Agriculture 1 Aquifers 1 Assessment of water resources 1 Case-studies 1 Digital storage 1 Economics 1 Fresh Water 1 Groundwater depletion 1 Groundwater resources 1 Population statistics 1 Rain 1 Recharging (underground waters) 1 Remote sensing 1 Reservoirs (water) 1 Sana’a region 1 Surface water resources 1 Surface waters 1 Water crisis 1 Water demand 1 Water scarce 1 Water supply 1 Water supply and demands 1 Waters resources 1 groundwater 1 rainfall 1 surface water 1 water crisis 1