water management 228 water use 164 river basins 161 water quality 159 groundwater 141 water resources 136 irrigation management 128 irrigation water 121 case studies 91 food security 91 water allocation 88 water scarcity 88 climate change 87 farmers 87 irrigated farming 85 economic aspects 84 water supply 81 poverty 79 water reuse 73 water resource management 72 agriculture 70 water 69 water productivity 69 irrigation systems 68 water demand 67 models 63 surface water 59 crop production 58 rice 57 wastewater treatment 55