Reference Work Entry

Encyclopedia of World Climatology

Part of the series Encyclopedia of Earth Sciences Series pp 415-420


  • Wayne M. Wendland

Hydroclimatology was defined by Langbein (1967) as the study of the influence of climate upon the waters of the land. It includes hydrometeorology as well as the surface and near-surface water processes of evaporation, runoff, groundwater recharge, and interception. The total hydrologic cycle, then, is the basis for a discussion of hydroclimatology.

The water budget equation based on conservation of mass is given as:

where P is precipitation, R is streamflow, ET is evapotranspiration, U is subsurface underflow, ΔSs is the change in soil moisture, ΔSg the change in groundwater storage, and I is interception. When the equation is evaluated using annual mean data, the changes in groundwater storage, soil moisture and subsurface underflow are assumed to be zero; and if the interception is sufficiently small, all four terms may be deleted. Although the components of the total budget are easy to list, quantification of each of the components over various time scales is always difficult, and s ...

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