Long-term trends and variability of total and extreme precipitation in Thailand
Atsamon Limsakul a, Patama Singhruck b
a Environmental Research and Training Center, Technopolis, Klong 5, Klong Luang, Pathumthani 12120, Thailand
b Department of Marine Science, Faculty of Science, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok 10330, Thailand
a b s t r a c t
Based on quality-controlled daily station data, long-termtrends and variability of total and extreme precipitation indices during 1955–2014 were examined for Thailand. An analysis showed that while precipitation events have been less frequent acrossmost of Thailand, they have becomemore intense.Moreover, the indices measuring the magnitude of intense precipitation events indicate a trend toward wetter conditions, with heavy precipitation contributing a greater fraction to annual totals. One consequence of this change is the increased frequency and severity of flash floods as recently evidenced in many parts of Thailand. On interannual-to-interdecadal time scales, significant relationships between variability of precipitation indices and the indices for the state of El Niño–Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO)were found. These results provide additional evidence that large-scale climate phenomena in the Pacific Ocean are remote drivers of variability in Thailand's total and extreme precipitation. Thailand tended to have greater amounts of precipitation and more extreme events during La Niña years and the PDO cool phase, and vice versa during El Niño years and the PDO warm phase. Another noteworthy finding is that in 2011 Thailand experienced extensive flooding in a year characterized by exceptionally extreme precipitation events. Our results are consistent with the regional studies for the Asia-Pacific Network. However, this study provides a more detailed picture of coherent trends at a station scale and documents changes that have occurred in the twenty-first century, both of which help to inform decisions concerning effective management strategies.
Article history:
Received 20 September 2014
Received in revised form 30 September 2015
Accepted 19 October 2015
Available online 27 October 2015
© 2015 Elsevier B.V. All rights reserved.
