MAPPING AND REPRESENTING SOIL

INFORMATION AND DATA

Scales and complexities range Use/application determines appropriate scale

SOIL AND SCALE

Inventories, descriptions, evaluations, maps of soils in a county

Program established 1899 in USDA Farmers suitable crops and management practices

Now includes evaluation for other uses: construction, septic, farm planning, tax assessment, forest management, ecological research

Originally hard copy, paperback books Useful in the field

Now available as pdf files

COUNTY SOIL SURVEYS

Paper copy available from County NRCS office For counties that have been surveyed Free to public

PDF file available on NRCS MN web http://www.mn.nrcs.usda.gov

Surveys include:-general information about the county -descriptions of all the soil types in the county-tables of information on:

suitabiity, limitations, management for specific uses

COUNTY SOIL SURVEYS:

By digging a lot of holes! to observe profiles

Observing slopes, water tables, landscape, parent material, vegetation, crops, climate

Create a conceptual model of how soils were formed Use these models during mapping to PREDICT what kind of soil

will be present in a particular landscape

Sample some soils to determine laboratory and engineering characteristics

HOW ARE SURVEYS MADE?(Goal: map county soils)

Broad areas with soils, relief and drainage

Each unit represents a particular natural landscape

Useful for general land uses; not good for a farm or field or road or building

General map units are shown as: Soil- landscape block diagrams Written descriptions Color map in soil survey

GENERAL SOIL MAP UNITS(also called ASSOCIATIONS)

Aitkin County, Volume One (look at general description of county, climate tables, general map

unit descriptions and block diagrams) (look at General Soil Map)

AITKIN COUNTY EXAMPLE

“Map unit” Soils blend into one another; do not follow strict boundaries,

therefore a challenge to map Areas of one particular soil can hardly ever be mapped without including

other soils Map unit solves this issue by including similar soils

Named by the dominant soil in the unit Each map unit has a dominant soil and inclusions (other similar soils)

Example: p. 43 of Aitkin survey: #292 Alstad Loam (Map Unit)

85% Alstad 15% inclusions

DETAILED SOIL MAP UNITS

Unit of taxonomyAll major horizons in a series are similar

But they can differ in some characteristics, like stoniness, texture, wetness, etc.

These allowable differences are listed as Range of Characteristics after each series description

Each series gives its taxonomic class : “Fine-loamy mixed Glossaquic Eutroboralf”

We can find a detailed description of the Alstad Series Series descriptions are listed alphabetically

Example: Alstad series, Aitkin County (look for series description, range in characteristics, taxonomic class)

SERIES DESCRIPTIONS

Hierarchical categories“Fine-loamy mixed Glossaquic Eutroboralf”

OrderSuborderGreat groupSubgroupFamily

Series

AlfisolBoralfsEutroboralfsGlossaquic Eutroboralf“Fine-loamy mixed

Glossaquic Eutroboralf”

Alstad

Alstad Series:“Fine-loamy mixed Glossaquic Eutroboralf”

Fine-loamy

TAXONOMIC CLASS

Particle size

mixed

Mixture of clay minerals

superactive

High CEC

frigid

mean annualtemp <8°C;>6°C range

Note : Series are listed alphabetically, but map unit numbers are not in order, therefore need to consult Soil Legend to look up numbers from maps

“The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into segments that have similar use and management requirements…if intensive use of small areas is planned, onsite investigations is needed to define and locate the soils…”

Soil survey maps do not preclude field checking!!!

Soil series descriptionswww.soils.usda.gov/technical/classification/osd

Soils Data Mart www.soildatamart.nrcs.usda.gov

OTHER USEFUL LINKS ON MN NRCS

www.soils.usda.gov

Soil TaxonomyKeys to Soil TaxonomyGlossary

PUBLICATIONS

Spatially referenced GIS-compatible format

Geographic Information Systems

Data sets identify soils with similar characteristics and tables describe attributes (characteristics) of each delineated soil type

STATSGO SSURGO

GIS SOIL DATA

State Soil Geographic database

More generalized than SSURGO 1;250,000

For land use planning over large areas

Need GIS or Web Soil Survey

STATSGO

Soil Survey Geographic database “SSURGO-certified”

National cartographic standards

More detail than STATSGO 1:12,000 to 1:63,360

Landowners and county-level planningNeed GIS or Web Soil Survey

Current state of mapping in MN

SSURGO

Site-Level Management: Detailed applications:

Precision agriculture, UMD farm recommendations, septic mound location On-site investigation by soils person to augment info in county survey (if one

is available) Up to 1: 5000

Local Planning: Residential and commercial development, transportation,

recreation, open space and natural areas County soil surveys: 1:20,000

Generalized characterization of Landscape: Broad management and ecological research Statewide data sets

DATA USES AND SCALE

Interface for users who do not have/use/know GIS; can access SSURGO data.

Web Soil Survey

WEB SOIL SURVEY

Include past hydrology in the MN/Model.

SAMPLE PROJECT USING SSURGO DATA:

Mn/Model 2002

Archaeological predictive model used by Mn DOT to avoid destroying or disturbing archaeological sites during road construction projects.

GIS statistical model of High, Medium, Low likelihood

Important input to model is landscape

Lacked past hydrology

Soil CriteriaMn/DOT formatted soil datasetMap Unit ComponentsTaxonomyGreat Groups (18)Histosols, Aquic Suborders, UdifluventsBlue Earth example, Hennepin exampleHydric RatingDrainage Classes

existing lakes, streams, and wetlands

county SSURGO soils data

30m elevation data / geomorphology

General Land Office survey maps

Existing GIS data used to derive historic water features

Conceptual Model to Create Historic

Water Features layer for Mn/Model

Phase 4.

GLO wetlands

Selected natural palustrine,

Lacustrine featuresAnd areas derived

from RDWI

NWI wetlands

4. NWI natural feature

selection plus RDWI

GLO lakes

Potential HistoricLake / Wetlandareas derived

from soil polygons

RDWI wetlands

MN DNRGeomorphology

Potential historicriverinefeatures

Mn/DOT soilsDerived from

SSURGO

MN DNRStreams

Identify fluvialfeatures

Identify perennialfeatures

Landform Sediment Assemblages

All historic water features

Identify riverinefeatures

5. Combine all potential

historic water

features

2. GLO lakes and wetlandsCorresponden

ce

1. select great groups and

eliminate_less_3acres

Identify riverinefeatures

3. Identify historic riverine features

Select great groupsfor riverine

features

Potential historiclake / wetland

areas with source field populated

Use if GLO delineations are not available

only if available

Input GIS dataset

Tool output dataset

Final model output dataset

Tool in ModelBuilder

Identification of Historic Lake and Wetland Features

Select Great Groups meeting hydric criteriaFilter Hydric = “P” and not Drainage = “VP” or “P”Aggregate neighboring polygonsDelete areas < 3 acresDissolve soil polygons of same Landform togetherExample of Tool 1 output in Hennepin Counties with GLO surveyed features Example of Tool 1 output in Hennepin County with HCD Wetland Inventory

Figure 6. Historic features illustrating Great Group selection in Blue Earth County

Figure 7. Historic features illustrating Great Group selection in Hennepin County

Figure 8. Example of Tool 1 output in Hennepin Counties with GLO surveyed features

Figure 9. Example of Tool 1 output in Hennepin Counties with HCD Wetland Inventory

Identify historic riverine features tool in ArcGIS ModelBuilder Select Hydric Great GroupsSubset Great Groups that intersect Fluvial Geomorphology (set 1)Select Riverine Features from NWI (set 2)Combine Set 1, Set 2, and Set 3 for Historic Riverine Features

Historic riverine features and associated data in Blue Earth County

Natural Features Selection Plus RDWI Tool in ArcGIS ModelBuilderEliminate artificial wetlands from NWI (Wreg = K, artificial; Spec_mod1 = b [beaver], h [impounded], or x [excavated])Select NWI that corresponds with RDWI, populate RDWI field = ‘y’Combine RDWI and NWI features

Combine all potential historic water features

Compare to General Land Office data?

Other studies in other counties (Hennepin)

Demonstration of SSURGO for use in GIS

http://soildatamart.nrcs.usda.gov/

http://www.lmic.state.mn.us/chouse/soil.html

Downloading dataImporting ssurgo into templateShapefilesTablesLinking and Joining Tables