A berm is basically "a mound of something somewhere," made out of anything from rubber
and holding everything from poison
to palm trees
. There are five major kinds of berms:
These are typically pallets made to contain spills or waste fluids in a construction environment. There are smaller plastic berms shaped like sandboxes, long foam and vinyl berms to be positioned underneath trucks carrying tanks of fuel or other chemicals, and wider snap-together foam berms that can cover the floor of an entire room if necessary.
This is a method used to build underground homes. There are two types of these, earth bermed and earth sheltered; those using berms have soil built up on one side to protect and insulate them, while earth sheltered homes are covered entirely with soil on the sides and top. There are quite a few pages on this indexed at http://www.liquefaction.com/berm.
This is a berm made out of recycled forest products which can be placed on a construction site instead of a silt fence. It prevents erosion by allowing water to filter through while trapping the silt and other particles which try to flow out.
A heap of earth which can be anywhere from a few inches high to the size of a small hill. In one Naples, Florida project, 32-foot berms were built and covered with "native plantings including oaks, palm trees and shrubs." (http://www.naplesdailynews.com/today/restate2/d152057a.htm)
In addition to being an aesthetic landscaping choice, these berms can also be used to control dust and erosion by blocking wind or foot access to an area prone to soil disturbance. A sufficiently high berm can also provide more room for roots to grow, especially in areas with inhospitable earth. Dirt bike racers also build berms out of hard-packed dirt to make a jump.
This form of berm is defined by the Illustrated Glossary of Geographic Terms as "A small terrace in the backshore area of the coast with its terrace facing seaward."
Essentially, it is a ridge of sand formed by waves. The backshore is that part of a beach where people frolic in the waves, from the edge of the water to the part where it drops off precipitously: that point is a sand berm formed by storm waves, which are much more forceful and dramatic than everyday waves.