Fig. 4. Areas of mudlump development at major distributary mouths, Mississippi River delta. (After Morgan, Coleman, and Gagliano, 1968). Although analysis of environmental data has not progressed to the point where a specific site can be recommended, the relative merits of large coastal sectors in the vicinity of the lower delta can be evaluated on the basis of the major factors previously discussed. Four major sectors are identified in Figure 6. A fifth area for consideration, Chandeleur Sound and vicinity, lies beyond the map margin. The Chandeleur area has a broad shoal shelf and can probably be ruled out because of the great distance to the 100-foot contour. In the Breton and Main Pass areas current patterns are unfavorable. Foundation conditions rule out most, if not all, of the South Pass area. Hence from preliminary analysis, the West Delta seems to have a favorable combination of factors for further consideration. Fig. 6. Major areas of consideration for Superport location in the vacinity of the lower Mississippi River Delta. III. RELATIONSHIPS TO ESTUARINE ZONE Environmental Management Areas From the standpoint of renewable resources and scenery or esthetics it is useful to identify the major environmental management units in the Louisiana coastal zone. As shown in Figure 7, the coastal zone can be segmented into fourteen management areas. Four of these are large, fresh water basins dominatd by extensive swamps, shallow, muddy rounded lakes and fresh marsh. Eight major estuarine management regions can also be defined. Salinities, in general, range from brackish to saline. These areas are characterized by extensive stands of transitional and saline marshes, innumerable shallow ponds and lakes, and large shallow bays with irregular shoreline. The Grand-White unit, although classified as estuarine, is dominated by fresh marsh and large freshwater lakes and is managed as a reservoir for southwestern Louisiana's rice farming district. These estuarine management areas are biologically the most productive places in Louisiana and represent the state's most important renewable resource. Two controlled delta building units are indicated in Figure 7. Under present conditions these are freshwater bays and marshes in close proximity to active distributary outlets of the Mississippi and Atchafalaya rivers. In such places delta building processes are usually the rule. Both areas have tremendous potential for land building and environmental management. |