Assessing Soil Characteristics and Limitations along Pipeline rights-of-Way using GIS Spatial and Attribute Data integration and Management

Assessing Soil Characteristics and Limitations along Pipeline rights-of-Way using GIS Spatial and Attribute Data integration and Management

Jim Arndt, Ph.D., Senior Natural Resource Specialist

Joe Flannery, GIS Manager

Topsoil Segregation

Stony/Rocky

Special Soil Handling

Soil Assessment and Visualization: GIS and Database

Visualization

• Soil characteristics are particularly important in pipeline construction

• FERC Resource reports: RR6 and RR7

• EIS preparation• Identification of construction-

related issues

Old Surveys, New Surveys, Better SurveysOld Surveys, New Surveys, Better Surveys

Old Surveys• Dated• Inconsistent

Format• Hard to use• Agricultural

emphasis• Soil Professional

emphasis

“New” Surveys• Current• Consistent

format• User friendly• Broader

audience (Not just Agriculture)

• Difficult for large projects

GIS Surveys (SSURGO2)• Easier to use• Cheap (once made)• Easily distributed• Availability close to 100%• Engineering-related data • Many engineering

interpretations

NRCS SSURGO2 Database is Available to Anyone with a Computer!

Download in Access format from Web.

Canned interpretations.

A user-friendly forms input structure.

One database – All counties for specific project

Use specific queries easily developed

Soil Properties and Interpretations DatabaseSoil Properties and Interpretations Database

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

Components of a SSURGO2 Soil Survey: Soil AttributesComponents of a SSURGO2 Soil Survey: Soil Attributes

Access template Generic, but can be specific

to state Form populates tables

automatically Front-end GUI Query Format

User-friendly front end (access database)

Database: Tables Physical and Chemical

Properties Interpretations User defined queries

Access template Generic, but can be specific

to state Form populates tables

automatically Front-end GUI Query Format

User-friendly front end (access database)

Database: Tables Physical and Chemical

Properties Interpretations User defined queries

The SSURGO2 Database in Microsoft Access

Map unit and legend tables connect to spatial map data

Component tables provide physical and chemical characteristics of the whole soil, and interpretations for various uses.

Layer Tables provide physical and chemical characteristics for each soil layer.

Tables are linked in the database by Common (key) Fields.

One to Many relationships

Map unit and legend tables connect to spatial map data

Component tables provide physical and chemical characteristics of the whole soil, and interpretations for various uses.

Layer Tables provide physical and chemical characteristics for each soil layer.

Tables are linked in the database by Common (key) Fields.

One to Many relationships

Less SpecificSoil Survey Area

Map Units

More SpecificComponent SeriesSoil Profile Layers

Key Field Links

1 to ∞Relationship

Queries Reduce Data and Combine Specific Properties and Limitations

Selected fields

Tables or queries

Expression BuilderConditional statementsMathematical statements

Example Droughty Soils

“Texture is coarser than sandy loam and drainage class is drier than moderately well”

Complex queries can be developed that incorporate mathematical and conditional statements

Components of a SSURGO2 Soil Survey (2) Components of a SSURGO2 Soil Survey (2)

Maps

Soil polygons in ESRI Arcview/Arcmap format

Attributed with labels indicating soil survey area and map unit

Digital Soil Map Unit polygons go through extensive QA/QC

Relates to polygon line placement, not soil boundaries

Maps

Soil polygons in ESRI Arcview/Arcmap format

Attributed with labels indicating soil survey area and map unit

Digital Soil Map Unit polygons go through extensive QA/QC

Relates to polygon line placement, not soil boundaries

Basemaps in GIS – can be very high resolution (1-foot pixel) Use-specific basemaps (e.g. geology, hydrology, USGS

quadrangles)

Association is block diagram. Shows what soils can be expected.

Soil map Units (dotted lines) show where specific soils are consistently found.

CONSOCIATION. Some soils map units consist of one dominant soil type. Easy to assess.

COMPLEX. Two or more soils to mixed up to map separately

Association is block diagram. Shows what soils can be expected.

Soil map Units (dotted lines) show where specific soils are consistently found.

CONSOCIATION. Some soils map units consist of one dominant soil type. Easy to assess.

COMPLEX. Two or more soils to mixed up to map separately

Inclusions. Minor soils found in soil map units. Cannot be incorporated into assessment as data in the database is not provided for inclusions.

RESULT. Minor amounts of different soils can be found in any soil map unit. A TOOL: NO GUARANTEES OF PURITY.

Waukegan/Kasota

Hayden

Dickman

Sparta

Waukegan/Kasota

Estherville

Biscay

Dickman

Sparta

Minneiska

Hayden(storden)

Soil AssociationsSoil Map UnitsConsociations

Complexes

Important Soil Limitations Covered

Whole Map Unit (One or more dominant soils) Prime Farmland Highly Erodible Land

Whole Component Soil Series (One Soil) Bedrock: Presence and hardness (soft; rippable, hard; blast or other) Slope Class: 0-5, 5-8, 8-15, 15-30, >30 Hydric Soils: Component of wetland, if drained possibility of draintile,

generally high water table in any event Water Erodible, Wind Erodible, Droughty. NRCS classifications, affects

stormwater management, reclamation Depth and persistence of the water table. Ponded, flooded, saturated

Soil Profile Layers (Up to seven horizons, generally to five feet) Topsoil depth: 0-6, 6-12, 12-18, >18, Deep Peat, Shallow Peat. Surface Stones: >5% on top soil horizon. Profile Stones: >5% average in profile (51 inches). Gradation of Sandy Soils – Wet and Dry. Poorly, moderately, and well graded based on

Texture classification (USDA, AASHTO, UNIFIED) Chemistry: pH, saline soils, sodic soils Texture: Triple lift candidates, contrasting sub-soils

Whole Map Unit (One or more dominant soils) Prime Farmland Highly Erodible Land

Whole Component Soil Series (One Soil) Bedrock: Presence and hardness (soft; rippable, hard; blast or other) Slope Class: 0-5, 5-8, 8-15, 15-30, >30 Hydric Soils: Component of wetland, if drained possibility of draintile,

generally high water table in any event Water Erodible, Wind Erodible, Droughty. NRCS classifications, affects

stormwater management, reclamation Depth and persistence of the water table. Ponded, flooded, saturated

Soil Profile Layers (Up to seven horizons, generally to five feet) Topsoil depth: 0-6, 6-12, 12-18, >18, Deep Peat, Shallow Peat. Surface Stones: >5% on top soil horizon. Profile Stones: >5% average in profile (51 inches). Gradation of Sandy Soils – Wet and Dry. Poorly, moderately, and well graded based on

Texture classification (USDA, AASHTO, UNIFIED) Chemistry: pH, saline soils, sodic soils Texture: Triple lift candidates, contrasting sub-soils

Soil Consociation (A) • 92% Soil 1• 8% Soil 2• 92/92 = 1.0 Decimal

Fraction Dominant Soil

(1) 92%

(2) 8%

(1) 55%(2) 40%

(3) 5%

Soil Complex or Undifferentiated (B)

• 55% Soil 1• 40% Soil 2• 5% Soil 3• 55/(55+40) = 0.58

Decimal Fraction Soil 1• 40/(55+40) = 0.42

Decimal Fraction Soil 2• Inclusions removed

Normalizing Map Unit Component Composition To Remove Inclusions

Determining Crossing Lengths for Map Unit Components In Arcmap GIS

Determining Crossing Lengths for Map Unit Components In Arcmap GIS

MP 403

0.116 Miles0.385 Miles

Soil map Unit

FMEAS TMEAS Crossed

A 402.230 402.336 0.116

B 402.336 402.721 0.385

The proposed route feature is first prepared in the GIS by calibrating it with real-world length or to a predefined milepost/stationing system.

Feature crossing tables are then created by using the “Locate Features Along Route” tool in the GIS. The tool computes the route and measure information at the geometric intersection of polygon data and route data.

402.230

402.336 402.336

402.721

Soil Consociation (A): 0.116 * 1.00 Soil 1 = 0.116 Soil Complex or Undifferentiated (B): 0.385 * 0.58 Soil 1 = 0.223

0.385 * 0.42 Soil 2 = 0.162

Determining Crossing lengths for Map Unit Components Determining Crossing lengths for Map Unit Components

MP 403

402.230

402.336 402.336

402.721

0.116 Miles0.385 Miles

Soil Map Unit

FMEAS TMEAS Crossed

A 402.230 402.336 0.116

BSoil 1Soil 2

402.336 402.721 0.3850.2230.162

In GIS soil complexes consist of two overlapping polygons with hatching indicating the level of the limitation.

Consolidation Queries Accumulate Data From Property Specific Queries

The consolidation query builds a table of soil limitations by milepost for direct use of data or summarized as pivot tables directly in Access or Excel

Milepost Query

Selected fields

Ins, Outs, and Seeing What You’ve Got (1)Ins, Outs, and Seeing What You’ve Got (1)

GIS group provides crossing tables with upstream and downstream mileposts for all soil map units crossed. ~5000+ on 300+ mile projects

The database is used to separate map units into component soil series and calculate map unit composition excluding inclusions.

The database then calculates soil component crossing length for each map unit.

GIS group provides crossing tables with upstream and downstream mileposts for all soil map units crossed. ~5000+ on 300+ mile projects

The database is used to separate map units into component soil series and calculate map unit composition excluding inclusions.

The database then calculates soil component crossing length for each map unit.

Ins, Outs, and Seeing What You’ve Got (2)Ins, Outs, and Seeing What You’ve Got (2)

Database queries by NRG Soil Scientist relates soil limitations for specific soils by Milepost increment

Topsoil Depth, Slope, wet, organic, rocky, bedrock, caving slump hazards

Pivot Tables Summarize Data by County, Spread

Used in Resource reports, pre-filing applications, project bid documents

Detailed tables used by contractors to identify areas of particular limitations.

Used in Resource reports, pre-filing applications, project bid documents

Detailed tables used by contractors to identify areas of particular limitations.

Ins, Outs, and Seeing What You’ve Got (3)Ins, Outs, and Seeing What You’ve Got (3)

Soil limitations visualized in GIS: Spatially correct.

Soil Boundary Topsoil Depth Sandy Grade Wet Sandy Hydric

Soil Limitations visualized in GIS with limitation classes.

• Topsoil depth affects construction width, storage needs, regulatory compliance.• Sandy soil affects constructability.• Wet and Sandy soils subject to slumping, affects construction width needs.• Hydric soil affects construction techniques, regulatory compliance.

Visualizing Properties for Soil Complexes Visualizing Properties for Soil Complexes

Consociations (one dominant soil) are separated in the database into one layer Complexes are separated out as one layer for each soil component and merged Hatches with transparent backgrounds identify overlapping polygons with varying soil

properties

Consociations (one dominant soil) are separated in the database into one layer Complexes are separated out as one layer for each soil component and merged Hatches with transparent backgrounds identify overlapping polygons with varying soil

properties

Consociation: One Dominant Soil, >12-18 inch topsoil,

representative value 17 inches

Complex: Three dominant soils.

Soil 1: >18 inches

Soil 2: Shallow Organic

Soil 3: Deep Organic

Using the “Identify” tool in Arcmap will bring up information on component percentages for each soil. Tables provide all of the values.

Ins, Outs, and Seeing What You’ve Got (4)Ins, Outs, and Seeing What You’ve Got (4)

ID tool in Arcmap provides all data for a single map unit in one view.BUT, how do you use this in the field?

Use-specific Soil Interpretation Alignment SheetsMapbook procedure: Exactly Same Views

Soil map units, 5-foot contours, tract numbers

Topsoil depth increment, SSURGO2-representative depth

Compaction-prone soils

Any combination of soil limitations can be

depicted

Caveats System is a planning tool to better prepare for

construction.

Data only as good as the soil survey. (note scale is 1:24,000, best we have).

Inclusions not accounted for. Inclusions are small amounts of dissimilar soils not mapped within the unit. Generally account for 5-10%, frequently hydric.Small amounts of wet areas and soils with contrasting properties are possible, but

should not be present in significant amounts.

Will not substitute for field assessments.

Soils map unit complexes are difficult to work with. Complexes consist of two to three soils not specifically mapped out within the map unit. Data provide evaluation of the amount of each soil type within map unit, but

give no indication of where the soils will be found.

System is a planning tool to better prepare for construction.

Data only as good as the soil survey. (note scale is 1:24,000, best we have).

Inclusions not accounted for. Inclusions are small amounts of dissimilar soils not mapped within the unit. Generally account for 5-10%, frequently hydric.Small amounts of wet areas and soils with contrasting properties are possible, but

should not be present in significant amounts.

Will not substitute for field assessments.

Soils map unit complexes are difficult to work with. Complexes consist of two to three soils not specifically mapped out within the map unit. Data provide evaluation of the amount of each soil type within map unit, but

give no indication of where the soils will be found.

DemonstrationDemonstration

Pivot Table Summaries

Access Front End

RelationshipsTables

Queries

Questions