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Track: Oceanography, Coastal Zone, Marine Resources
Marcia Berman
Virginia Institute of Marine Science
PO Box 1346
Gloucester Point, VA 23062
Telephone: 804-642-7188
Fax: 804-642-7182
E-mail: marcia@vims.edu
An Interdisciplinary Remote Sensing Approach to Evaluate the Effectiveness of State Regulatory Programs Which Minimize Impacts to Tidal Wetlands
Defining Issue: The effectiveness of state and federal regulatory programs at minimizing impacts to tidal wetlands within the Chesapeake Bay watershed has recently been questioned. The hopes at obtaining a "no net loss" policy is hampered by continuous requests for residential and commercial construction along shorelines. Albeit small, individual requests are numerous and can collectively eradicate critical wetland habitat in small watersheds. This study combines image processing, GIS, and GPS technology to quantify the relative loss of tidal wetlands over a five-year period from 1989 to 1994. Methodology: Digital color infrared NAPP (National Aerial Photography Program) photography of high resolution was classified within ERDAS to delineate the tidal wetlands from the landscape. A high-order GPS transportation and shoreline survey conducted by the local governments was brought into ArcInfo to register the digital images. A Trimble Global Position Systems (GPS) was used to collect coordinate data for
the location of all sites that had received coastal construction permits that would impact tidal wetlands within the study period. Arc coverages were created so these sites could be superimposed onto the imagery. Finally, a change detection analysis was performed to quantify and spatially identify where tidal wetlands losses have occurred. Here difficult questions regarding accuracy of delineations and assessments must be addressed. These results, when combined with the georeference permitted site, highlight the amount and the location within the landscape where losses can be attributed to human activity. The presentation will focus on the interdisciplinary nature of the technologies required to complete this task and will touch on the importance and value of these tools in addressing resource management questions. This work has been funded by the United States Environmental Protection Agency and the Center for Coastal Management and Policy at the Virginia Institute of Marine Science.
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