Village tank as an agricultural resource in the dry zone of Sri Lanka (reservoirs, efficient water use, mathematical analysis)

abastecimiento de agua alimentation en eau almacenamiento de agua asia asie bilan hydrique embalses engineering fisiologia fonction physiologique hydraulic engineering hydraulic structures mathematics measurement mesure methode methods modele modelos models ouvrage hydraulique physiological functions physiologie physiology sri lanka stockage d'eau water balance water reservoirs water storage water supply