textural classes
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saska.vidmar
- Posts: 1
- Joined: Wed Feb 03, 2010 6:56 am
- Location: Slovenia
textural classes
Inside the program used textural classes are defined as sand and smaller particles. How do we take into account grain sizes bigger than sand (gravel, pebbles)? Do we just assume a 100% composition of smaller particles? Have there been any known problems as a result of this?
Saska:
There have been a number of studies suggesting that you can make a simple linear correction to the water retention curve (e.g., as predicted with pedotransfer functions, or measured) to account for the gravel content (i.e., by assuming that gravel contains no water); just correct the saturated and residual water contents. Corrections of the hydraulic conductivity are a bit more complicated. A good recent study is by Dann et al. in Vadose Zone Journal (2008, 8:651–663, doi:10.2136/vzj2008.0174). Look also at Khaleel and Relyea, 1997 (Correcting laboratory-measured moisture retention data for gravels. Water Resour. Res. 33:1875–1878), and references in those two papers.
Rien van G.
There have been a number of studies suggesting that you can make a simple linear correction to the water retention curve (e.g., as predicted with pedotransfer functions, or measured) to account for the gravel content (i.e., by assuming that gravel contains no water); just correct the saturated and residual water contents. Corrections of the hydraulic conductivity are a bit more complicated. A good recent study is by Dann et al. in Vadose Zone Journal (2008, 8:651–663, doi:10.2136/vzj2008.0174). Look also at Khaleel and Relyea, 1997 (Correcting laboratory-measured moisture retention data for gravels. Water Resour. Res. 33:1875–1878), and references in those two papers.
Rien van G.