Chiang Mai Journal of Science

 Cassava starch is a crucial agro-industry in Thailand. Cassava is extensively cultivated and processed into the final products in the country to be consumed and exported. Cassava cultivation and processing have a large impact on water resources, and also creates stress on water availability. Water footprint (WF) is the tool used for measuring the total amount of water consumed by an individual or an entire nation, and can be used to provide a clear overview mapping of water use during the time in which the product is consumed or traded. The aims of this study were to calculate the average WF of cassava starch production from crop to final product consumed under the WF concept methodology, and to assess the virtual water flow (VWF) of cassava starch trade in Thailand during the period of 2008-2013. The results showed that the average WF of crop cultivation was equal to 528 m³/ton, consisting of green (187 m³/ton), blue (251 m³/ton) and grey (90 m³/ton) components. The average WF of cassava starch was equal to 1,945 m³/ton product, consisting of green (678 m³/ton), blue (925 m³/ton) and grey (342 m³/ton), respectively. The amount of water required for crop cultivation is associated with the climatic and soil conditions. Moreover, adopting good farming practices and the most efficient irrigated water scheduling can reduce the amount of water needed per ton of crop cultivation. However, the water used in crop processing depends on processing operation and technology. The VWF of global exported cassava starch from Thailand was 3.68 billion m³/year, almost 85% of which was distributed throughout Asia. The largest importers of cassava starch are China, Indonesia and Taiwan. The import of cassava starch might be able to support countries that have water scarcity problems. Instead of cultivating and processing it nationally, the import of cassava starch can help lessen the burden on domestic water resources.