Technology Advances But So Do Old-Fashioned Techniques

Pieces of trees and sediment, carefully extracted and preserved, provide a historical view of the environment. Analytical techniques carry names like dendrochronological (dendro=tree, chrono=time) and cryogenic (cryo=frost, genic=generation) core sampling. Tree samples reveal the impacts of past hurricanes on tree growth, as do sediment samples of the life of a marsh, both offering valuable information about the present environment.

Wetland scientists have made use of these technological advances to develop tools that assist their research efforts and offer more detailed information about the resources to be managed. In the studies undertaken after Hurricane Andrew, these tools were used to assess the damage to the coastal environment and predict the long-term effects on valuable coastal resources.

For instance, data loggers for the continuous recording of water elevation, wind speed, and other information had been placed at various marsh sites prior to the hurricane to evaluate marsh management methods. These computers recorded the hurricane as it passed over the sites. They showed that, on August 26, Jug Lake, Louisiana, received wind gusts of 162 kph (101 mph) that were responsible for the extensive tearing of the brackish marsh and its conversion to open water, which is specific, on-the-spot information scientists would not have had otherwise.

Aerial photographs, satellite imagery, and predictive models are also techniques used in studying natural resources. Aerial photographs, taken from airplanes right after the storm, showed immediate loss of spits on barrier islands, the accordion folds in marshes pushed together by winds, and the defoliation and breaking of trees in bottomland forests. Comparisons of aerial photographs taken before the storm, classification of damage type and entry of these classifications into digital data bases, and the use of geographic information systems allowed researches to generate color maps that clearly showed damage that the human eye can miss. Furthermore, similar delineation of images taken from satellites allowed the same kind of damage assessment and will help lead to large-scale analyses of land cover trends. (Figure 22)
 

Figure 22 - Louisiana depicted through Advanced Very High Resolution Radiometer at three different times in 1992. Normally, the area outlined would appear white or similar to the area above it. The pink-purple areas indicate new leaf cover just a few months after the storm. NATIONAL BIOLOGICAL SERVICE

With field data and digital data bases, scientists can develop computer models that simulate the effects of different types of hurricanes on different habitats. Models developed can actually use historical data on wind strength and direction of past hurricanes to predict the probability of hurricane return frequency, as well as the intensity of the winds at remote locations.

But these hurricane studies were also aided by some old-fashioned techniques. Site-specific damage surveys throughout the coastal zone were made by people who actually use the coastal marshes: trappers, hunters, and camp lessees. They provided detailed information about damage to sites that they were most familiar with, and almost all of them knew within a week of the storm exactly what had happened in their areas. The information also helped land managers in setting priorities for repairing storm damage. More information about past storms will presumably be provided by the compilation of oral histories of the Atchafalaya Basin. To balance technology and tradition is fitting because, ultimately, it is the tie between the people and the land hurricanes affect that will teach us the most about the willful winds.

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