Abstract
This study presents the work commenced in northern Thailand on spatial and temporal variability of rainfall. Thirty years (1988-2017) rainfall data of eight meteorological stations were used for assessing temporal variability and trend analysis. The results showed decreasing trend in rainfall from its first half of the observed study period (1988-2002) to last half of the time period (2003-2017) in total average annual as well as monsoonal average rainfall by 14.92% and 15.50% respectively. It was predicted from linear regression results that by 2030 the average annual and monsoonal rainfall will drop by 35% and 34.10% respectively. All stations showed negative trend except Fakara met-station in annual rainfall. In the seasonal trend analysis, the results showed decreasing trend almost in all met-stations. Mann-Kendall trend test was applied to assess the trend. All met-stations show significant negative trend. To assess drought in the study area, Standardized Precipitation Index (SPI) was applied to 12-month temporal time period. The results predicted meteorological drought in the near future. The spatial distribution of rainfall presented changing phenomena in average annual, monsoonal, winter, and summer seasons in both analyzed periods.
Highlights
The aim of this paper is to examine the variations in rainfall in terms of trend, variability, spatial and temporal distribution and drought using standardized precipitation index (SPI) in Uttaradit province
During the past 30 years (1988-2017) annual rainfall data were collected for Uttaradit province which shows decreasing trend
It was observed that average annual rainfall during the period of 1988-2002 was higher than the second period (2003-2017) by 14.92%
Summary
The southwest monsoon commences in May and ends in October which brings warm humid air from Indian Ocean to Thailand and is the main cause of intense rainfall in the study area but this rainy season is influenced by inter tropical convergence zone and tropical cyclone. The second monsoon season starts from mid October and culminates in mid of February This brings cold and dry air from China to northern and northeastern parts of Thailand [1]. The main objective of this study is to observe the trend of rainfall and drought conditions in Uttaradit Province, Thailand. The aim of this paper is to examine the variations in rainfall in terms of trend, variability, spatial and temporal distribution and drought using standardized precipitation index (SPI) in Uttaradit province. To achieve the research objective, we proposed several methods such as Mann-Kendall trend test, Sen’s slope estimation test and Standardized Precipitation Index (SPI)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
