Soils Hydric Rating

<div style='text-align:Left;'><div><div><p style='margin:0 0 0 0;'><span><span>This rating indicates the percentage of map units that meets the criteria </span></span></p><p style='margin:0 0 0 0;'><span><span>for hydric soils. Map units are composed of one or more map unit components </span></span></p><p style='margin:0 0 0 0;'><span><span>or soil types, each of which is rated as hydric soil or not hydric. Map units </span></span></p><p style='margin:0 0 0 0;'><span><span>that are made up dominantly of hydric soils may have small areas of minor </span></span></p><p style='margin:0 0 0 0;'><span><span>nonhydric components in the higher positions on the landform, and map units </span></span></p><p style='margin:0 0 0 0;'><span><span>that are made up dominantly of nonhydric soils may have small areas of minor </span></span></p><p style='margin:0 0 0 0;'><span><span>hydric components in the lower positions on the landform. Each map unit is </span></span></p><p style='margin:0 0 0 0;'><span><span>rated based on its respective components and the percentage of each component </span></span></p><p style='margin:0 0 0 0;'><span>within the map unit. </span></p><p style='margin:0 0 0 0;'><span /></p><p style='margin:0 0 0 0;'><span><span>The thematic map is color coded based on the composition of hydric components. </span></span></p><p style='margin:0 0 0 0;'><span><span>The five color classes are separated as 100 percent hydric components, 66 to </span></span></p><p style='margin:0 0 0 0;'><span><span>99 percent hydric components, 33 to 65 percent hydric components, 1 to 32 percent </span></span></p><p style='margin:0 0 0 0;'><span>hydric components, and less than one percent hydric components.</span></p><p style='margin:0 0 0 0;'><span /></p><p style='margin:0 0 0 0;'><span><span>In Web Soil Survey, the Summary by Map Unit table that is displayed below the </span></span></p><p style='margin:0 0 0 0;'><span><span>map pane contains a column named 'Rating'.In this column the percentage of each </span></span></p><p style='margin:0 0 0 0;'><span>map unit that is classified as hydric is displayed.</span></p><p style='margin:0 0 0 0;'><span /></p><p style='margin:0 0 0 0;'><span><span>Hydric soils are defined by the National Technical Committee for Hydric Soils (NTCHS) </span></span></p><p style='margin:0 0 0 0;'><span><span>as soils that formed under conditions of saturation, flooding, or ponding long enough </span></span></p><p style='margin:0 0 0 0;'><span><span>during the growing season to develop anaerobic conditions in the upper part (Federal </span></span></p><p style='margin:0 0 0 0;'><span><span>Register, 1994). Under natural conditions, these soils are either saturated or </span></span></p><p style='margin:0 0 0 0;'><span><span>inundated long enough during the growing season to support the growth and reproduction </span></span></p><p style='margin:0 0 0 0;'><span>of hydrophytic vegetation. </span></p><p style='margin:0 0 0 0;'><span /></p><p style='margin:0 0 0 0;'><span><span>The NTCHS definition identifies general soil properties that are associated with </span></span></p><p style='margin:0 0 0 0;'><span><span>wetness. In order to determine whether a specific soil is a hydric soil or nonhydric </span></span></p><p style='margin:0 0 0 0;'><span><span>soil, however, more specific information, such as information about the depth and </span></span></p><p style='margin:0 0 0 0;'><span><span>duration of the water table, is needed. Thus, criteria that identify those estimated </span></span></p><p style='margin:0 0 0 0;'><span><span>soil properties unique to hydric soils have been established (Federal Register, 2002). </span></span></p><p style='margin:0 0 0 0;'><span><span>These criteria are used to identify map unit components that normally are associated </span></span></p><p style='margin:0 0 0 0;'><span><span>with wetlands. The criteria used are selected estimated soil properties that are </span></span></p><p style='margin:0 0 0 0;'><span><span>described in "Soil Taxonomy" (Soil Survey Staff, 1999) and "Keys to Soil Taxonomy" </span></span></p><p style='margin:0 0 0 0;'><span>(Soil Survey Staff, 2006) and in the "Soil Survey Manual" (Soil Survey Division Staff, 1993). </span></p><p style='margin:0 0 0 0;'><span /></p><p style='margin:0 0 0 0;'><span><span>If soils are wet enough for a long enough period of time to be considered hydric, </span></span></p><p style='margin:0 0 0 0;'><span><span>they should exhibit certain properties that can be easily observed in the field. </span></span></p><p style='margin:0 0 0 0;'><span><span>These visible properties are indicators of hydric soils. The indicators used to make </span></span></p><p style='margin:0 0 0 0;'><span><span>onsite determinations of hydric soils are specified in "Field Indicators of Hydric </span></span></p><p style='margin:0 0 11 0;'><span><span>Soils in the United States" (Hurt and Vasilas, 2006).</span></span></p></div></div></div>