Groundwater harvesting to help reuse irrigation water for increasing both food and environmental security in arid environment

The identification and application of innovative technologies and management practices that promote reuse of irrigation water offer opportunities to increase both food and environmental security in arid environment. To support agriculture in a water scarce region, water harvesting is usually promoted as rainwater harvesting and floodwater harvesting. However, in several arid regions around the world like Syria, Jordan, Yuman, Egypt, Australia, and Balochistan in Pakistan and Iran; historical evidence indicates another technique, which relates to groundwater harvesting by using system like qanat (karez), artesian well and dug well. This paper presents another type of groundwater harvesting system, called as a subsurface collector well, which operates under gravity mode to recover fresh groundwater from an aquifer underlain by saline groundwater layers. This modelling study investigates the hydro-salinity behaviour of a groundwater harvesting system at the catchment level in Australia. The results outline the usefulness of such systems under arid environment in reusing irrigation water for crop production to ensure food security, as well as managing root zone salinity for better soil environment to guarantee environmental security. The outcomes of this study have a potential to address similar issues (salinization) and/or needs (water harvesting) exist elsewhere in the world, particularly in arid regions.