The Mapunit Aggregated Attribute table records a variety of soil attributes and interpretations that have been aggregated from the component level to a single value at the map unit level. They have been aggregated by one or more appropriate means in order to express a consolidated value or interpretation for the map unit as a whole. One field that is very useful for Storm Water Runoff is the HYDGRPDCD (Hydrologic Group - Dominant Conditions),which is a grouping of soils that have similar runoff potential under similar storm and cover conditions. This column displays the dominant hydrologic group for the map unit, based on composition percentage of each map unit component.
Below is the domain values and descriptions for this field:
A-- Soils in this group have low runoff potential when thoroughly wet. Water is transmitted freely through the soil.
B-- Soils in this group have moderately low runoff potential when thoroughly wet. Water transmission through the soil is unimpeded.
C-- Soils in this group have moderately high runoff potential when thoroughly wet. Water transmission through the soil is somewhat restricted.
D-- Soils in this group have high runoff potential when thoroughly wet. Water movement through the soil is restricted or very restricted.
A/D-- These soils have low runoff potential when drained and high runoff potential when undrained.
B/D-- These soils have moderately low runoff potential when drained and high runoff potential when undrained.
C/D-- These soils have moderately high runoff potential when drained and high runoff potential when undrained.
For more information about the different columns for this table click on MUAGGATT, and search this pdf for this table name, and for even more information about Soil Survey and SSURGO click here. You can view the Knox County Soil Survey Manuscript here.
I set up a relationship class with the soil survey feature class and the mapunit aggregate table, this enables ArcMap users to add the soil feature class (KGIS.ENV_SoilSurvey_KNO) and when you identify on a soil type the related data from the ENV_Muaggatt_KNO will show up in the identify window with the soil data. If you want to label off this table then you will need to join this table to the feature class and use the MUKEY field for your join field.
Please contact me if you need help accessing this data or if you have any questions.
Chris Halcomb 215-3906