INTRODUCING A NEW INDEX OF SOIL WETNESS, AND ITS POTENTIAL AS A LANDSCAPE/LANDFORM VISUALIZATION TOOL

Soil maps and data can be highly useful for Quaternary and surficial mapping projects of all kinds, as they typically contain a great amount of detail on surficial sediments. However, soils data can be unwieldy and difficult to interpret for many users, even within a GIS. We are introducing a new index of soil wetness, called the Natural Soil Drainage Index (DI). The DI is intended to reflect the amount of useable water that a soil can supply to growing plants under natural conditions. It operates on the assumption that soils in drier climates and with deeper water tables have less plant-useable water, other things being equal. The DI ranges from 0 for the very driest soils, e.g., those shallow to bedrock in a desert, to 99, for areas of open water, and can be calculated for any soil by knowing it's taxonomic subgroup. In this poster we highlight the correlations among DI values and Quaternary geology, for various parts of the United States, using the US General Soil Map configured in color to relect DI values. Equally useful applications could be realized using state- and regional-level soils data. For more information, please visit: http://www.drainageindex.msu.edu/