calcareous - a soil containing enough calcium carbonate to fizz visibly when treated with hydrochloric acid.
delta - an alluvial deposit where a stream or river drops its sediment load on entering a body or more quiet water.
flood plain - nearly level land, consisting of stream sediments, that borders a stream and is subject to flooding unless protected artificially.
irrigation - application of water to soils to assist in the production of crops.
oxbow - when a sharp bend in a river is cut off from a river's course, the meander is separated from the river; the water stops flowing and becomes an oxbow lake.
meander - a sharp bend in a river's course that is cut off by a new channel that forms across the neck of land created by the meander.
soil profile - a vertical section of the soil through all its horizons and extending into the parent material.
resaca - a Spanish term for an abandoned river channel.
terrace (geological) - an old alluvial plain, ordinarily flat or undulating, bordering a river, lake, or the sea.