A New Look at Mustang Island Wetlands: Mapping Coastal Environments with Lidar and EM Jeffrey G
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A New Look at Mustang Island Wetlands: Mapping Coastal Environments with Lidar and EM Jeffrey G. Paine, William A. White, and John R. Andrews Assisted by James C. Gibeaut, Roberto Gutierrez, Tiffany L. Hepner, Rebecca C. Smyth, and Rachel L. Waldinger Bureau of Economic Geology Scott W. Tinker, Director John A. and Katherine G. Jackson School of Geosciences The University of Texas at Austin Austin, Texas 78713-8924 March 2004 ATMOSP ND HE A RI IC C N A A D E M I C N O I S L T A R N A T O I I O T A N N U .S E C . D E ER PA M R OM TMENT OF C A New Look at Mustang Island Wetlands: Mapping Coastal Environments with Lidar and EM by Jeffrey G. Paine, William A. White, and John R. Andrews assisted by James C. Gibeaut, Roberto Gutierrez, Tiffany L. Hepner, Rebecca C. Smyth, and Rachel L. Waldinger A Report of the Texas Coastal Coordination Council Pursuant to National Oceanic and Atmospheric Administration Award No. NA17OZ2353 General Land Office Contract Number 03-005 Bureau of Economic Geology Scott W. Tinker, Director John A. and Katherine G. Jackson School of Geosciences The University of Texas at Austin Austin, Texas 78713-8924 March 2004 i page intentionally blank ii CONTENTS SUMMARY ................................................................................................................................... vi INTRODUCTION .......................................................................................................................... 1 HABITATS AND COASTAL ENVIRONMENTS ........................................................................ 3 Beach ........................................................................................................................................ 3 Dune ......................................................................................................................................... 3 Vegetated-Barrier Flat .............................................................................................................. 6 Fresh-Water and Non-Tidal Marsh ........................................................................................... 6 Fresh and Non-Tidal Pond ........................................................................................................9 Salt- and Brackish-Water Marsh............................................................................................... 9 Wind-Tidal Flat....................................................................................................................... 12 Estuarine Water Body ............................................................................................................. 12 METHODS ................................................................................................................................... 15 Lidar Survey ........................................................................................................................... 15 EM Survey .............................................................................................................................. 17 Vegetation Survey................................................................................................................... 18 MUSTANG ISLAND STATE PARK TRANSECT ..................................................................... 20 Wetland Units and Coastal Environments .............................................................................. 20 Elevation and Vegetation Units .............................................................................................. 27 Conductivity and Vegetation Units......................................................................................... 30 Elevation, Conductivity, and Vegetation Units....................................................................... 37 PORT ARANSAS TRANSECT ................................................................................................... 40 Wetland Units and Coastal Environments .............................................................................. 40 Elevation and Vegetation Units .............................................................................................. 47 Conductivity and Vegetation Units......................................................................................... 50 Elevation, Conductivity, and Vegetation Units....................................................................... 57 LIDAR ADVANTAGES AND LIMITATIONS ........................................................................... 60 iii EM ADVANTAGES AND LIMITATIONS.................................................................................. 61 CLASSIFYING WETLAND AND COASTAL ENVIRONMENTS ........................................... 62 FUTURE WORK.......................................................................................................................... 63 CONCLUSIONS .......................................................................................................................... 63 ACKNOWLEDGMENTS ............................................................................................................ 65 REFERENCES AND RELATED PUBLICATIONS.................................................................... 65 APPENDIX A. MUSTANG ISLAND STATE PARK TRANSECT ............................................ 67 APPENDIX B. PORT ARANSAS TRANSECT .......................................................................... 71 APPENDIX C. PLANTS OBSERVED ALONG MUSTANG ISLAND TRANSECTS ............. 75 FIGURES 1. Location of the Mustang Island study area, Texas Gulf Coast ............................................. 2 2. Map of the Mustang Island area ........................................................................................... 2 3. Profile of a barrier island ...................................................................................................... 4 4. Forebeach and backbeach, MISP transect ............................................................................ 4 5. Fore-island dune ridge (MISP transect) and second dune ridge (PA transect) ..................... 5 6. Vegetated-barrier flat, MISP and PA transects ..................................................................... 7 7. Interior fresh-water marshes, MISP transect ........................................................................ 8 8. Salt-water marsh, PA transect ............................................................................................. 10 9. Low salt-water marsh, MISP transect................................................................................. 10 10. Salt-water marsh, PA transect ............................................................................................. 11 11. Salt-water marsh and tidal flat near MISP transect ............................................................ 11 12. Wind-tidal flats covered with algal mats ............................................................................ 13 13. Estuarine water bodies, PA transect.................................................................................... 14 14. Relationship between apparent conductivity measured in the horizontal dipole orientation at 0.6 m and at the ground surface...................................................................................... 19 15. Relationship between apparent conductivity measured in the vertical dipole orientation at 0.6 m and at the ground surface.......................................................................................... 19 iv 16. Aerial photomosaic of the MISP transect showing 1992 NWI habitats ............................. 21 17. Digital elevation model (DEM) of the MISP transect showing 1992 NWI habitats .......... 22 18. Distribution of coastal environments along the MISP transect for each NWI unit ............ 25 19. Elevation profiles along the MISP transect ........................................................................ 28 20. Elevation profile superimposed with 1992 NWI units, MISP transect .............................. 29 21. Elevation profile superimposed with coastal environments, MISP transect ...................... 32 22. Apparent ground conductivity measured along the MISP transect .................................... 33 23. Apparent conductivity profile superimposed with 1992 NWI units, MISP transect .......... 35 24. Apparent conductivity profile superimposed with coastal environments, MISP transect.. 36 25. Elevation and apparent conductivity profiles, MISP transect ............................................ 38 26. Elevation and conductivity of NWI units and coastal environments, MISP transect......... 39 27. Aerial photomosaic of the PA transect showing 1992 NWI habitats ................................. 41 28. DEM of the PA transect showing 1992 NWI habitats ........................................................ 42 29. Distribution of coastal environments along the PA transect for each NWI unit................. 45 30. Elevation profiles along the PA transect ............................................................................. 48 31. Elevation profile superimposed with 1992 NWI units, PA transect ................................... 49 32. Elevation profile superimposed with coastal environments, PA transect ........................... 51 33. Apparent ground conductivity measured along the PA transect ......................................... 53 34. Apparent conductivity profile superimposed with 1992 NWI units, PA transect .............. 55