||The examples and perspective in this article may not represent a worldwide view of the subject. (December 2010)|
Soil survey, or soil mapping, is the process of classifying soil types and other soil properties in a given area and geo-encoding such information. It applies the principles of soil science, and draws heavily from geomorphology, theories of soil formation, physical geography, and analysis of vegetation and land use patterns. Primary data for the soil survey are acquired by field sampling and by remote sensing. Remote sensing principally uses aerial photography, but LiDAR and other digital techniques are steadily gaining in popularity. In the past, a soil scientist would take hard-copies of aerial photography, topo-sheets, and mapping keys into the field with them. Today, a growing number of soil scientists bring a ruggedized tablet computer and GPS into the field with them. The tablet may be loaded with digital aerial photos, LiDAR, topography, soil geodatabases, mapping keys, and more.
The term soil survey may also be used as a noun to describe the published results. In the United States, these surveys were once published in book form for individual counties by the National Cooperative Soil Survey. Today, soil surveys are no longer published in book form; they are published to the web and accessed on NRCS Web Soil Survey where a person can create a custom soil survey. This allows for rapid flow of the latest soil information to the user. In the past it could take years to publish a paper soil survey. Today it takes only moments for changes to go live to the public. Also, the most current soil survey data is made available at NRCS Soil Data Mart for high end GIS users such as professional consulting companies and universities.
The information in a soil survey can be used by farmers and ranchers to help determine whether a particular soil type is suited for crops or livestock and what type of soil management might be required. An architect or engineer might use the engineering properties of a soil to determine whether it is suitable for a certain type of construction. A homeowner may even use the information for maintaining or constructing their garden, yard, or home.
Soil survey components
Typical information in a published county soil survey includes the following:
- a brief overview of the county's geography
- a general soil map with a brief description of each of the major soil types found in the county along with their characteristics
- detailed aerial photographs with specific soil types outlined and indexed
- photographs of some of the typical soils found in the area
- tables containing general information about the various soils such as total area, comparisons of production of typical crops and common range plants. They also include extensive interpretations for Land use planning such as limitations for dwellings with and without basements, shallow excavations, small commercial buildings, septic tank adsorptions, suitability for development, construction, and water management.
- tables containing specific physical, chemical, and engineering properties such as soil depth, soil texture, particle size and distribution, plasticity, permeability, available water capacity, shrink-swell potential, corrosion properties, and erodibility.
- A Compendium of On-Line Soil Survey Information
- NRCS Web Soil Survey Inventory of the soil resource across the U.S.
- NRCS Soil Data Mart
- NRCS Helping People Understand Soils
- California Online Soil Survey
- Texas Soil Surveys, hosted by the Portal to Texas History
- Soil Maps of the world European Digital Archive on the Soil Maps of the world
- Historical Soil Surveys of South Carolina at the University of South Carolina Library's Digital Collections Page