Abstract

A New Hydro-Enforced, 1:24,000 Digital Elevation Model for Mississippi

Author(s): Steil, J. ;  Walker, S.

A new, 10 meter, statewide, hydro-enforced, digital elevation model [DEM] was recently developed by the Mississippi Automated Resource Information System [MARIS] in cooperation with the USGS to better support modeling efforts than the previous 30 meter DEM. The utility of the old 30m DEM was limited by scale, artifacts of processing, and substantial data exclusions such as the Tenn-Tom Waterway and significant migration of the Mississippi River. The new model was developed over a number of years beginning with Mylar separates of 7.5 minute quadrangles. Mylar separates were scanned, vectorized, and resulting lines tagged with elevation values and other attributes. As contour lines are not contiguous across individual quad maps, each contour was connected to the contour of the adjacent quad to create a continuous line for a seamless coverage. Carrying contours were added throughout the state to ensure proper hydrologic modeling. Digital Rater Graphics [DRG’s] were also available to provide clarification for incorrectly tagged elevation values especially at quad boundaries. The 2007 National Aerial Imagery Program [NAIP] 1 meter imagery was used to perform the inclusion and proper placement of the Tenn-Tom Waterway as it was not included in many of the original quadrangles. NAIP imagery was also the basis for correcting the placement of the Mississippi River which had migrated up to 5 miles from the position on the original 7.5 minute maps. Some corrective hydrologic changes were made to the 1:24,000 National Hydrologic Dataset [NHD] to provide more accurate modeling. Partially as a result of this project, MARIS has become the steward of the NHD for Mississippi. Preliminary geometric changes were made to the NHD to reflect changes in the landscape since the publication of the quad maps. These changes were most common in the Delta region and will be incorporated into the official NHD. Due to software limitations, each county was processed separately with a 400 meter buffer. The ESRI Topo-to-Raster command was used to generate each county DEM. Each County was checked by USGS at Rolla, MO. The final DEM’s are included as part of the official National Elevation Dataset [NED] and are available for download from USGS or MARIS www.maris.state.ms.us/HTM/DownloadData/DEM.html.







 

Technical Presentations

  • Delta Water Quality
  • Delta Water and Agriculture
  • Wetlands
  • Water Quality
  • Sediments
  • Non-Point
  • Management and Sustainability
  • Wood Treatment
  • Modeling
  • Soil and Water Treatment

Workshops

Responsible Site Design: Implementing Innovative Stormwater Management Strategies

The primary goal of the workshop is to create a dynamic learning experience that examines the role of stormwater management in the built environment. The workshop will focus on integrating ecologically sound water management approaches into site design. After the workshop, attendees will be familiar with the following concepts and technical issues:

  • Knowledge of the stormwater treatment chain
  • Knowledge of the impact of land use codes on stormwater management
  • Application of a design process that mitigates the effects of stormwater on-site
  • Knowledge of the relationship between land use codes and design for innovative stormwater management

Information

For information contact:
Jessie Schmidt
MWRRI
Box 9680
Mississippi State, MS 39762
662-325-3295
jschmidt@cfr.msstate.edu