Water Footprint of Local Herbs in Thailand Using the Water Footprint Network Methodology

Abstract

This study quantified the water footprint (WF) of four economically important Thai medicinal herbsCurcuma longa, Kaempferia parviflora, Andrographis paniculata and Momordica charantiausing the Water Footprint Network (WFN) methodology together with Thailand-specific climatic and cultivation data. The assessment covered green, blue, and gray WF components and incorporated basin-level water scarcity characterization. The results show that Curcuma longa had the lowest total WF (535 m³/ton), driven primarily by green water use, while Momordica charantia had the highest WF (2,152 m³/ton), reflecting substantial blue and gray water requirements. Kaempferia parviflora and Andrographis paniculata presented intermediate WFs of 1,088 and 1,869 m³/ton, respectively. Spatial analysis revealed strong provincial variability linked to rainfall patterns and irrigation demand, particularly for Momordica charantia in northern and lower-central regions. Sensitivity analysis identified crop evapotranspiration and the leaching-runoff fraction as the most influential parameters across all herbs. The findings provide a robust evidence based for optimizing irrigation practices and guiding sustainable water management strategies within Thailand’s herbal cultivation sector.