What is soil erosion? Soil erosion is a natural process, occurring over geological time, and indeed it is a process that is essential for soil formation in the first place. With respect to soil degradation, most concerns about erosion are related to accelerated erosion, where the natural rate has been significantly increased mostly by human activity. Soil erosion by water is a widespread problem throughout Europe. Soil is naturally removed by the action of water or wind: such 'background' (or 'geological') soil erosion has been occurring for some 450 million years, since the first land plants formed the first soil. Even before this, natural processes moved loose rock, or regolith, off the Earth's surface, just as has happened …show more content…
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Diffuse overland flow. Note the raindrop impacts
Firstly, if rain arrives too quickly (i.e. with too high an intensity) for it to infiltrate: the runoff which results is then known as infiltration excess runoff, or Hortonian runoff. Secondly, runoff may occur if the soil has already absorbed all the water it can hold (i.e. because it is fully saturated, or if the soil is frozen). Runoff which results from this situation is known as saturation excess runoff. As runoff moves downhill, it is at first a thin diffuse film of water which has lost virtually all the kinetic energy which it possessed as falling rain. Thus it moves only slowly, has a low flow power, and is generally incapable of detaching or transporting soil particles.
The micro topography (i.e. small-scale pattern of irregularities) of the soil’s surface tends to cause this overland flow to concentrate in closed depressions, which slowly fill: this is known as ‘detention storage’ or ‘ponding’. Both the flowing water, and the water in detention storage, protect the soil from raindrop impact, so that rainsplash redistribution usually decreases over time within a storm, as the depth of surface water increases. There are, however, complex interactions between rainsplash and overland flow. If rain continues, the increasing depth of water will eventually overtop the micro topographic depressions. Overland flow that is released in this way is likely to flow downhill more quickly and
5. Although there is very little rainfall in deserts, running water is still the most important process of erosion and deposition in arid environments. Describe and explain at least two special conditions in deserts that tend to increase the likelihood of fluvial erosion whenever it does rain.
Stormwater is water produced by rain or melting snow, which can rapidly flow over impervious surfaces into streams. Upland development magnifies the occurrence of stream bank erosion and in-stream nutrient pollution, which also have indirect negative effects. When stream bank erosion occurs, eroding sediment causes an increase in turbidity. Heavy stormwater flows into streams mixes the streambed sediment, which also increases turbidity, and ultimately causes declines in aquatic biota (Waters 1995). Therefore, negative externalities of upland development include
The vegetation surface type affects runoff since it is in contact with the soil. Once the soil absorbs all the water it can hold, the rest undergoes runoff. Through force of gravity, it moves downslope to other areas, carrying soil particles and sediments along. However, more vegetation cover results in less runoff while less cover results in more soil erosion.
A catchment is an area where water is collected by the natural landscape. In a catchment, rain will eventually flow to a dam, creek, river, lake or ocean, evaporate, be used by vegetation and animals or seep into the groundwater system.
Soil Erosion - When the top layer of soil is worn down due to too much water, ice, or wind.
Extracted soil samples indicate simultaneous reduction of rainfall and occasional erosion. Both soil and sediment features show establishment of marked
Storm water runoff is created when rain falls on paved surfaces that do not allow water to soak into the ground, leading to water moving across the surface of the ground. Storm water runoff takes rain water and flows until it can find a stream or large water source, when the water does this is picks up and carries all types
Erosion is a process where natural forces like water, wind, ice, and gravity wear away rocks and soil. Erosion occurs at the Earth’s surface, and has no effect on the Earth’s mantle and core. Water erosion is the removal of soil particles by heavy rainfall or running water. “While the causes of erosion by water are generally natural, water erosion is usually caused by rainfall and runoff on a slope” (GEI Works Erosion Pollution). “The process of water erosion usually occurs on stream and river banks, sea shores and seaside cliffs” (Reference.com).
Storm water runoff gets formed by man-made areas such as driveways, parking areas and roofs. All of these types of surfaces are waterproof surfaces, so when they are placed around lakes, they tend to collect and transport precipitation over the land instead of allowing the water to penetrate into the soil. Storm water runoff affects the soil greatly along with all of the wild life and vegetation that needs the soil to live and form. That is the reason that areas of land around the lakes in Michigan have soil with lesser value than other
The Denver Basin has a semi arid atmosphere in which potential yearly evaporation is around five times greater than yearly precipitation. Most of the precipitation that falls on the land surface either runs off in streams, is evaporated from the surface of the soil, or is consumed by vegetation. Although that may be the case, a little part of the precipitation more often than not diffuses downwards and recharges the groundwater system. In the Denver Basin, a lot of the recharge happens in the highland areas between stream channels in the higher southern part of the basin. Precipitation is more prominent here, and the porous soils derived from the Dawson Arkose allow deep permeation. Recharge here can happen on a local and a regional scale. Locally, water moves from the highland recharge areas
When this is happening it can take out cars, trucks, buses and sometimes-small houses. All this water flows down to the Colorado River. This is more like a fast flowing concrete because after all the raining and water flow the ground gets so hot that it just hardens into one block like concrete.
Soil organisms provide ecosystem services such as maintaining soil fertility and preventing soil erosion. Water, wind, ice, and other agents cause soil erosion, the wearing away or removal of soil from the land. Soil erosion reduces fertility because essential minerals and organic matter are removed. Erosion causes sediments and pesticide and fertilizer residues to pollute nearby waterways ( Wiley, 2009).
When it rains, forests sequester the water, gradually releasing it into streams over the course of several months, and preventing floods. When a forest is cut down, air quality, especially around cities, is lost, and an area’s biodiversity drastically diminishes. Rather than being absorbed by trees, annual rains cause floods. These floods remove soil that was previously held in place by forests, leading to increased erosion and
Erosion removes the surface soils, containing most of the organic matter, plant nutrients, and fine soil particles, which help to retain water and nutrients in the root zone where they are available to plants. Thus it affects the productivity of plants. The remaining, the subsoil, tends to be less fertile, less absorbent and less able to retain pesticides, fertilizers, and other plant nutrients. There are over 17,000 soil types recognized worldwide. They vary widely in structure, erodibility, fertility, and ability to produce crops. A generalized soil profile for a humid, temperate climate is showed. When the natural vegetation is cleared for agriculture, soils become exposed to erosion and loss of soil fertility. The removal of the above-ground natural
Significantly, desertification also cause soil erosion, which means soil surface is worn by wind and water. Desertification makes soil easy to erode by water or wind, as soil is exposed and soil structure is instable without forest. LaI R(2003) says that ““Land area globally affected by erosion is 1094 million ha (Mha) by water erosion, of which 751 Mha is severely affected, and 549 Mha by wind erosion, of which 296 Mha is severely affected.” To control soil erosion, an obvious way is virescence, enlarging forest cover, which can protect the soil far from exposing to strong wind. Also, the roots of plants under ground play a role as a framework, as they are obstructions to soil movement,