Water is essential to all forms of life and is regarded as the most important and exploited natural resource in the world. Water moves through and is stored in different compartments of the Earth environment (atmosphere, glaciers, vegetation, soil, shallow and deep subsurface, rivers, lakes and oceans) at different velocities and quantities respectively, strongly controlled by current and past hydrometeorological and geological conditions. Understanding and quantification of the quantitative and qualitative aspects of the typical physical processes like precipitation, evaporation, transpiration, interception, infiltration, runoff, recharge, surface water and groundwater discharge form the fundamental components of the hydrological sciences....