This book mainly deals with climate and hydrology (surface and sub-surface) of the Arab Region.The book contains twelve chapters and three appendices. These chapters comprise an historical introduction, physiographic features and geological settings of the region, climate, analysis of precipitation, evaporation and evapotranspiration, river basins and flow, wadi basins and flow, erosion and sedimentation, groundwater resources, non-conventional water resources, storage of water and impacts of the water scarcity on the future of the region. The book contains reviews of several topics coupled with case studies, data analyses, discussions and conclusions which apply to several areas of water resources planning, development and management. More than 300 sources of literature are included for reference.Audience: This is a key reference book aimed at researchers, professionals and research students working in the fields of hydrometeorology, engineering hydrology, agriculture hydrology and water quality data. It also serves the interest of those who are interested in water resources development and management in arid and semi-arid zones in general, and in the Arab Region in particular.