In water-related science and engineering, there are two similar but distinct definitions in use for the word drawdown: . In subsurface hydrogeology, drawdown is the reduction in hydraulic head observed at a well in an aquifer, typically due to pumping a well as part of an aquifer test or well test.; In surface water hydrology and civil engineering, drawdown refers to the lowering of the ...

In hydrology, discharge is the volumetric flow rate of water that is transported through a given cross-sectional area. It includes any suspended solids (e.g. sediment), dissolved chemicals (e.g. CaCO 3(aq)), or biologic material (e.g. diatoms) in addition to the water itself.Terms may vary between disciplines. For example, a fluvial hydrologist studying natural river systems may …