Assessing the Irrigability Index of Selected Irrigation Systems in Camarines Sur, Philippines

Concerns about irrigation performance associated with water dependability and climate change threats to food security stress the need to evaluate water adequacy and understand climate impacts on irrigated environments. The study assessed the irrigability index of selected irrigation systems in Camarines Sur, Philippines. Geodatabases were processed in QGIS to determine the slope and soil-based potential irrigable areas and calibrated SWAT models simulated streamflow for water resources-based potential irrigable areas. Results revealed insufficient water in irrigation systems to support continuous flooding of service areas, especially during the dry season, highlighting vulnerability to water supply fluctuations. Climate change is projected to exacerbate water insufficiency issues. Low irrigability indices also limit further irrigation development despite high land suitability. The study recommends improving geodatabases, optimizing cropping calendars, and using water-saving technologies. The study's methodology and results can aid in irrigability index assessments and may serve as a reference in planning and managing irrigation projects.