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LECA is usually produced in different sizes and densities from 0.1 millimetres (0.004 in) up to 25 millimetres (1.0 in), commonly 0–4 mm, 4–10 mm, 10–25 mm and densities of 250, 280, 330, and 510 kg/m 3. LECA boulder is the biggest size of LECA with 100–500 mm size and 500 kg/m 3 density.
where R is the rainfall erosivity factor, K is the soil erodibility, [3] [4] L and S are topographic factors representing length and slope, and C and P are cropping management factors. Other factors such as the stone content (referred as stoniness ), which acts as protection against soil erosion, are very significant in Mediterranean countries.
Dispersion is a process that occurs in soils that are particularly vulnerable to erosion by water. In soil layers where clays are saturated with sodium ions ("sodic soils"), soil can break down very easily into fine particles and wash away. This can lead to a variety of soil and water quality problems, including:
Soil Classification Group Symbol Group Name COARSE-GRAINED SOILS. More than 50% retained on No.200 Sieve Gravels. More than 50% of coarse fraction on No. 4 Sieve Clean Gravels. Less than 5% fines Cu ≥ 4 and 1 ≤ Cc ≤ 3 GW Well-graded gravel Cu < 4 and/or Cc < 1 or Cc > 3 GP Poorly graded gravel Gravels with Fines. More than 12% fines
The Universal Soil Loss Equation (USLE) is a widely used mathematical model that describes soil erosion processes. [1]Erosion models play critical roles in soil and water resource conservation and nonpoint source pollution assessments, including: sediment load assessment and inventory, conservation planning and design for sediment control, and for the advancement of scientific understanding.
The classification system was first developed by Hogentogler and Terzaghi in 1929, [1] but has been revised several times since. AASHTO Soil Classification System (from AASHTO M 145 or ASTM D3282) General Classification
The jet erosion test (JET), or jet index test, is a method used in geotechnical engineering to quantify the resistance of a soil to erosion. The test can be applied in-situ after preparing a field site, or it can be applied in a laboratory on either an intact or a remolded soil sample .
Tillage erosion is the soil movement and erosion by tilling a given plot of land. [3] A similar practice is contour bunding where stones are placed around the contours of slopes. Contour plowing has been proven to reduce fertilizer loss, power, time consumption, and wear on machines, as well as to increase crop yields and reduce soil erosion.