Adaptation strategies for rainfed rice water management under climate change in Songkhram River Basin, Thailand

Siriwat Boonwichai,Pragya Pradhan,Sangam Shrestha,Avishek Datta,Mukand S Babel

doi:10.2166/wcc.2021.220

Siriwat Boonwichai, Pragya Pradhan + Show 3 more

Open Access

https://doi.org/10.2166/wcc.2021.220

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Abstract

Abstract This study investigates the potential impacts of climate change on water resources and evaluates adaptation strategies on rainfed rice water management under climate change scenarios in the Songkhram River Basin, Thailand. The Soil and Water Assessment Tool (SWAT) model was used to project the future water availability under climate change scenarios for the period of 2020–2044. Future annual water availability is expected to remain unchanged due to unchanged future rainfall but expected to reduce from June to November due to changes in seasonal rainfall. The effects of supplying irrigation water to reduce the impact of climate change and increase rainfed rice production were evaluated. To increase the rice production by 15%, it is proposed to construct a reservoir with a capacity of below 65 MCM in each of the 15 sub-basins to fulfill the irrigation water requirements during the rainfed rice season. Alternatively, adaptation at the farm scale can be implemented by constructing ponds with a capacity of 900 m3 to store water for 1 ha of rice field to meet the potential rice yield during the non-rainfed rice season. The results of this study are helpful to policymakers in understanding the potential impacts of climate change and the formulation of adaptation strategies for water and rice sectors in the basin.

Highlights

Climate change has negative impacts on crop growth and production throughout the world, including many areas in Thailand
The study aims to investigate the impact of climate change on water availability and evaluate adaptation strategies for water management on rice fields at the sub-basin and farm scales for the period of 2020–2044 under RCP4.5 and RCP8.5 scenarios in the Songkhram River Basin of Thailand
Boonwichai et al ( ) projected future climate in the Songkhram River Basin, Thailand based on four regional circulation models (RCMs), namely ACCESS1.0-CSIROCCAM, CNRM-CM5-CSIRO-CCAM, ICHEC-EC-EARTH

Summary

INTRODUCTION

Climate change has negative impacts on crop growth and production throughout the world, including many areas in Thailand. Boonwichai et al ( , ) and Shrestha et al ( ) studied the potential impact of climate change on rice production in Thailand and concluded that changes in the magnitude and patterns of temperature and rainfall could alter the crop growth period, water availability, and photosynthesis process. Water resources in Thailand are affected by climate change Such impacts include projections of increased inflow into the Ubonratana Dam (Shrestha ) and reduced annual runoff in the Upper Ping River Basin (Sharma & Babel ). The study aims to investigate the impact of climate change on water availability and evaluate adaptation strategies for water management on rice fields at the sub-basin and farm scales for the period of 2020–2044 under RCP4.5 and RCP8.5 scenarios in the Songkhram River Basin of Thailand. The results of this study will provide technical and policy insights to support decision makers for the better understanding and implementation of Thailand’s water resources management strategies under the 20-year master plan (2018–2037)

METHODOLOGY

RESULTS AND DISCUSSION

CONCLUSIONS