Ice sheet s there can be more than a mile thick, making it difficult for scientists to measure the speed and patterns of erosion. However, ice sheets do erode remarkably quickly—as much as half a centimeter.
Thermal erosion describes the erosion of permafrost along a river or coastline. Warm temperature s can cause ice-rich permafrost to break off coastlines in huge chunks, often carrying valuable topsoil and vegetation with them. Mass wasting describes the downward movement of rocks, soil, and vegetation. Mass wasting incidents include landslides, rockslides, and avalanche s. Mass wasting can erode and transport millions of tons of earth, reshaping hills and mountains and, often, devastating communities in its path.
Some of the natural factors impacting erosion in a landscape include climate, topography, vegetation, and tectonic activity. Climate is perhaps the most influential force impacting the effect of erosion on a landscape. Climate includes precipitation and wind.
Climate also includes seasonal variability, which influences the likelihood of weathered sediments being transported during a weather event such as a snowmelt, breeze, or hurricane. Topography , the shape of surface features of an area, can contribute to how erosion impacts that area. The earthen floodplains of river valleys are much more prone to erosion than rocky flood channels, which may take centuries to erode.
Soft rock like chalk will erode more quickly than hard rocks like granite. Vegetation can slow the impact of erosion. Plant roots adhere to soil and rock particles, preventing their transport during rainfall or wind events. Trees, shrub s, and other plants can even limit the impact of mass wasting events such as landslides and other natural hazards such as hurricanes.
Deserts, which generally lack thick vegetation, are often the most eroded landscapes on the planet. Finally, tectonic activity shapes the landscape itself, and thus influences the way erosion impacts an area. Tectonic uplift , for example, causes one part of the landscape to rise higher than others.
In a span of about 5 million years, tectonic uplift caused the Colorado River to cut deeper and deeper into the Colorado Plateau, land in what is now the U. It eventually formed the Grand Canyon, which is more than 1, meters 1 mile deep and as much as 29 kilometers 18 miles wide in some places. Eroded sediments have profoundly influenced the development of civilization s around the world.
Agricultural development is often reliant on the nutrient -rich soils created by the accumulation of eroded earth. When the velocity of wind or water slows, eroded sediment is deposited in a new location.
The sediment builds up in a process called sedimentation and creates fertile land. River delta s are made almost entirely of sediment that has eroded from the banks and bed of a river.
The rich delta soils of the San Joaquin and Sacramento rivers in northern California, for example, have created one of the most agriculturally productive areas in the world. Loess is an agriculturally rich sediment made almost entirely of wind-blown, eroded sediment. The Yellow River in central China gets its name from the yellow loess blown into and suspended in its water. Human activity altering the vegetation of an area is perhaps the biggest human factor contributing to erosion.
Trees and plants hold soil in place. When people cut down forests or plow up grasses for agriculture and development, the soil is more vulnerable to washing or blowing away. Landslides become more common. Water rushes over exposed soil rather than soaking into it, causing flooding.
Global warming , the current period of climate change , is speeding erosion. The change in climate has been linked to more frequent and severe storms. Storm surge s following hurricanes and typhoon s can erode kilometers of coastline and coastal habitat. These coastal areas are home to residences, businesses, and economically important industries, such as fisheries.
The rise in temperature is also quickly melting glaciers. The slower, more massive form of glacial erosion is being supplanted by the cumulative impact of rill, gully, and valley erosion.
In areas downstream from glacial snouts, rapidly melting glaciers are contributing to sea level rise. The rising sea erodes beaches more quickly. Erosion control is the process of reducing erosion by wind and water. Farmer s and engineer s must regularly practice erosion control. Sometimes, engineers simply install structures to physically prevent soil from being transported.
Gabion s are huge wireframes that hold boulders in place, for instance. Gabions are often placed near cliffs. Suspension: After the saltation begins, the particles hit the surface and knock loose other particles, knocking them into the air. These include smaller sand particles and clays. They then are lifted into the atmosphere and can be transported long distances until the wind speed decreases.
Wise use of our soils requires us to minimize erosion. The best way to control water erosion involve slowing down the flow of water and limiting soil detachment. The best way to prevent this is to keep the soil covered with either growing plants or residues from past crops.
These absorb the energy from raindrops and slow the rate of water flow over the surface, allowing more time to have water infiltrate through the soil.
Tillage is very important in agriculture, but there are several best management practices that can help reduce erosion. Using cover crops, filter strips, contour farming and conservation tillage, and riparian buffers can help reduce or eliminate soil movement.
Minimum and no till systems help with both types of erosion. Erosion Facts and Conservation. Water Erosion and Conservation. Wind Erosion and Conservation. For high school and introductory college students, gain a foundation about the world of soils with our book - Know Soil, Know Life. Visit the Society Store to learn more and purchase your copy today.
Breadcrumb Home. The result of this would be flooding in the long run. The eroded soil material can either form a new soil or move to water reservoirs nearby lakes, streams, etc.
Depending on the cause of its occurrence, land depletion by water can be either natural or accelerated. Natural water erosion is beyond human control and does not have a significant effect on soil fertility.
It is caused by rainfall, melted snow, or runoff, i. Each soil type has its natural erosion rate, depending on farmland properties and the climate in which it is located. On the contrary, accelerated erosion is the consequence of irrational farming. It occurs when the wrong choice of irrigation method, amount of water, and the time of its application result in the destruction of the fertile layer of land. Land depletion caused by water occurs in several stages and is manifested in different ways according to the factors that caused it.
Below are the common water erosion types that can affect soil if not prevented promptly. This is the first stage in the erosion process that is caused by rain.
Eventually, it causes the formation of surface crusts, negatively affects soil infiltration ability, and eventually results in runoff formation. This type of soil degradation by water occurs when the rainfall intensity is greater than the soil infiltration ability and results in the loss of the finest soil particles that contain nutrients and organic matter. It usually follows after crusting that is caused by the previous stage of soil damage by water.
If not prevented timely, one of the most negative effects of sheet erosion will be the formation of rills. Rill erosion follows after, when the water concentrates deeper in the soil and starts forming faster-flowing channels. These channels can be up to 30cm deep and cause detachment and transportation of soil particles.
Rill erosion can eventually evolve into gully erosion. That is when the rills become at least 0. Apart from causing huge soil losses and destroying farmland, it also results in reduction of water quality by increasing the sediment load in streams. It begins when large water mass starts moving through the structurally unstable soil. That is why it is usually the biggest threat to sodic soil.
The manifestations of tunneling would be a series of tunnels beneath the soil surface. Despite the diversity of manifestations, all types of water erosion cause a common set of negative effects that can be defined.
Some rocks dissolve more easily than others. Over time, the water may dissolve large underground holes, or caves. Groundwater drips from the ceiling to the floor of a cave. This water is rich in dissolved minerals. When the minerals come out of solution, they are deposited. They build up on the ceiling of the cave to create formations called stalactites. A stalactite is a pointed, icicle-like mineral deposit that forms on the ceiling of a cave.
They drip to the floor of the cave and harden to form stalagmites. A stalagmite is a more rounded mineral deposit that forms on the floor of a cave Figure below. Both types of formations grow in size as water keeps dripping and more minerals are deposited.
As erosion by groundwater continues, the ceiling of a cave may collapse. The rock and soil above it sink into the ground. This forms a sinkhole on the surface. You can see an example of a sinkhole in Figure below. Some sinkholes are big enough to swallow vehicles and buildings. Make a table that relates particle size to the way particles are transported by flowing water.
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