Tag Archives: ponding
by Michael Dangermond, Senior Digital Cartographer, Esri
The Soil Hydrology of the United States Web Map Application brings some of the most important hydrologic soil properties together in one map. Find hydrologic group codes for hydrologic and hydraulic models. Find hydric soil information to determine wetland land classification. Find depth to the water table for groundwater analysis and well drilling operations.
Of interest to its hydro customers, Esri has web-enabled four more hydro-related soil maps of the United States from the NRCS SSURGO dataset. The source of the data for these maps is the Map Unit Aggregate Attribute table or MUAGGATT.
The new maps released are as follows:
Ponding Frequency – Presence*
The percentage of the map unit that is subject to water being ponded on the soil surface, expressed as one of four classes; 0-14%, 15-49%, 50-74% or 75-100%.
The shallowest depth to a wet soil layer (water table) at any time during the year expressed as centimeters from the soil surface, for components whose composition in the map unit is equal to or exceeds 15%.
The shallowest depth to a wet soil layer (water table) during the months of April through June expressed in centimeters from the soil surface for components whose composition in the map unit is equal to or exceeds 15%.
The distance from the soil surface to the top of a bedrock layer, expressed as a shallowest depth of components whose composition in the map unit is equal to or exceeds 15%.
In addition to the new maps, some changes were made to the cartography
on the previously released maps entitled Drainage Class-Dominant
Condition and Drainage Class-Wettest. In these webmaps, the new color
scheme has been improved to allow for an easier comparison of soil
drainage characteristics. With the new scheme it is now much easier to
read whether soil drains too much or too little (according to NRCS’
existing classification scheme), and how much or how little in
comparison to neighboring soils.
*These maps are ready to use, but are still beta products at the moment. They will undergo further review, so keep in mind that map colors and the contents page are subject to change. The data is in the same state it was since being provided by the NRCS. So, the data itself is not subject to change, only the cartography and the web medium.
Special thanks to Michael Dangermond for providing the post. Questions for Michael: MDangermond@esri.com.