Environmental Engineering Reference
In-Depth Information
Chapter 4
Hydric Soil Identification Techniques
Lenore M. Vasilas and Bruce L. Vasilas
Abstract Conceptually, hydric soils are soils that formed under hydrologic
conditions associated with wetlands. Identification of soils as “hydric” is critical to
the identification and protection of wetlands. Conditions of saturation and anaerobi-
osis associated with wetland hydrology create morphological characteristics in soils
that can be used to distinguish them from non-hydric (upland) soils. These distinc-
tive morphological characteristics have been used to develop “indicators” to facili-
tate the rapid identification of hydric soils in the field without relying on chemical
assays or long term monitoring. An understanding of how soils form and the soil
properties related to hydric soil morphologies such as soil color and texture are
needed to field identify indicators of hydric soils. This chapter emphasizes the proper
application of field indicators of hydric soils, the process of describing soil mor-
phology inherent to the use of hydric soil indicators, and approaches to address soils
suspected to be hydric but do not meet a field indicator.
4.1
Introduction
To fully understand the material in this chapter it should be accompanied by
Field
Indicators of Hydric Soils in the United States
(Version 7.0) (USDA, NRCS
2010a
)
and subsequent errata, the
Army Corps of Engineers Wetlands Delineation Manual
(Environmental Laboratory
1987
) and approved Regional Supplements (U.S. Army,
COE
2012
), and the
Munsell Book of Color
(available fromMunsell Color Company,
Inc. Baltimore MD).
