Physical properties of soil

Natural soil layers showing sand silt and clay composition in a cross section with visible texture differences

Soil physical properties are ranked in importance for ecosystem services like crop production include texture, structure, bulk density, porosity, consistency, temperature, color, and resistivity. Texture depends on the proportions of sand, silt, and clay, while structure refers to how these particles form aggregates. Bulk density indicates compaction, and porosity represents the void spaces that hold air or water. Consistency describes how well soil materials stick together, while temperature and color are straightforward properties. Resistivity measures the soil’s resistance to electrical flow and influences corrosion of buried materials. These properties vary with soil depth and collectively control aeration, water infiltration, and retention (Wikipedia).

Centrifugal pump selection and characteristics

Infographic explaining centrifugal pump selection and characteristics including function, types, and comparison with positive displacement pumps

The basic function of a pump is to do work on a liquid. It can be used to transport and compress a liquid. In industries heavy-duty pumps are used to move water, chemicals, slurry, food, oil and so on. Depending on their action, pumps are classified into two types – Centrifugal pumps and positive displacement pumps. While centrifugal pumps impart momentum to the fluid by motion of blades, positive displacement pumps transfer fluid by variation in the size of the pump’s chamber.

Centrifugal pumps can be of rotor or propeller types, whereas positive displacement pumps may be gear-based, piston-based, diaphragm-based, etc. As a general rule, centrifugal pumps are used with low-viscosity fluids and positive displacement pumps are used with high viscosity fluids. (Wikipedia)

Internal Soil Erosion

Illustration showing internal soil erosion inside an embankment dam where water seepage removes soil particles and forms piping channels

Internal erosion is the formation of voids within a soil caused by the removal of material by seepage. It is the second most common cause of failure in levees and one of the leading causes of failures in earth dams, responsible for about half of embankment dam failures.

Internal erosion occurs when the hydraulic forces exerted by water seeping through the pores and cracks of the material in the dam and/or foundation are sufficient to detach particles and transport them out of the dam structure. Internal erosion is especially dangerous because there may be no external evidence, or only subtle evidence, that it is taking place. Usually, a sand boil can be found, but the boil might be hidden under water. A dam may breach within a few hours after evidence of internal erosion becomes obvious.

Piping is a related phenomenon and is defined as the progressive development of internal erosion by seepage, appearing downstream as a hole discharging water. Piping is induced by regressive erosion of particles from downstream and along the upstream line towards an outside environment until a continuous pipe is formed. (Wikipedia)