Metadata: nrsfsnpy

nrsfsnpy

This page last updated: 11/18/2019
Metadata created using Minnesota Geographic Metadata Guidelines


Go to Section:
  1. Overview
  2. Data Quality
  3. Data Organization
  4. Coordinate System
  5. Attributes
  6. Distribution - Get Data
  7. Metadata Reference

Section 1: Overview

Originator:Minnesota Department of Natural Resources

Title: nrsfsnpy

Abstract: This dataset estimates the pollution sensitivity of near-surface materials from the transmission time of water through 3 feet of soil and 7 feet of surficial geology, to a depth of 10 feet from the land surface.

Purpose: Redwood County Groundwater Atlas, Part B

Time Period of Content Date:

Currentness Reference: Source material were obtained in 2016.

Progress: Complete

Maintenance and Update Frequency: None Planned

Spatial Extent of Data: Redwood County, Minnesota

Bounding Coordinates: -95.62
-94.85
44.7
44.19

Place Keywords: Redwood County, Minnesota

Theme Keywords: pollution sensitivity, near surface

Theme Keyword Thesaurus: None

Access Constraints: None

Use Constraints: Users may wish to verify critical information; sources include both the references here and information on file in the offices of the Minnesota Geological Survey and the Minnesota Department of Natural Resources. Every effort has been made to ensure the interpretation shown conforms to sound geologic and cartographic principles. This map should not be used to establish legal title, boundaries, or locations of improvements.

Contact Person Information: Holly Johnson, GIS Specialist
Minnesota Department of Natural Resources
500 Lafayette Rd
St. Paul, MN  55155-4025
Phone: 651-259-5693
Email: holly.je.johnson@state.mn.us

Browse Graphic: None available

Associated Data Sets: Redwood County Geologic Atlas, Part A, published by the Minnesota Geological Survey (MGS). More information and downloadable data for Part A available on the MGS site: http://www.mngs.umn.edu/county_atlas/countyatlas.htm

Minnesota Hydrogeology Atlas HG-02: http://www.dnr.state.mn.us/waters/programs/gw_section/mapping/platesum/mha_ps-ns.html

Section 2: Data Quality

Attribute Accuracy: 1:100,000

Logical Consistency: Data are topologically correct using ArcGIS 10.6

Completeness: Complete

Horizontal Positional Accuracy: File was snapped to statewide 30 meter LiDAR data.

Vertical Positional Accuracy: NA

Lineage: The pollution sensitivity of near-surface materials is an estimate of the time it takes for water to infiltrate the land surface to a depth of 10 feet. It is intended to estimate the time of travel through the unsaturated zone to reach the water table, which for the purposes of this method, is assumed to be 10 feet below land surface everywhere.

The matrix texture of a geological unit is determined from the fraction of the material that is less than 2 millimeters in size, and is described by the percent sand, silt, and clay of this fraction. The matrix texture is used as a proxy for estimating the transmission rate, as coarse-grained materials have transmission rates greater than fine-grained materials because of the larger and more connected pore spaces between the grains. The transmission rate is estimated with a two-layer approach using two primary inputs: NRCS data for the soil layer (0 to 3 feet) and the surficial geologic map for underlying geologic materials (3 to 10 feet). The published saturated hydraulic conductivity rates are converted to unsaturated rates. The transmission rate of the soil layer is derived from the Hydrologic Soil Group, which is a proxy for texture. Special conditions override this approach for regions where the regionally unique geology dominates.

Pollution sensitivity of near-surface materials was derived from the following datasets:
- NRCS soil survey tabular and spatial data, using the hydrologic soil groups for transmission rate determination. SSURGO was the primary source of soil data.
- Surficial geology coverage was delineated from the county surficial geology map from the MGS. The map units were joined with the surficial geology unit texture database created by MGS.

Transmission rates for the soil layer and the surficial geology layer are determined by correlating the hydrologic soil group and the matrix texture, respectively, with the transmission rates shown in Table 2 in HG-02: files.dnr.state.mn.us/waters/groundwater_section/mapping/mha/hg02_report.pdf.

The general approach used to create the maps is as follows: (A) GIS polygons from soil and surficial geologic units are converted to rasters with 30-meter cells, with their transmission rates as the cell value. (B) Conditional statements are used to calculate travel time given the availability of soil and surficial geology data at a specific location where soil and surficial geology raster cells are coincident.

The two-layer model was applied to large portions of the state. However, special conditions override this approach for regions where unique geological environments dominate: karst, bedrock at or near surface, north-central peatlands, and large areas of disturbed land. The delineation of karst is from GW-01 Minnesota Regions Prone to Surface Karst Feature Development. The bedrock at or near surface and the disturbed lands are from surficial geology maps. The north-central peatlands are delineated from the Ecological Land Type Associations of Minnesota. Not all of these conditions necessarily exist within the county.

Section 3: Spatial Data Organization (not used in this metadata)


Section 4: Coordinate System

Horizontal Coordinate Scheme: Universal Transverse Mercator

UTM Zone Number: 15

Horizontal Datum: NAD83

Horizontal Units: meters

Vertical Datum:

Vertical Units:

Depth Datum:

Depth Units:

Section 5: Attributes

Overview:

Detailed Citation:

Table Detail:
nrsfsnpy
Field NameValid ValuesDefinitionDefinition Source
RATINGenumeratedgeologic sensitivity rating of the near surface materials as defined by vertical travel time
nsHhigh: hours to a week
nsMmoderate: a week to weeks
nsLlow: weeks to months
nsVLvery low: months to a year
waternot rated
bedrockbedrock at or near surface

Section 6: Distribution

Publisher: Minnesota Department of Natural Resources, Ecological and Water Resources Division

Publication Date: 11/18/2019

Contact Person Information: Holly Johnson, GIS Specialist
Minnesota Department of Natural Resources
500 Lafayette Rd
St. Paul, MN  55155-4025
Phone: 651-259-5693
Email: holly.je.johnson@state.mn.us

Distributor's Data Set Identifier: nrsfspy

Distribution Liability: These data were prepared from publicly available information only. Every reasonable effort has been made to ensure the accuracy of the factual data on which these files are based. However, the Department of Natural Resources does not warrant the accuracy, completeness, or any implied uses of these data. Users may wish to verify critical information; sources include both the references here and information on file in the offices of the Department of Natural Resources.

Ordering Instructions: Download zip file of metadata and feature classes by clicking "I AGREE" below.

PDFs of the County Groundwater Atlas plates can be downloaded at: http://www.dnr.state.mn.us/waters/groundwater_section/mapping/status.html

Online Linkage: I AGREE to the notice in "Distribution Liability" above. Clicking to agree will either begin the download process, link to a service, or provide more instructions. See "Ordering Instructions" above for details.

Section 7: Metadata Reference

Metadata Date: 11/18/2019

Contact Person Information: Holly Johnson, GIS Specialist
Minnesota Department of Natural Resources
500 Lafayette Rd
St. Paul, MN  55155-4025
Phone: 651-259-5693
Email: holly.je.johnson@state.mn.us

Metadata Standard Name: Minnesota Geographic Metadata Guidelines

Metadata Standard Version: 1.2



This page last updated: 11/18/2019
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