This dislodges soil and when spread evenly over the surface of the soil can erode soil in sheets. This can happen with the first impact of rain hitting the soil and can also happen when water does not channel, but rather moves evenly down a slope. Subscribe to the Safeopedia newsletter to stay on top of current industry trends and up-to-date know-how from subject matter authorities.
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Drunk Driving. Safeopedia Terms. Meet the Author with Robert J. De Boer. 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. The removal of topsoil due to the fast land degradation process will inevitably affect the plants that grow there. The reduction of nutrients that were washed out from the soil by the excess water will prevent crops from receiving the necessary amount of needed elements that decreases their performance.
The absence of the topsoil surface leads to water pollution due to chemical runoff, negatively affecting animals, fish and algae in the area.
Eventually, this leads to reduction of the animal population. Severe land degradation by water can negatively impact the ecosystems by causing flooding. The washed away topsoil loses its water absorption ability , greatly increasing the possibility of flooding in areas that are predisposed to it. It could be low-lying landscapes and soils with limited drainage ability.
Ultimately, heavy flooding can be extremely disruptive to the extent of ruining roads and buildings. Apart from affecting animals, plants, and farmland, water erosion also significantly decreases the quality of water itself. Problems can also occur at the end of a flood event when slow moving water flows over saturated soils. Mass movement occurs on cleared slopes in coastal areas. Gravity moves earth, rock and soil material downslope both slowly millimetres per year and suddenly e.
During periods of prolonged and heavy rainfall, water entering permeable soils can be stopped by a barrier such as bedrock or a clay-rich soil horizon. The heavy weight of this saturated soil can slide downslope if it is sitting on a rock surface loosened by the build-up of water in the soil. It is better to prevent landslides than pay for expensive, time-consuming rehabilitation which may only be partially effective.
As excessive water intake is the most common trigger of landslip, avoid obstructions such as dams or cross-slope drains. It is most likely to occur when strong winds blow over light-textured soils that have been heavily grazed during drought periods.
These areas, which vary from a few square metres to hundreds of hectares, are difficult to revegetate due to:. Generally, wind erosion is not a serious issue in cropping areas. Most soils cultivated in Queensland have a heavy texture—forming relatively large aggregates that are too coarse to be carried by strong winds.
However, sandy soils are vulnerable to wind erosion because they cannot store very much moisture and have low fertility. This limits their use in Queensland, with only small areas where irrigation is available being cultivated for horticulture or growing vegetables.
Home Environment, land and water Land, housing and property Land and vegetation management Soil management Erosion Types of erosion. Print Types of erosion Soil erosion is a widespread problem in rural and urban Queensland. The vulnerability of soils to water erosion depends on: rainfall intensity erosivity —high intensity rainfall creates serious risk as heavy drops on bare soil causes the soil surface to seal nature of the soil erodibility —clay soils vary in their ability to withstand raindrop impact slope length—if a slope is long, water running down the slope becomes deeper and moves faster, taking more soil with it slope steepness—the speed of runoff increases on steep slopes, which increases the power of water to break off and carry soil particles.
Rill and sheet erosion on a cultivated paddock. Scalded landscape, Western Queensland. A highly eroded gully. Tunnel erosion in Marburg, Queensland. Severe stream bank erosion.
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