Assessment of climate change impacts on drought severity using SPI and SDI over the Lower Nam Phong River Basin, Thailand

Main Article Content

Tanawut Pandhumas
Kittiwet Kuntiyawichai
Chatchai Jothityangkoon
Fransiscus Xaverius Suryadi


The Lower Nam Phong River Basin, which is located in Northeast Thailand, is impacted by drought, which is likely to increase in severity in the future. Since drought seriously affects human life and well-being, this assessment was focused on the impacts of climate change on drought severity in the Lower Nam Phong River Basin. Daily climate data, such as rainfall and temperatures, for 2020 to 2050 under emission scenario Representative Concentration Pathway (RCP8.5), were obtained from “HadGEM2-AO”, downscaled by the Regional Climate Model version 4 (RegCM4), and bias-corrected via the Delta Change Method. Drought conditions were then classified based on the Standardized Precipitation Index (SPI) calculated from future daily rainfall, and the Streamflow Drought Index (SDI) derived from future daily discharge at each sub-basin outlet obtained from the Soil and Water Assessment Tool (SWAT) model simulations. At the E.22B gauging station, the SWAT performance was found to be satisfactory for all evaluation criteria, i.e. R2 and NSE values were 0.86 and 0.74 for calibration (2005 – 2010), and 0.92 and 0.89 for validation (2011 – 2016), respectively. For drought risk assessment, the point-based SPI and SDI values at 3- and 6-month time scales were spatially interpolated using kriging to assess short-term drought conditions. Based on the SPI-6 during the mid-future period (2041 – 2050), the Lower Nam Phong River Basin would have the highest chance of drought with cumulative frequency of 90.7%, whereas based on SDI-6 the highest chance of drought would occur during the near-future period (2031 – 2040) with cumulative frequency of 97.5%. These findings imply that both SPI and SDI indices can be used as good alternatives for monitoring droughts in the Lower Nam Phong River Basin; however, validation is required to ensure forecast accuracy of droughts in the near- to mid-future time horizons.


Download data is not yet available.

Article Details

How to Cite
Pandhumas, T., Kuntiyawichai, K., Jothityangkoon, C., & Suryadi, F. X. (2020). Assessment of climate change impacts on drought severity using SPI and SDI over the Lower Nam Phong River Basin, Thailand. Engineering and Applied Science Research, 47(3), 326-338. Retrieved from


[1] Intergovernmental Panel on Climate Change. The physical science basis: contribution of working group I to the fifth assessment report of the Intergovernmental Panel on Climate Change (IPCC). Cambridge, United Kingdom: Cambridge University Press; 2013.

[2] Thailand Science Research and Innovation. Thailand’s second assessment report on climate change. Bangkok, Thailand: Thailand Science Research and Innovation; 2016.

[3] U.S. Agency for International Development (USAID). A review of downscaling methods for climate change projections: African and Latin American Resilience to Climate Change (ARCC). Washington: USAID; 2014.

[4] Wongsasri S. Water quantity and quality assessment for Lower Phong Basin by SWAT Model [Dissertation]. Khon Kaen, Thailand: Khon Kaen University; 2012.

[5] Thai Meteorological Department. Drought [Internet]. 2017 [cited 2018 Jun 5]. Available from:

[6] Secretariat Office of the Chi River Basin Committee. Management of the Chi River Basin. Khon Kaen, Thailand: Water Resources Regional Office 4, Department of Water Resources, Ministry of Natural Resources and Environment; 2012.

[7] Kuntiyawichai K, Sri-Amporn W, Pruthong C. Quantifying consequences of land use and rainfall changes on maximum flood peak in the Lower Nam Phong River Basin. Adv Mater Res. 2014;(931-932):791-6.

[8] Hydro Informatic Institute. Data collection and analysis of 25 basin in Thailand (Chi River Basin) and flood-drought simulation. Bangkok, Thailand: Hydro Informatic Institute; 2012.

[9] Pholpuech, S. Basic information on drought. Bangkok, Thailand: The Secretariat of the House of Representatives Printing Office; 2005.

[10] Disaster Prevention and Mitigation Provincial Office (Khon Kaen, Thailand). Strategy for Disaster risk management of Khon Kaen. Khon Kaen, Thailand: Disaster Prevention and Mitigation Provincial Office; 2019.

[11] McKee TB, Doesken NJ, Kleist J. The relationship of drought frequency and duration times scales. 8th Conference on Applied Climatology; 1993 Jan 17-22; Anaheim, California. USA: American Meteorological Society; 1993. p. 179-84.

[12] Aghelpour P, Bahrami-Pichaghchi H, Kisi O. Comparison of three different bio-inspired algorithms to improve ability of neuro fuzzy approach in prediction of agricultural drought, based on three different indexes. Comput Electron Agr. 2020;170:1-12.

[13] Nalbantis I, Tsakiris G. Assessment of a hydrological drought revisited. Water Resour Manag. 2009;23:881-97.

[14] Reanalyses. Reanalysis. [Internet]. 2010 [cited 2020 Mar 6]. Available from:

[15] Oh SG, Park JH, Lee SH, Suh MS. Assessment of the RegCM4 over East Asia and future precipitation change adapted to the RCP scenarios. J Geophys Res Atmos. 2014;119:2913-27.

[16] National Institute of Meteorological Sciences. Participating models [Internet]. 2018 [cited 2019 May 6]. Available from:

[17] Peters GP, Andrew RM, Boden T, Canadell JG, Ciais P, Quéré CL, et al. The challenge to keep global warming below 2 degrees C. Nat Clim Change. 2013;3:4-6.

[18] Leng G, Hall J. Crop yield sensitivity of global major agricultural countries to droughts and the projected changes in the future. Sci Total Environ. 2019;654:811-21.

[19] Rathjens H, Bieger K, Srinivasan R, Chaubey I, Arnold JG. CMhyd user manual: documentation for preparing simulated climate change data for hydrologic impact studies. Texas: SWAT; 2016.

[20] Minville M, Brissette F, Leconte R. Uncertainty of the impact of climate change on the hydrology of a Nordic Watershed. J Hydrol. 2008;358:70-83.

[21] Hongsawong P, Samsalee R, Sittichok K. The study of parameter sensitivity of SWAT Model for runoff simulation in Maeklong River Basin [Internet]. Thailand: Department of Irrigation Engineering, Kamphaensaen Kasetsart University; 2016 [cited 2018 Jun 9]. Available from:

[22] Abbaspour KC, Ashraf VS, Srinivasan R. A guideline for successful calibration and uncertainty analysis for soil and water assessment: a review of papers from the 2016 international SWAT Conference. Water. 2018;6:1-18.

[23] Yuttaphan A, Baimuang S. Bias correction technique for meteorological data of climate model output under the scenario focus on regional economic development (A2). Naresuan Univ Eng J. 2014;8:34-9.

[24] National Drought Mitigation Center-UNL. SPI Generator free software, version release date 6 September 2018 [Internet]. 2018 [cited 2019 Apr 18]. Available from:

[25] Dalezios NR, Tarquis AM, Eslamian S. Drought. In: Dalezios NR. Droughts. Dalezios NR, editor. Environmental hazards methodologies for risk assessment and management. London, UK: International Water Association Publishing; 2017. p. 177-210.

[26] Hong X, Guo S, Zhou Y, Xiong L. Uncertainties in assessing hydrological drought using streamflow drought Index for the upper Yangtze River Basin. Stoch Environ Res Risk Assess. 2014;29:1235-47.

[27] Khaewsuriyan A. Statistical downscaling model for evaluating climate change impacts on rainfall in Chi and Mun River Basin [Dissertation]. Pathumthani, Thailand: Thammasat University; 2008.

[28] Chomtha T. A study of meteorological drought index model for drought areas in Northeastern Thailand. Bangkok, Thailand: Meteorological Department; 2006.

[29] Moriasi DN, Arnold JG, Van Liew MW, Bingner RL, Harmel RD, Veith TL. Model evaluation guidelines for systematic quantification of accuracy in watershed simulations. Trans ASABE. 2007;50:885-900.

[30] Krause P, Boyle DP, Base F. Comparison of different efficiency criteria for hydrological model assessment. Adv Geosci. 2005;5:89-97.

[31] Nash JE, Sutcliffe JV. River flow forecasting through conceptual models: part I. A discussion of principles. J Hydrol. 1970;10:282-90.

[32] Dau QV, Kuntiyawichai K, Suryadi FX. Drought severity assessment in the Lower Nam Phong River Basin, Thailand. Songklanakarin J Sci Tech. 2018;40:985-92.

[33] Department of Disaster Prevention and Mitigation. Analysis of drought risk area in Northeastern Thailand. Bangkok, Thailand: Department of Disaster Prevention and Mitigation; 2007.