First Place

Christopher Brown, University of Alabama
First Place, $5000

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Alligator Bayou Map

E-mail (by winner's request): cbbrown@crimson.ua.edu

“Alligator Bayou” was created using ESRI ArcGIS 9.3 software, as part of an investigation of French colonial longlots in coastal Louisiana. The creation of the final map involved a NOAA land cover dataset (landcover_la_noaa_2005.tif) and Landsat satellite imagery (landsat5tm__la_lsu_2005.sid). Each dataset used the NAD 1983 datum, and was projected according to UTM Zone 15N; both rasters can be located at http://lagic.lsu.edu/loscoweb.

The most technically difficult aspect of the project was the isolation of the longlots; thankfully, though, the surveying system has remained intact to the present-day, dominating parcel alignments throughout the Mississippi River and many of its distributaries. Owing to the location of the study area in the delta, surrounded by wetlands, nearly 100% of the agricultural parcels were historical colonial longlots. Therefore, I was able to isolate these longlots by reclassifying the NOAA land cover dataset, reducing it to the class definitions of “Cultivated” and “Pasture/Hay” However, since not all of the historical longlots preserved their agricultural heritage, I also included developed land by assigning the same value to “ High Intensity Developed” “Medium Intensity Developed,” “Low Intensity Developed,” and “Developed Open Space.”

The final step was the integration of the Landsat imagery with the agricultural areas specified in the land cover dataset. To accomplish this task, I used a spatial analysis mask to extract only imagery within the agricultural land use classes. After applying a stretched symbology, the final map visually delineated each of the longlots and their subsequent subdivisions with different color shades, exposing the spatial extent and patterns of the parcels without the clutter of water or wetlands.

Aside from the visual interest of the differing depths, angles, and alignments of the lots with respect to the hydrology, I suddenly realized that the bifurcation shown in this final map, between the Mississippi River and the Bayou Lafourche (the fork), looked very much like an alligator's head! Because the map is in the delta region, where many alligators live, and the dead space in the map is either water or, in the majority of cases, wetlands (according to NOAA), it should be right at home in its environment! Both from a superficial and historical perspective, I believe that “Alligator Bayou” provides a refreshing way of looking at the cultural hearths of New France, reinforcing both the colonists' mark on the land and, in turn, nature's response.