Nitrate Risk to the Water Table Aquifer

Metadata also available as

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator:
Minnesota Department of Health - Environmental Health - Source Water Proctection
Title: Nitrate Risk to the Water Table Aquifer
Geospatial_Data_Presentation_Form: raster digital data
Description:
Abstract:
Nitrate-nitrogen (nitrate) risk ranking maps have been constructed for the water table aquifer beneath eleven southeastern Minnesota counties, the seven-county Twin City Metropolitan Area, and twelve additional counties throughout central and south-central Minnesota. Additional counties will be mapped as base data becomes available. Nitrate loading to the subsurface is estimated by reclassification of land use data (ranging from 1 point for relatively low to 5 points for relatively high estimated nitrate loading). Hydrogeologic sensitivity for the water table aquifer is ranked from low (1 point) to very high (4 points) based upon the permeability of geologic materials (surficial geology, soil parent material type and bedrock type), land slope, and the relationship between depth to water and depth to bedrock. Adding the estimated nitrate loading raster to the hydrogeologic sensitivity raster simulates nitrate release to the water table, and produces the nitrate risk map for the water aquifer. The final point score can fall within nitrate risk ranges classed on the final map as low (up to 4 points), moderate (5 to 6 points), or high (7 to 9 points). The results are checked by comparison to available nitrate chemical data collected from wells within the county being mapped.
Purpose:
Minnesota Department of Health (MDH) Source Water Protection initially developed county-scale nitrate risk maps in 2007 for nine southeastern Minnesota counties to assist with state and local water quality planning efforts and support a nitrate occurrence study (Southeast Minnesota Water Resources Board, 2009). The mapping effort has now expanded to include 30 counties. The nitrate risk ranking map is at an approximate scale of 1:100,000 and identifies areas where the water table aquifer is classified as having relatively high, moderate, or low sensitivity to contaminant sources originating at the ground surface, including nitrate. Such maps are useful for wellhead protection and other water planning efforts.
Status:
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -96.502240
East_Bounding_Coordinate: -90.435454
North_Bounding_Coordinate: 47.263585
South_Bounding_Coordinate: 43.452660
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: Nitrate Risk Mapping
Theme_Keyword: Nitrate Probability Mapping
Theme_Keyword: Nitrate Probability
Access_Constraints: None
Use_Constraints:
The maps are designed to be used at a scale of approximately 1:100,000 (county-scale). Map accuracy at larger scales (more detail or smaller area) cannot be verified due to the scale limitations on the base data used to generate the maps.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Minnesota Department of Health
Contact_Person: James Lundy
Contact_Position: Hydrologist Supervisor
Contact_Address:
Address_Type: physical
Address: 625 Robert Street North
City: Saint Paul
State_or_Province: Minnesota
Postal_Code: 55164-0975
Country: US
Contact_Voice_Telephone: 651-201-4649
Contact_Electronic_Mail_Address: james.lundy@state.mn.us
Data_Set_Credit:
Base data from National Agricultural Statistics Service, various county soil atlases, Minnesota Geological Survey's County Well Index, and MDH Environmental Health Division, Drinking Water Protection Section, Source Water Protection Unit. Final datasets prepared by MDH Source Water Protection Unit.
Native_Data_Set_Environment: Version 6.2 (Build 9200) ; Esri ArcGIS 10.2.2.3552

Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Grid Cell

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Map_Projection:
Map_Projection_Name: NAD 1983 UTM Zone 15N
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.9996
Longitude_of_Central_Meridian: -93.0
Latitude_of_Projection_Origin: 0.0
False_Easting: 500000.0
False_Northing: 0.0
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.000000002220024164500956
Ordinate_Resolution: 0.000000002220024164500956
Planar_Distance_Units: meter
Geodetic_Model:
Horizontal_Datum_Name: D North American 1983
Ellipsoid_Name: GRS 1980
Semi-major_Axis: 6378137.0
Denominator_of_Flattening_Ratio: 298.257222101

Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: SWP.SDE_VAT_41
Attribute:
Attribute_Label: OBJECTID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: Esri
Attribute_Domain_Values:
Unrepresentable_Domain:
Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: VALUE
Attribute_Definition:
The VALUE field numerically classifies the risk of nitrate entering the water table aquifer as 1 (low), 2 (moderate), 3 (high), or 4 (not evaluated).
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 1
Enumerated_Domain_Value_Definition: Low risk of nitrate entering the water table
Enumerated_Domain_Value_Definition_Source: Minnesota Department of Health
Enumerated_Domain:
Enumerated_Domain_Value: 2
Enumerated_Domain_Value_Definition: Moderate risk of nitrate entering the water table
Enumerated_Domain_Value_Definition_Source: Minnesota Department of Health
Enumerated_Domain:
Enumerated_Domain_Value: 3
Enumerated_Domain_Value_Definition: High risk of nitrate entering the water table
Enumerated_Domain_Value_Definition_Source: Minnesota Department of Health
Enumerated_Domain:
Enumerated_Domain_Value: 4
Enumerated_Domain_Value_Definition:
Not Evaluated. Insufficient information to evaluate for nitrate risk entering the water table
Enumerated_Domain_Value_Definition_Source: Minnesota Department of Health
Attribute:
Attribute_Label: COUNT
Attribute:
Attribute_Label: RISK
Attribute_Definition:
The RISK field classifies the risk of nitrate entering the water table based on the VALUE field, and can be Low, Moderate, High, or Not Evaluated.
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Low
Enumerated_Domain_Value_Definition: Low risk of nitrate entering the water table
Enumerated_Domain_Value_Definition_Source: Minnesota Department of Health
Enumerated_Domain:
Enumerated_Domain_Value: Medium
Enumerated_Domain_Value_Definition: Medium risk of nitrate entering the water table
Enumerated_Domain_Value_Definition_Source: Minnesota Department of Health
Enumerated_Domain:
Enumerated_Domain_Value: High
Enumerated_Domain_Value_Definition: High risk of nitrate entering the water table
Enumerated_Domain_Value_Definition_Source: Minnesota Department of Health
Enumerated_Domain:
Enumerated_Domain_Value: Not Evaluated
Enumerated_Domain_Value_Definition:
Insufficient information to evaluate for nitrate risk entering the water table
Enumerated_Domain_Value_Definition_Source: Minnesota Department of Health

Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
Minnesota Department of Health - Environmental Health - Source Water Proctection
Distribution_Liability: See access and use constraints information.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: <http://www.health.state.mn.us/divs/eh/water/swp/maps/index.htm>

Metadata_Reference_Information:
Metadata_Date: 20160222
Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time

Generated by mp version 2.9.12 on Mon Feb 22 10:44:37 2016