You have at least once heard about runoff. But until now, you don’t know what does mean by runoff water, its types, effects and factors. Today I will give you the correct definition and answer your these questions.
Runoff is the quantity of water that flows through the subsurface of the earth to any specific area or reservoir. Runoff is a portion of the hydrological water cycle.
Mainly there are three kinds of stormwater losses from the ground, evaporation directly to the atmosphere, infiltration of water to subsoil due to the permeability of soil and water flowing through the subsurface to reservoir or catchment.
The various sources of runoff are rainfall, melting of ice and capillary water. Capillary water involves only a small amount. Capillary water is water rises from the soil due to the pore pressure in the soil and later contributes to runoff. Runoff due to capillary water can be avoided during the measurement of runoff.
The runoff can be expressed in
- Centimeters of water over the catchment
- The total water in hectare-m, cu-m for a given reservoir or catchment.
What are the factors affecting runoff?
The first factor affecting runoff is the amount of rainfall. Because formation of runoff mainly occurs during rainfall. The amount of runoff occurred in a specific region is proportional to the amount of rainfall in that region.
2.Permeability of the soil
The quantity of runoff flowing through the subsurface of the ground is inversely proportional to the permeability of the soil. The permeability depends on the void ratio and porosity of the soil.
3.Slope of the ground.
The more slope, the runoff will be more.Because in greater slope surfaces the water will flow towards the reservoir without much going into the soil.
What are systems that contribute to the runoff water or types of runoff?
The basin recharge consist of following
- Rain obstructed by rain and stems
- Depression storage(Water held in the depression of ground)
- Capillary water in soil due to pore pressure.
The last types of runoff is direct runof f.Direct runoff consists of over land and interflow.Overland flow is water flows on the surface of the ground and interflow is the water flows through soil at the initial stage but later enters into reservoir or catchment.The interflow happens in areas having a steep slope.
What are the effects of runoff?
1.Pollution of coastal areas
The effects of runoff mainly lead to pollution of coastal and marine areas.When rainfall occurs, all the salts, mineral, plastics and other wastes flow towards the coastal areas.This eventually results in the accumulation of wastes in river and oceans.
2.Erosion of the land
When the stormwater hits on steep slope areas, the topsoil will also start moving with the runoff will ultimately lead to erosion of the land surface.These are the effects of runoff.
Hope you can understand Ruoff, effect of runoff and factors affecting runoff water.If you want you to read more civil engineering topics go to our site home section.