LAND USE DATA AND TYPE MAPPING 



Previous studies had proven the usefulness of 

 remote sensing techniques for coastal mapping. 

 They had also proven this tool to be cost-effective, 

 efficient, and relatively accurate. The degree of ac- 

 curacy, however, depended upon the resolution de- 

 sired. Techniques tested in devising a methodology 

 suitable for ecological characterization were 

 Landsat imageiy, black and white photographs, 

 infrared imagery, aerial and ground obsen'ations, 

 and various combinations of these. 



Landsat imagery was tested with the most 

 sophisticated equipment available at Bendix Cor- 

 poration, Ann Arbor, Michigan and National At- 

 mospheric and Space Administration, Slidell, Lou- 

 isiana. Training sites were adequately identified by 

 ground truth to identify spectral signatures dis- 

 played on Landsat imager^'. Maps were quickly 

 generated by this procedure in pilot study areas 

 and quantitative data were displayed according to 

 the frequency of various signatures. 



Resolution appeared to be within acceptable 

 limits. However, checks of the maps generated in 

 this manner revealed that there was not always a 

 distinct signature for each habitat; consequently, 

 map displays sometimes differed significantly from 

 actual conditions. 



Coastal marshes make up a large portion of the 

 Chenier Plain and they contain a wide array of 

 plant species varying in composition, density, and 

 growth stage. These differences could not be ade- 

 quately categorized from Landsat scenes, as re- 

 quired for the characterization process. 



The procedure that proved most desirable is 

 similar to that currently used for the National Wet- 

 land Inventory being conducted by the Fish and 

 Wildlife Sei^vice. This procedure requires a combi- 

 nation of data obtained from infrared imagery and 

 other aerial surveys. Aerial sui"veys by persons able 

 to identify plant types from low-level flights over 

 the area are a strategic part of this type mapping. 

 This procedure, coupled with land-use mapping 

 from black and white photographs, produced data 

 with accuracy satisfactory lor characterization 

 purposes. Also, this procedure proved to be more 

 cost-effective than all other adequate procedures 

 tested. 



PILOT STUDY 



The overall objective of the pilot study was to 

 gather sufficient information to develop a "mini- 



atlas," which was used by project reviewers and 

 others to evaluate a "finished" product with re- 

 spect to the cost effectiveness of specific methods 

 used, and the usefulness of the information to 

 prospective users. In addition, it provided oppor- 

 tunities for the researchers to correct any misjudg- 

 ments and possibly give insight to new methods. 

 Data processing included investigation of data 

 availability, collection, coding, analysis, and pre- 

 sentation. Data gaps were identified and filled 

 where possible. 



Criteria initially used for selection of the pilot 

 study area included that the area be large enough 

 and variable enough to be representative of the 

 problems encountered over the entire Chenier 

 Plain, and that previous investigations completed in 

 the area would provide adequate background data 

 for characterization. Those involved in the actual 

 choosing of the site deemed that these criteria 

 alone were insufficient to permit a final decision. 

 Other criteria, therefore, had to be considered. In 

 brief, some of these additional factors used were: 



1 . A representative display of habitats was lo- 

 cated within the area. 



2. A major urban complex was located within 

 the basin. 



3. Prevalence ot petro-chemiciil industries. 



4. Diversified fisheries and wildlife resources. 



The pilot study concept proved to be an effec- 

 tive part of the characterization process. It met the 

 primary objective of providing a preliminary for- 

 mat which could be reviewed and modified to 

 maximize the effectiveness of the final product in 

 meeting needs of user groups. 



CHARACTERIZATION STUDY 



The general structure developed for the pilot 

 study was used for the characterization atlas. This 

 facilitated assessment and, to some degree, made 

 known what could be expected in the final charac- 

 terization atlas. Results were presented in several 

 forms; maps, figures, tables. The written portion of 

 the atlas was designed, to the extent possible, to 

 stimulate the use of the material by resource man- 

 agers. 



Drafts of the atlas, maps, and other documents 

 that are considered as the final products of the 

 Ecological Characterization of the Chenier Plain 

 are being reviewed and revised, and should be pub- 

 lished during 1978. 



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