Critical points: interctions between on-farm irrigation systems and water distribution network. Application in Bembezar M.D., Spain

Abstract

In this work, a new model useful to analyze interactions between the on-farm irrigation system supplied by critical points and the water supply network management is developed. The model evaluates the impacts of changes in the pressure head and demand simultaneity on the irrigation systems and evaluates the emitters’ discharge and uniformity. Also, the potential reductions in yield due to lower uniformity are evaluated. The methodology is applied in Bembézar Irrigation District (Southern Spain). Results showed that the additional cost required for giving maximum pressure in the critical point does not offset the increase in yield. Hence, an increment from 91.7 % to 92.1 % in yield in the critical field would represent increases in energy consumption from 0.15 kWh m-3 to 0.17 kWh m-3. Also, the unit energy cost could be reduced in up to 0.11 kWh m-3 not implying significant reductions in yield. The importance of a good election of emitters in the critical fields is also evaluated.