Available Water Supply, 0 to 100 cm Depth
National Park Service: Thomas Colson. 2011. Available Water Supply, 0 to 100 cm Depth
Available water supply (AWS) is the total volume of water (in centimeters) that should be available to plants when the soil, inclusive of rock fragments, is at field capacity. It is commonly estimated as the amount of water held between field capacity and the wilting point, with corrections for salinity, rock fragments, and rooting depth. AWS is reported as a single value (in centimeters) of water for the specified depth of the soil. AWS is calculated as the available water capacity times the thickness of each soil horizon to a specified depth. For each soil layer, available water capacity, used in the computation of AWS, is recorded as three separate values in the database. A low value and a high value indicate the range of this attribute for the soil component. A "representative" value indicates the expected value of this attribute for the component. For the derivation of AWS, only the representative value for available water capacity is used. The available water supply for each map unit component is computed as described above and then aggregated to a single value for the map unit by the process described below. A map unit typically consists of one or more "components." A component is either some type of soil or some nonsoil entity, e.g., rock outcrop. For the attribute being aggregated (e.g., available water supply), the first step of the aggregation process is to derive one attribute value for each of a map unit's components. From this set of component attributes, the next step of the process is to derive a single value that represents the map unit as a whole. Once a single value for each map unit is derived, a thematic map for the map units can be generated. Aggregation is needed because map units rather than components are delineated on the soil maps. The composition of each component in a map unit is recorded as a percentage. A composition of 60 indicates that the component typically makes up approximately 60 percent of the map unit. For the available water supply, when a weighted average of all component values is computed, percent composition is the weighting factor.
- Type
- Geospatial Dataset
- Authors
- National Park Service: Thomas Colson
- Date of Issue
- 2011-10-10
- Units
- GRSM
- Keywords
- APHN, Appalachian Highlands Network, available water supply, Blockhouse TN, Blount County, Bryson City NC, Bunches Bald NC, Cades Cove TN, Calderwood TN, Clingmans Dome NC, Cocke County, Cove Creek Gap NC, Dellwood NC, Environment, Fines Creek NC, Fontana Dam NC, Gatlinburg TN, Graham County, Great Smoky Mountains National Park, GRSM, Hartford TN, Haywood County, Jones Cove TN, Kinzel Springs TN, Luftee Knob NC, Mount Guyot TN, Mount Le Conte TN, National Standards for Spatial Digital Accuracy (NSSDA), Natural Resource Inventory And Monitoring Program, NC, Noland Creek NC, None, North Carolina, NRIM, Pigeon Forge TN, Richardson Cove TN, SERO, Sevier County, Silers Bald NC, Smokemont NC, Soil Survey, Soil Survey Geographic, Soils, Southeast Region, SSURGO, Swain County, Tallassee TN, Tapoco NC, Tennessee, Thunderhead Mountain NC, TN, Tuskeegee NC, U.S., United States, US, USA, Waterville TN, Wear Cove TN, Whittier NC