Fluid mechanics, an ancient Greek concept, was first introduced by Archimedes around 250 BC. The first law of fluid mechanics, the conservation of mass, states that mass is conserved within a control volume for constant-density fluids. Isaac Newton, an ancient Greek, first described fluid viscosity in his 1687 Principia. The origin of fluid dynamics can be traced back to Leonardo da Vinci, who was educated at Plato's Academy. The Reynolds theory of fluid mechanics explains the relationship between mass and viscosity.
Drought can not be defined as Flood. No single definition is available for drought. The beginning and end of drought are difficult to identify. Drought can be, however, identified through various indicators such as rainfall, snowpack, streamflow, and more, and these indicators can be used to monitor drought. Different scientists and researchers have developed various indices to help determine the onset, severity, and end of droughts. Drought indices are multiparameter and based on long or short duration observation of data for such parameters which help them create a comprehensible big picture. A drought index value is typically a single number that is calculated based on the data of input parameters generally rainfall, snowpack, evapotranspiration, etc., and is interpreted on a scale of abnormally wet, average, and abnormally dry.( Reference ) The video below elaborates the concept : Although drought is very difficult to determine the significance of drought in agriculture, water...