Abstract and References
Transactions on Science and Technology Vol. 6, No. 4, 340 - 351, 2019

Relationship Between Debris Flow and Precipitation From Nantou and Chiayi County in Taiwan

Chun-Yu Lin; Kuei-Hsiang Cheng

ABSTRACT
This study collected data on debris flow and precipitation from Nantou and Chiayi districts in Taiwan. According to past reports of debris flow by the Bureau of Water Conservation, there have been 19 debris flow in the Nantou area and 14 debris flow in the Chiayi area for a total of 33 reports of debris flow. Among them, 8 (42%) of the Nantou debris flow were classified potential debris flow torrents, and 11 were ordinary unclassified torrents. There were 8 events of potential debris flow torrents (57%) in the Chiayi area, and 6 ordinary unnamed torrents. According to the hydrological data from the disaster report, precipitation patterns were analyzed using effective accumulated precipitation (R), the duration of sustained precipitation, the duration of alert level precipitation, and the precipitation intensity (I) during debris flow. The precipitation patterns were analyzed using level 1 and level 2 graphs, and findings showed that there are 6 different types of precipitation patterns during debris flow. The results showed that the most significant precipitation patterns were: level 1 short-duration heavy precipitation and level 2 short-duration heavy precipitation, as short duration heavy precipitation occurred 17 times and accounted for 52%. This is in line with the current extreme climate, as short-duration torrential rain can cause disasters. The lesser-occurring mild precipitation is divided into two types: level 1 long-duration mild precipitation and level 2 short-duration long-duration mild precipitations. They occurred 2 times and accounted for 6%. A disaster prevention mechanism should be established in the future to prevent the occurrence of debris flow caused by heavy precipitation.

KEYWORDS: Debris flow; Precipitation pattern; Sustained precipitation; Mild precipitation; Heavy precipitation



Download this PDF file

REFERENCES

[1]       Central Weather Bureau (CWB). 2019. Precipitation Records 2008 to 2013 (https://www.cwb.gov.tw/eng/). Last accessed on December 2019.

[2]       Chen, H.-E. 2005. Development and Examination of Rainfall-Triggered Shallow Debris flow Model. Msc Thesis, National Chiao Tung University, Hsinchu, Taiwan.

[3]       Chen, C.-Y. 2013. Evaluation of Rainfall-Based Sediment Disaster Warning Systems: Case Studies in Taiwan and Japan (in Chinese). Journal of Soil and Water Conservation, 44(1), 50-64.

[4]       Debris Flow Disaster Prevention Information Network. 2019. https://246.swcb.gov.tw/?lang=en. Last accessed on December 2019.

[5]       Google Map. 2019. https://www.google.com.tw/maps/place/%E5%8D%97%E6%8A%95%E7%B8%A3/@23.8412218,120.7023258,110202m/data=!3m2!1e3!4b1!4m5!3m4!1s0x3468d6aa1a5d49ad:0x1348fba95f17f6da!8m2!3d23.9609981!4d120.9718638?hl=zh-TW. Last accessed on December 2019.

[6]       Lin, H.-Y. 2008. Investigation of Regional Risk Analysis for Rainfall-Triggered Shallow Debris flow. Msc Thesis, National Chiao Tung University, Hsinchu, Taiwan.

[7]       Qiu, Y.-X., Tsao, D.-Z., Chen, M.-Z. & Yang, Y.-Z. 2012. A Study on the Influence Scope of Debris flow Formed in the Kuoxizai Area of Chuko Village in Chiayi. Chinese Soil and Water Conservation Society Annual Meeting. 10-11 December, 2012. Taichung, Taiwan.

[8]       Wikipedia. 2019. Nantou County (in Chinese). (https://zh.wikipedia.org/wiki/%E5%8D%97%E6%8A%95%E7%B8%A3). Last accessed on December 2019.

[9]       Xu, S-M., Ke, J-Z., Chen, N-I. & Ji, S-Y. 2012. A Study on Debris flow Disasters in Watersheds (in Chinese). China Engineering Issue, 114, 94-98.