Extensive loess deposits are found in northern China, the Great Plains of North America, central Europe, and parts of Russia and Kazakhstan. The thickest loess deposits are near the Missouri River in the U.S. state of Iowa and along the Yellow River in China.

Extensive, thick loess deposits generally formed in areas bordering large, continental glaciers. Large volumes of meltwater flowed from the edges of these glaciers during the summer. This meltwater carried large amounts of sediments that formed as the glacier ground the bedrock over which it moved.

The wind-blown silt particles that form this deposit were eroded from silty bedrock and transported through the Sand Hills dune field (in the distant background) before encountering the Platter River valley, a topographic break that stopped saltating sand and caused the loess to accumulate.

Sand dunes form when the wind deposits sand. Loess form when the wind deposits clay and silt. Wind erosion can be prevented by keeping the ground covered with plants. They help hold the soil in place.

Water flowing over a steeper slope moves faster and causes more erosion. How water transports particles depends on their size. When water slows down, it starts depositing sediment. This process starts with the largest particles first.

a dune is a hill of sand built by aeolian processes( ie wind) which can travell pretty quickly, Loess is an aeolian sediment which forms by the accumulation of wind-blown silt and lesser and variable amounts of either sand or clay (which covers an area over a lot amount of time).

Wind

Erosion is the transportation of sediment at the Earth’s surface. 4 agents move sediment: Water, Wind, Glaciers, and Mass Wasting (gravity).

Erosion increases the amount of dust carried by wind, which not only acts as an abrasive and air pollutant but also carries about 20 human infectious disease organisms, including anthrax and tuberculosis.

Different Soil Erosion Causes

• 1) Sheet erosion by water;
• 2) Wind erosion;
• 3) Rill erosion – happens with heavy rains and usually creates smalls rills over hillsides;
• 4) Gully erosion – when water runoff removes soil along drainage lines.
• 5) Ephemeral erosion that occurs in natural depressions.

Water runoff is increased, and run off often carries pollutants with it which negatively impact the surrounding land. Other effects of erosion include increased flooding, increased sedimentation in rivers and streams, loss of soil nutrients’ and soil degradation, and, in extreme cases, desertification.

Impacts of erosion

• reduced ability of the soil to store water and nutrients.
• exposure of subsoil, which often has poor physical and chemical properties.
• higher rates of runoff, shedding water and nutrients otherwise used for crop growth.
• loss of newly planted crops.
• deposits of silt in low-lying areas.

15 Wonderful Methods to Control Erosion

• Planting Vegetation. This method involves planting crops with deep roots that can hold the soil in place.
• Contour Farming.
• Applying Mulches.
• Avoiding Overgrazing.
• Reforestation.
• Use Plastic Sheeting.
• Use of Silt Fencing.
• Applying Terraseeding Method.

While controlling soil erosion, vegetative contour hedges of vetiver also conserve soil water by enhancing infiltration and decreasing losses due to runoff. Setaria vetiveria spp. Growing perennial shrubs as contour hedgerows is another commonly used form of vegetative hedge.

Vegetative barrier is a strip planted with a grass or shrub that runs across the slope. It slows down water flowing down the slope and catches the sediment that has been eroded uphill. Over time, soil may build up behind the strip.

Deforestation, which is logging or burning forests, is a way in which humans cause erosion. Removal of the vegetation covering the ground causes the soil, which is unprotected against wind and water, to erode. The loss of topsoil essentially destroys the ability for the land to regenerate.

Vegetation Control is the process of ridding a space of undesired plants, weed and other vegetation.

Definition. Vegetative barriers (also referred to as grass hedges) are narrow, parallel strips of stiff, erect, dense grass planted close to the contour. These barriers cross concentrated flow areas at convenient angles for farming.

Natural vegetative strips (NVS) are narrow live barriers comprising naturally occurring grasses and herbs. Contour lines are laid out with an A-frame or through the ‘cow’s back method’ (a cow is used to walk across the slope: it tends to follow the contour and this is confirmed when its back is seen to be level).

Sheet erosion occurs as a shallow ‘sheet’ of water flowing over the ground surface, resulting in the removal of a uniform layer of soil from the soil surface. Sheet erosion occurs when rainfall intensity is greater than infiltration (sometimes due to crusting). Rarely seen but accounts for large volumes of soil loss.