Development of Watershed and Sub-Watershed Boundaries

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					       Action Plan for the Development of 
        Watershed and Sub-Watershed 
          Boundaries for northwestern 
                  Mississippi :
                        Delineating in Problematic Areas
                 Claire E. Rose, K. Van Wilson, Richard A. Rebich
                                U.S. Geological Survey 
                                  Mississippi Water Science Center
                                          308 S. Airport Rd.
                                         Jackson, MS 39208
                                      in cooperation with 
                 Mississippi Department of Environmental Quality
U.S. Department of the Interior
U.S. Geological Survey
Background and Issues
Acquisition of LiDAR enables delineation of 
subtle topographic features




Philipp, MS 7.5-minute
topographic map, USGS 1981   LiDAR imagery, US ACE 2009
Purpose of Study
§ To develop sub-
  watershed boundaries for 
  watersheds in northwest 
  Mississippi. 
§ Complete the WBD for the 
  state of Mississippi to the 
  sub-watershed level.
§ Watershed and 
  ecosystem health 
  restoration depend on 
  completed sub-watershed 
  boundary dataset.
Map of Current 
delineation to sub-
watershed level
(all are in 
Mississippi Delta 
region)
37:  Number of 10-digit HUC 
watersheds in Northwest MS that 
need to be delineated down to the 12-
digit HUC sub-watershed boundaries.
~185:  Approximate number of12-
digit HUC sub-watershed boundaries 
that would be developed for NW MS
Flowchart of Data 
Objectives
Errors in the 
Yazoo River 
Basin Phase 1 
LiDAR
Dataset
          Explanation of LiDAR Errors

 USGS NGTOC: Responsible for reviewing
  LiDAR data before approval for inclusion in
  NED.
 Goal of QA/QC: Assure data are sufficient
  quality for scientific analysis.
 Errors, anomalies and other issues were
  documented in the LiDAR Data from the
  Yazoo River Basin (Phase 1).
 147 Errors were found including:
     Floating water bodies
     Mismatched seams
     Bridge remnants
     Missing data
     Incomplete tiles
     Steep shorelines
     Spikes
                                               Snake Creek Watershed–
                                               Upper Bogue Phalia
Methods- Arc HYDRO


                     Layers Needed to Auto-
                        delineate using Arc 
                        Hydro:

                     §   LiDAR exported to 
                         DEM
                     §   NHD
                     §   Watershed 
                         boundaries
                     §   Aerial imagery
            Methods- ArcHYDRO
§   Fill sinks
§   Use stream network (NHD) for pour 
    points
§   Flow direction and flow 
    accumulation
§   Stream definition and segmentation
§   Catchment grid delineation and 
    polygon processing
§   Drainage processing
§   Joint catchment processing
§   Set nodes using NHD
§   Watershed processing – batch 
    delineation
     §   Section off by watershed level and 
         buffer it so it won’t change
     §   Compare to NHD and aerial and 
         previous watershed delineations
  Quality Control
§ Compare to 
  aerial 
  imagery
§ Compare to 
  NHD
§ Compare to 
  previously-
  delineated 
  watershed 
  boundaries
Stewardship between USGS and 
WBD
 § Contact made with WBD
 § Web Seminars at each major step in the 
   process
 § Guide the GIS specialist in the method 
   and technique 
 § Will ease WBD certification process in 
   the future
                             Requirements 
                             and Standards 
                             of WBD




§   WBD Standards will be 
    updated in March 2012
§   Use current standards 
    until the update
Timeline




  Objective 1: LiDAR burned into USGS NED and QA/QC
  Objective 2: Testing of auto-delineation methods, pilot
   basin delineation
  Objective 3: Completion of sub-watershed delineation of
   NW MS, submission to National WBD
Questions or Comments?


§ WBD- Watershed Boundary Dataset
§ NGTOC- USGS National Geospatial
  Technical Operations Center
§ LiDAR- Light Detection and Ranging
§ EROS- USGS Earth Resources
  Observation and Science Center
§ NED- National Elevation Dataset
§ NHD- National Hydrography Dataset
§ DEM- Digital Elevation Model
Abstract: 
§   Title: Development of Watershed and Sub-Watershed Boundaries for Northwestern Mississippi
§    
§   The National Watershed Boundary Dataset (WBD) for the state of Mississippi lacks sub-watershed delineation in 
    northwestern Mississippi, an area of intense agricultural production locally referred to as the Delta. Previous 
    attempts to delineate watersheds in the Delta to the sub-watershed boundaries were unsuccessful due to 
    topographically-uniform, low relief land elevations; land management practices employed by land owners and 
    growers who frequently change drainage patterns; and the fact that the area did not previously have a sufficient 
    scale of digital elevation data that would allow delineation of subtle topographic features. 
§   Since the publication of the Mississippi WBD by the U.S. Geological Survey in 2009, the entire Delta region has been 
    mapped using Light Detection and Ranging (LiDAR) technology, which has a vertical land surface accuracy of 8.5 
    centimeters (bare earth).  With the availability of LiDAR data, it is now possible to delineate the Delta to the sub-
    watershed level. The U.S. Geological Survey, in cooperation with the Mississippi Department of Environmental 
    Quality, will delineate the sub-watershed boundaries for northwestern Mississippi.
§            The preferred process to delineate river basins in the Delta to the sub-watershed level and to include these 
    into the National WBD is as follows: (1) LiDAR data must be quality-control checked for errors by the USGS-National 
    Geospatial Technical Operations Center (NGTOC) in Rolla, MO, and then integrated into the National Elevation 
    Dataset (NED) by the USGS-Earth Resources Observation System (EROS) Data Center in Sioux Falls, SD; (2) after 
    inclusion into the NED, the  approved Digital Earth Model (DEM)  from the NED can be auto-delineated using  
    ArcHYDRO GIS software; (3) the auto-delineated boundaries are then manually checked and corrected to the DEM, 
    aerial imagery, and the National Hydrography Dataset(NHD); (4) once the auto-delineated boundaries are corrected, 
    WBD tools will be used to re-digitize the boundaries to eliminate line fragments; and (5) names and numbers will be 
    assigned to each sub-watershed polygon and then submitted to the National WBD for certification.
           Definition of Terms
§   HUC: Hydrologic Unit Code (Indicates size of watershed).
§   DEM: Digital Elevation Model
§   LiDAR: Light Detection and Ranging (Remote sensing technology that can 
    measure distance).
§   Watershed: 10-digit HUC (~227 square miles).
§   Sub-watershed: 12-digit HUC (~40 square miles).
     §   5:  Average amount of 12-digit HUCs within one 10-digit HUC
Acronyms
§ WBD- Watershed Boundary Dataset
§ NGTOC- USGS National Geospatial Technical
  Operations Center
§ LiDAR- Light Detection and Ranging
§ EROS- USGS Earth Resources Observation and
  Science Center
§ NED- National Elevation Dataset
§ NHD- National Hydrography Dataset
§ DEM- Digital Elevation Model

				
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posted:4/2/2014
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