soil science Soil science is the study of soil as a natural resource on the surface of the Earth including soil formation, classification and mapping; physical, chemical, biological, and fertility properties of soils; and these properties in relation to ...

, Horton overland flow describes the tendency of water to flow horizontally across land surfaces when rainfall has exceeded infiltration capacity and

depression storage capacity Soil science is the study of soil as a natural resource on the surface of the Earth including soil formation, classification and mapping; physical, chemical, biological, and fertility properties of soils; and these properties in relation to the ...

. It is named after Robert E. Horton, the engineer who made the first detailed studies of the phenomenon. Paved surfaces such as

asphalt Asphalt, also known as bitumen (, ), is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term ...

, which are designed to be flat and

impermeable Permeability, permeable, and semipermeable may refer to: Chemistry *Semipermeable membrane, a membrane which will allow certain molecules or ions to pass through it by diffusion *Vascular permeability, the movement of fluids and molecules betwe ...

, rapidly achieve Horton overland flow. It is shallow, sheetlike, and fast-moving, and hence capable of extensively eroding

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

and

bedrock In geology, bedrock is solid rock that lies under loose material ( regolith) within the crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface material. An exposed portion of be ...

. Horton overland flow is most commonly encountered in urban construction sites and unpaved

rural In general, a rural area or a countryside is a geographic area that is located outside towns and cities. Typical rural areas have a low population density and small settlements. Agricultural areas and areas with forestry typically are descri ...

roads, where vegetation has been stripped away, exposing bare dirt. The process also poses a significant problem in areas with steep terrain, where water can build up great speed and where soil is less stable, and in

farmland Agricultural land is typically land ''devoted to'' agriculture, the systematic and controlled use of other forms of lifeparticularly the rearing of livestock and production of cropsto produce food for humans. It is generally synonymous with bot ...

s, where soil is flat and loose.

References

* Horton, Robert E. (1933
"The role of infiltration in the hydrologic cycle"
''Transactions of the American Geophysics Union, 14th Annual Meeting, pp. 446–460. * Horton, Robert E. (1945
"Erosional development of streams and their drainage basins; Hydrophysical approach to quantitative morphology"
''Geological Society of America Bulletin'', 56 (3): 275–370.

External links

{dead link, date=January 2018 , bot=InternetArchiveBot , fix-attempted=yes Soil physics Hydrology

See also

References

External links