Abstract: The Lower Portneuf River Valley Aquifer (LPRVA) boundary was created by using the location (Idaho East,
State Plane, NAD 83) and the mean-sea-level (MSL)of 41 points and contour lines derived from a 30-m DEM at 1342-m, 1363-m,
1374-m, and 1377-m contour intervals. The boundary was also created by using a computed hillshade (azimuth=300,
altitude = 30) of the 30-m DEM and a SSURGO soil map.
The 41 points are control points which were taken with a Trimble ProXR GPS unit having submeter horizontal accuracy
and meter vertical accuracy. The southeastern aquifer boundary was determined by GPSing control points along the southwestern
boundary of the LDS Farm on the NE side of Bannock Highway where the farm land is planer.
The northeastern side of the valley is higher than the southwestern side due to the Portneuf Basalt. Thus, the aquifer boundary
was defined by the northeastern boundary of the Pocatello silt loam located NE of the Portneuf Basalt.
The valley rises in elevation southeastward towards the Portneuf Gap and is the reason why 4 contour lines were used to
define the aquifer boundary. The elevation of some of the control points were used to determine the contour intervals.
The aquifer boundary was drawn between the control points by using the contour lines, 30-m DEM computed hillshade topography,
and the SSURGO soil map.
The best control points are in the Portneuf Gap between Bannock Highway and the LDS Farm land between the Pocatello City
Cemetary and the southeast end of Red Hill, and a point located along Stockman Road.
Some of the control points were used to estimate the aquifer boundary passing beneath alluvial fans such as the one formed
at the mouth of Fort Hall Canyon.
Theme Keyword: Hydrology
Place Keyword: Bannock
Bounding Coordinates: (555000
471440) to (606534
409762) Idaho East
State Plane
NAD 83
Purpose: Delineation of the LPRV aquifer
Supplemental Information: The data does not represent legally defined boundaries
Native data set environment: ArcView 3.1 on a WinNT 4.0 platform
Cross reference: RGI data release 4
Time period of content:
Calendar Date: 8/4/99
Currentness reference: Data of metadata
Progress: Partial
Maintenance and update frequency: As needed
Data set credit: Idaho State University GIS Training and Research Center (John Kaser)
II. Projection Information:
Map projection name: Transverse Mercator (State Plane Coordinate Sytem)
III. Spatial Data Organization:
Indirect spatial reference: Lower Portneuf watershed and Fort Hall Indian Reservation
IV. Contact Information:
Contact person (primary): John Kaser
V. Data dictionary:
Entity and attribute overview: Arc attribute table. Contains Arc (line) generated fields.
VI. Source information:
Source citation:
VII. Processing steps:
Process description: GPS'd control points, contour lines, computed hillshade, and a SSURGO
soil map were brought into and overlain in an ArcView 3.1 project. A line theme was then created
through heads-up digitizing using the layers listed above. The line theme was then brought into
ArcInfo, where it was built and cleaned as a line coverage.
VIII. Data quality:
Horizontal positional accuracy value: Varies
Horizontal datum name: NAD 83
Ellipsoid name: GRS 80
Altitude datum name: National Geodetic Vertical Datum of 1929
Planar distance units: Feet
Altitude distance units: meters
Longitude of central meridian: -112 10 00
Latitude of projection origin: 41 40 00
False northing: 0
False easting: 200,000 meters
Coordinate precision: single
Indirect spatial reference: Lower Portneuf watershed and Fort Hall Indian Reservation
Direct spatial reference: Vector
SDTS Point and vector object type: Complete chain ( arc or line)
Contact position: GIS Specialist
Contact organization (primary): Idaho State University - GIS Training and Research Center
Contact address:
Address: Campus Box 8130
City: Pocatello
State: ID
Postal Code: 83209-8130
Contact voice telephone: 208.236.3606
Contact electronic mail address: kasejohn@isu.edu
Hours of service: 8 a.m. - 5 p.m. MST Mon- Fri
Attribute elements:
Attribute (field) no.: 1
Attribute label: Aquiferbou
Attribute definition: Aquifer Name
Attribute definition source: Create by John Kaser to identify aquifer
Attribute domain: LPRV Aquifer
Attribute format type: Character
Attribute format length: 12
Attribute measurement resolution: Not applicable
Attribute units of measure: Not applicable
Attribute value accuracy: Not applicable
Attribute value accuracy explanation: Name designation for aquifer
Attribute measurement frequency: Unknown
Title: 30-m DEM
SSURGO soil map
Originator: The 30-m DEM and the SSURGO soil map were provided
by the ISU Geology Department GIS laboratory
Publication date: unknown
Source contribution: A computed hillshade coverage (azimuth = 300, altitude = 50) and 4 contour lines created from
the 30-m DEM and the SSURGO soil map were used to delineate the LPRV aquifer boundary through heads-up digitizing.
Source scale denominator: 1:24000
Type of source media: Digital
Process date: 8/1/99
Process time: 8:00 AM
Process contact: John Kaser
ISU GIS center
Horizontal positional accuracy explanation: The accuracy of were the aquifer truely lies in unknown. The control
points that were used are of submeter accuracy. The aquifer boundary was drawn by using available information.
Vertical positional accuracy statement: varies
Vertical positional accuracy explanation: Accuracy depends on the degital layer being used, i.e. 30-m DEM vs 90-m DEM.
For DEMs the vertical is usually +/- 10-m or +/- 15-m. The positional accuracy of the aquifer boundary that coincide with the
control points will be +/- 2-m.
Logical consistency report: Data set is topologically structured arc data.
Completeness report: Complete pending review