Any available soil information concerning the area of interest should be gathered before the beginning of a
military engineering project. During operations, the actual soil conditions encountered should be noted in order to
update, verify, or modify the existing data bases and also to update intelligence estimates in cases where the new
information has an impact on current or future operations.
PART A - SOURCES OF INFORMATION
There are several sources from which soil information may be obtained, including field investigations, maps,
aerial photography, and soil reports. Written materials and maps may be acquired through various agencies, such
as the United States Geological Survey, the Defense Mapping Agency, the United States Soil Conservation
Service, the National Forest Service, and state geological agencies and private organizations. In addition, it is
sometimes necessary to use materials prepared by foreign governments or companies. The classification schemes
and accuracy of data vary from one source to another; therefore, many different sources should be used to achieve
maximum accuracy and completeness of the data base. If the information sources are questionable, the uncertain
reliability of the data should be noted. The collection of soil information is an ongoing process whereby the data
base is continually updated with more current and increasingly accurate data. Once a sufficient amount of data
has initially been collected, the analysis process begins with a critical review of the database materials on hand.
1. Field Investigations. The most accurate and reliable source of soil information, and consequently the most
desirable, is actual field investigation. Unfortunately, the amount of reconnaissance that can realistically be
completed is often insufficient to provide all the information needed. In fact, it is sometimes impossible to
sources of information must be consulted.
2. Maps. There are several different types of maps that can supply information concerning the unconsolidated
materials of an area, including soils, landform distribution, and geologic and topographic maps.
a. Soil Maps. Soil maps depict the geographic distribution of various types of unconsolidated surficial
materials. Where available, these types of maps generally provide excellent sources of information. However, it
should be noted that the majority of widely available soil maps are published by the United States Soil
Conservation Service, an agency primarily concerned with the agricultural characteristics and applications of
soils. Therefore, it may be necessary to interpret engineering classifications from such maps.
b. Landform Distribution Maps. Landform distribution maps depict the geographic distribution of various
landforms that, in turn, may indicate certain soil characteristics. For example, a region depicted as rugged,
mountainous terrain on a landform distribution map would likely contain stony, shallow soils, whereas soils
measuring several meters in thickness may be found in areas depicted as floodplains or stream terraces. Landform
distribution maps may even be used to estimate specific soil types and associated engineering properties. For
example, areas depicted as swamps or marshes usually contain highly organic soils that have