Water Footprint Assessment for Irrigated Paddy Cultivation in Walawe Irrigation Scheme, Sri Lanka

Water footprint (WF) is a comprehensive summation of the volume freshwater consumed directly and indirectly in all steps production chain product. The water concept has been widely used agricultural resources management. for irrigation supplied Sri Lanka to farmers at no cost, thus question arising, whether current management strategies authorities follow are appropriate achieve productive utilization. Therefore, this study aims evaluating rice an scheme dry zone Lanka, Walawe scheme. Due unreliability rainfall area paddy cultivation depends entirely on irrigation, thus, WFblue, other terms evaporated from supply considered as total WF (WFtot) study. Actual crop evapotranspiration (equivalent ETblue) was estimated based Penman-Monteith (P-M) model integrating effective rainfall, coefficient published Lankan Irrigation Design Guidelines. spanned three years 2018–2021. issued field data recorded by government body responsible area—Mahaweli Authority Lanka. percolated computed employing balance method while assuming runoff negligible. Results show that average annual WFblue found be 2.27 m3/kg, which higher than global national WFtot. As yield (6.5 ton/ha) also (4.49 (3.5 yields, conclusion drawn usage (CWUTblue) may significantly higher. It then noted CWUTblue due relatively area. Thus, it vital reduce excess shifting practices flooded System Rice Intensification (SRI).