Where does wash collide?

The removal and transport of soil and sediment by a thin, unconfined film of water spreading across a slope rather than running in a defined channel. McGee's 1897 Sheetflood erosion named this action after observing broad, shallow floods that swept sediment over desert plains without cutting a channel, and Horton's 1945 Erosional development of streams and their drainage basins later set it within a quantitative account of how such flow crosses a hillslope before it gathers into channels. The referent here is a moving process that strips and carries material across a surface, which is distinct from the dry channel that such water can eventually carve, from a diluted layer of paint, and from a paired trade in a market.[1][2]

Unit

A rate of surface lowering or sediment yield per unit area over a slope

Recovery means

Deposition resumes where the flow slows and thins, laying down the material it carried

Measured by

Estimated from erosion plots, sediment traps, and slope surveys that track material moved by unchannelled flow

A trade, or matched pair of trades, in which the same party is effectively on both sides, so that ownership does not really change but the market records apparent activity. Allen and Gale's 1992 Stock-price manipulation set such trade-based tactics within a formal account of how a trader can move a price without holding a genuine position or new information. In tax law the related wash sale is a sale and quick repurchase of the same holding that leaves the position unchanged. The referent is an economic action, a self-cancelling transaction meant to mislead, and it bears no relation to water crossing a slope, a dry channel, or a layer of paint.[3]

Unit

A single self-offsetting trade or matched pair, by volume and value

Recovery means

Not applicable

Measured by

Detected by matching counterparties, timing, and account links that reveal offsetting orders