Section II. Materials
Item I. National Wetland Inventories
The National Wetland Inventories (NWIs) were used as the basis for comparison in the study. NWIs were developed from 1992 1:65,000 scale photography. These photos provided the type and acreage of wetlands present in 1992.
Projection information for this data is as follows:
Projection: UTM
Datum: NAD27
Units: Meters
Zone: 14
Item II. Reference Data—Lamberts and Digital Ortho Quarterquads
The reference data was used to determine the amount of wetland loss. By comparing the NWIs (1992) to the reference data (at the most 7 years later), the amount of wetland loss with respect to the NWIs could be determined.
1/2 Meter Lamberts. The 1/2 meter Lamberts were used for the portion of the study area covered by Galveston and Houston Counties (they were not available for Chambers county—see Figure 2). Lamberts were processed by the firm of Andrew Lonnie Sikes, Inc. and purchased by members of the Houston-Galveston Area Council’s Geographic Data Committee. These digital images were developed from true color photography flown between January 1999 and January 2000.
Projection information for this data is as follows:
Projection: State Plane Coordinate System
Datum: NAD83
Grid System: Lambert
Units: Feet
Zone: Texas South Central (5401)
|
