Opportunities and constraints in adapting to flood and drought conditions in the Upper Chao Phraya River basin in Thailand

ABSTRACT

To assess alterations of the rice-growing season as a sustainable option to overcome temporary groundwater storage shortages resulting from flood and drought conditions in the Upper Chao Phraya River basin in Thailand, rice was planted in May (1.5 months earlier) to harvest before seasonal flooding occurred (normally in October). The assessment showed that a cropping intensity (CI) of approximately 1.4 (100% and 40% of the total agricultural area for the wet and dry seasons, respectively) could be supported by the total available water (surface runoff and renewable groundwater storage). Shifting the growing season did not have a negative impact in terms of rice production area, but it did ensure that the area of rice cultivation avoided flooding or surface water shortage conditions. Expanding the rice production area was also assessed; however, this required the implementation of artificial groundwater recharge (AGR). For example, 1.0 km³ of AGR annually was enough to support CI equal to 1.5 without experiencing groundwater depletion.

Keywords:

• Basin management
• groundwater
• rainfed area
• rice production
• water shortage

Acknowledgements

This study was conducted under the Integrated Study Project on Hydro-Meteorological Prediction and Adaptation to Climate Change in Thailand (IMPAC-T Project). We would like to thank Mr Somkid Saphaokham, who is the director of hydrology and water resources management for the central region (Chainat province) for the RID of Thailand, for his kind cooperation with data requests between the RID and authors. We would like to express our sincere thanks to anonymous reviews and Dr Sujata Manandhar for suggestions and comments improving the paper quality.

Funding

This study was supported by the Japan Science and Technology Agency, the Japan International Cooperation Agency (JICA) [grant number 25.03061], the Science and Technology Research Partnership for Sustainable Development of Japan, and by the Monbukagakusho scholarship [grant number 123033] for the first author. The authors appreciate the generous financial support provided by these grants.