Meaning of Runoff
What is Runoff:
Runoff is a stream of rainwater that circulates over the earth's surface when it passes a natural or surface reservoir. Runoff can also be known as runoff or spillway.
Runoff is a stream of water that originates from precipitation that circulates and spreads over the ground once its evaporation and infiltration capacity has been exceeded.
Therefore, the runoff that travels through the ground and expands freely, is of the utmost importance for humans because it allows, mainly, the collection of water.
Hence, in ancient civilizations water drains were built that were intended to irrigate crops, for the use and consumption of people, generate energy or perform various jobs.
In addition, runoff is what feeds rivers, seas, oceans, reservoirs or basins. Likewise, it is the cause of the erosion of various lands.
Factors Affecting Runoff
It is worth mentioning that runoff is directly affected by four natural factors that are:
Meteorological factor: it varies according to the intensity of rainfall and changes in temperature.
Geographical factor: refers to the geographical area and its morphology.
Hydrogeological factor: refers to the permeability of soils, their layers and depth.
Biological factor: it has to do with the surface of the vegetation and the actions of the human being.
See also Hydrography.
Types of runoff
There are two types of runoff that vary according to their origin, including surface runoff and underground runoff.
Surface runoff is the fastest there is and is the main cause of soil erosion. This derives from precipitation, melting snow and glaciers. These runoffs are those that reach the oceans, rivers and seas. This runoff can also cause various plant damage.
On the other hand, it must be remembered that surface runoffs are also affected by human activity, therefore, they transport garbage, chemicals and other wastes that negatively affect water and the environment.
Underground runoff is that which occurs below the ground once the water has infiltrated. In this case, the water circulates horizontally and can then flow outside again in the form of a spring.
Underground runoff infiltrates the soils at deep levels where it can circulate as drainage. This runoff is much slower than surface runoff.
See also Water cycle (with pictures).