Precipitation occurs when a mass of moist air is sufficiently cooled to become saturated, and then condensate. Since, the most important cooling mechanism is due to uplift of air, there are three ways of precipitation causing the vertical air motion:

  • Convective
  • Cyclonic
  • Orographic

Convective precipitation is the most inhomogeneous type of precipitation caused by a rapid ascent of warmed air in a colder, more dense air film. As typical consequence thunderstorms appear which envoke heavy, localized rainfall. Cyclonic precipitation are mostly characterised by a long duration and more homogeneous dispersion. To give an example: cold front about 150 kmē and warm front about 650 kmē.

The amount of precipitation is a very decisive input parameter for hydrological models. However, not only the amount of precipitation but also its spatial and temporal distribution and the form are important to describe the effects of a rainfall event. Forms of rainfall are for example rain drops or sleet, hail and also snow (Figure). As result of this great variety different effects can be observed concerning the soil moisture, the groundwater recharge and river flows of a region.

Different forms of precipitation

Headers and keywords
Page content

< Previous   Next >

< 1 2 3 4 5 6>

page 1 / 6

Hydrological modelling





Full Text

Further Information


Back to > Runoff formation