuating the residents within the affected zone during typhoon season. For the reason, debris flow hazard maps become a useful tool for local government to execute the evacuation. As the mitigation structure is constructed, the intensity of debris flow hazard reduces.</p><p>The Nantou DF190 debris flow potential torrent is located in central Taiwan. In 1996 when Typhoon Herb stroke, 470,000 cubic-meter of debris were washed out and deposited in 91,200 square-meter area (Yu et al., 2006), and the event caused the destruction of 10 residential houses with 2 fatalities. After the event the Soil and Water Conservation Bureau constructed a 100-meter long sabo dam and sediment retain basin with capacity of 60,000 cubic-meters. In order to compare the difference of affected zone before and after the construction of mitigation structures, the study applies RAMMS to simulate the above-mentioned event.</p><p>The result shows when large-scale debris flow occurs, most of the sediments still overflow and deposit on the fan with shape similar to the 1996 Typhoon Herb event. However, the intensity has reduced significantly with 50% less in area, several meters less in inundation depth and 50% less in flow velocity approximately. The comparison shows the effect of mitigation structures and could provide valuable information for debris flow hazard mapping.</p><p>Key Words: Debris flow, RAMMS, Hazard map, Mitigation, Taiwan</p>

scholarly journals Assessment of Risk due to Debris Flow Events: A Case Study in Central Taiwan

2006 ◽  
Vol 39 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Gwo-Fong Lin ◽  
Lu-Hsien Chen ◽  
Jun-Nan Lai
Keyword(s):  
Debris Flow ◽  
Central Taiwan

scholarly journals Evaluation of Rainfall-Triggered Debris Flows under the Impact of Extreme Events: A Chenyulan Watershed Case Study, Taiwan

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2201
Author(s):  
Jinn-Chyi Chen ◽  
Wen-Shun Huang
Keyword(s):  
Debris Flow ◽  
Extreme Events ◽  
Debris Flows ◽  
Extreme Rainfall ◽  
Extreme Rainfall Event ◽  
Extreme Rainfall Events ◽  
Hourly Rainfall ◽  
Central Taiwan ◽  
The Impact

This study examined the conditions that lead to debris flows, and their association with the rainfall return period (T) and the probability of debris flow occurrence (P) in the Chenyulan watershed, central Taiwan. Several extreme events have occurred in the Chenyulan watershed in the past, including the Chi-Chi earthquake and extreme rainfall events. The T for three rainfall indexes (i.e., the maximum hourly rainfall depth (Im), the maximum 24-h rainfall amount (Rd), and RI (RI = Im× Rd)) were analyzed, and the T associated with the triggering of debris flows is presented. The P–T relationship can be determined using three indexes, Im, Rd, and RI; how it is affected and unaffected by extreme events was developed. Models for evaluating P using the three rainfall indexes were proposed and used to evaluate P between 2009 and 2020 (i.e., after the extreme rainfall event of Typhoon Morakot in 2009). The results of this study showed that the P‒T relationship, using the RI or Rd index, was reasonable for predicting the probability of debris flow occurrence.

Impacts of future climate change (2030-2059) on debris flow hazard: A case study in the Upper Minjiang River basin, China

2018 ◽  
Vol 15 (8) ◽  
pp. 1836-1850 ◽  
Author(s):  
Ming Li ◽  
Cong-shan Tian ◽  
Yu-kuan Wang ◽  
Qin Liu ◽  
Ya-feng Lu ◽  
...  
Keyword(s):  
Climate Change ◽  
Debris Flow ◽  
River Basin ◽  
Future Climate ◽  
Future Climate Change ◽  
Minjiang River ◽  
Debris Flow Hazard

scholarly journals Debris flow run off simulation and verification ‒ case study of Chen-You-Lan Watershed, Taiwan

2005 ◽  
Vol 5 (3) ◽  
pp. 439-445 ◽  
Author(s):  
M.-L. Lin ◽  
K.-L. Wang ◽  
J.-J. Huang
Keyword(s):  
Debris Flow ◽  
Deposition Process ◽  
Sensitivity Study ◽  
Affected Area ◽  
River Watershed ◽  
Run Off ◽  
Central Taiwan ◽  
Downstream Area ◽  
Typhoon Herb

Abstract. In 1996 typhoon Herb struck the central Taiwan area, causing severe debris flow in many subwatersheds of the Chen-You-Lan river watershed. More severe cases of debris flow occurred following Chi-Chi earthquake, 1999. In order to identify the potentially affected area and its severity, the ability to simulate the flow route of debris is desirable. In this research numerical simulation of debris flow deposition process had been carried out using FLO-2D adopting Chui-Sue river watershed as the study area. Sensitivity study of parameters used in the numerical model was conducted and adjustments were made empirically. The micro-geomorphic database of Chui-Sue river watershed was generated and analyzed to understand the terrain variations caused by the debris flow. Based on the micro-geomorphic analysis, the debris deposition in the Chui-Sue river watershed in the downstream area, and the position and volume of debris deposition were determined. The simulated results appeared to agree fairly well with the results of micro-geomorphic study of the area when not affected by other inflow rivers, and the trends of debris distribution in the study area appeared to be fairly consistent.

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