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Lightweight expanded clay aggregate (LECA) or expanded clay (exclay) is a lightweight aggregate made by heating clay to around 1,200 °C (2,190 °F) in a rotary kiln. The heating process causes gases trapped in the clay to expand, forming thousands of small bubbles and giving the material a porous structure.
About 4,500 soil families are recognised in the United States. [7] A family may contain several soil series which describe the physical location using the name of a prominent physical feature such as a river or town near where the soil sample was taken. An example would be Merrimac for the Merrimack River in New Hampshire. More than 14,000 soil ...
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.
For example, GW-GM corresponds to "well-graded gravel with silt." If the soil has more than 15% by weight retained on a #4 sieve (R #4 > 15%), there is a significant amount of gravel, and the suffix "with gravel" may be added to the group name, but the group symbol does not change. For example, SP-SM could refer to "poorly graded SAND with silt ...
The National Cooperative Soil Survey Program (NCSS) in the United States is a nationwide partnership of federal, regional, state, and local agencies and institutions. This partnership works together to cooperatively investigate, inventory, document, classify, and interpret soils and to disseminate, publish, and promote the use of information about the soils of the United States and its trust ...
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 .
soil type and structure. For example, sandy soil holds little water while clay soils have high water-retention rates; the amount of water used by the plants/crops; how much nitrate is already present in the soil. [3] The level of nitrous oxide (N 2 O) in the Earth's atmosphere is increasing at a rate of 0.2 to 0.3% annually.
Most soil erosion models consider only soil erosion by water, however a few aim to predict wind erosion. Models which consider tillage erosion are rare. Also soil erosion models have been more commonly developed for use on agricultural landscapes, rather than on naturally vegetated areas (such as rangeland or forests).