Intensity, Duration and Spatial Coverage of Aridity during Meteorological Drought Years over Northeast Thailand

Abstract

Gaps in drought monitoring result in insufficient preparation measures for vulnerable areas. This paper employed the standardized precipitation index (SPI) to identify meteorological drought years and the Thornthwaite aridity index (TAI) to evaluate aridity in three provinces of northeast Thailand growing cassava and sugarcane at massive scales. Precipitation and temperature data were sourced from Global Land Data Assimilation System-2 (GLDAS-2) Noah Model products at 0.25 degree resolution and used for calculating the drought indices. This study was conducted for the period of 2004 to 2015. The SPI was computed for 1, 3 and 6 months scales to measure short- to medium-term moisture. The results indicated major meteorological drought years as 2004, 2005, 2010, 2012, 2014 and 2015. A range of 1 to 3 months of extreme rainfall shortage was experienced during each of these years, including the growing season of 2004, 2012 and 2015. TAI-based results indicated that the area experiences an average of 7 to 8 months of aridity during drought periods, compared to the historical overall average of 6 months. The spatial TAI for the major drought years indicated delayed onset, intermittency or early cut-off of the rainy season. The year 2004 was the most intense in terms of aridity. The longest duration of aridness for some areas was between 9 and 10 months in 2012 and 2014, respectively. In terms of spatial coverage, all meteorological drought years had out-of-season aridity. Based on the region’s historical records, this highlighted an increase in the frequency of droughts and duration of aridity. A disturbance in the growing season has the potential to affect crop yields, hence, the need to improve and strengthen existing adaptive measures for agriculture as the main source of food and income in the northeast.

Accepted Guidelines on the Potential of Water Budgets for Solving Droughts: A Case Study of Chum Saeng Sub-District, Satuek District, Buri Ram Province, Thailand

“…That is, water could not be used for meeting the water demands after the rainy season, as shown in Figures 18-20. These conditions depict a drought situation as faced in the lowest rainfall year according to historic records for the northeast region of Thailand [39] The reservation volume in the case of the lowest rainfall after the rainy season (November) was lower than the lowest reservation volume. That is, water could not be used for meeting the water demands after the rainy season, as shown in Figures 18-20.…”

“…That is, water could not be used for meeting the water demands after the rainy season, as shown in Figures 18-20. These conditions depict a drought situation as faced in the lowest rainfall year according to historic records for the northeast region of Thailand [39]…”

The Effect of Climate Variability on Cultivated Crops’ Yield and Farm Income in Chiang Mai Province, Thailand

“…Additionally, research has suggested that longan trees may be vulnerable to drought during critical stages such as flowering and early fruit development [69]. Thailand faced a devastating drought from November 2009 to August 2010, with temperatures exceeding 40 • C; in addition, between 2015 and 2016, one of the worst droughts in decades caused critically low water levels in reservoirs, mainly affecting central and northeastern areas [70].…”