Tampa Bay Integrated Science Pilot Study:

Baseline mapping, land surface dynamics and predictive modeling, and hazards vulnerability studies

Results/Discussion

Figure 2. This DEM of the Tampa Bay area uses a combination of hill-shading and color tinting to depict relief, which ranges from a depth of 94 feet below sea level at the mouth of the Bay (dark blue) up to a height of 105 feet above sea level in Clearwater.
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A seamless, high-resolution, DEM has been produced for the immediate environs of Tampa Bay by merging the best currently available bathymetric and topographic data (Fig. 2).

Differences in datums, formats, projections, quality, accuracy, age, and resolution associated with the two types of data were resolved by creating a common framework. This enables other high-resolution data to be integrated into the DEM as they become available.

The DEM will be expanded in the near future to provide coverage of the entire drainage basin. Hydrographic charts and topographic survey maps dating from the 1800’s and early 1900’s will be used to create historical DEM’s of the region that enable changes in the configuration of the coastline, land surface, and sea floor to be determined.

Using a wide variety of sources including historical imagery, aerial photography, maps, and digital data, multitemporal data layers are also being developed for land cover and land use, areas excluded from development such as parks and cemeteries, urban land (Fig. 3), transportation features, and hill-shading, which imparts a 3-dimensional look to the terrain.

The DEM’s and regional geospatial data sets provide critical baseline information that support other scientific investigations being conducted under the pilot study, and support numerical modeling efforts.

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Figure 3. Urban extent for a portion of the Tampa Bay region is portrayed in red above. Note the increase in urbanization from 1972 (left) to 1992 (right).

The SLEUTH Model is being run on a Beowulf cluster of PC computers that provide processing power approaching supercomputer capability (Fig. 4). The Model will be run to simulate urban growth from 1950 to the present day, and to predict urban growth patterns out to the year 2050.

Similarly, major land cover categories will be modeled for the same time span to study potential impacts to ecosystems in the region. Scientists hope to couple other models with SLEUTH and investigate the relationships between land surface dynamics and the dynamics of the benthic environment.

Figure 4. Beowulf clusters such as this provide the processing power of a supercomputer at a fraction of the cost.

The rapid growth being experienced in the Tampa Bay drainage basin is placing an ever-increasing proportion of the population and attendant development at risk from the variety of natural disasters that characterize this region of the United States.

Using the baseline mapping data in conjunction with other data available from Federal, State and local government agencies, and the urban growth predictions from SLEUTH, a geographical analysis is being conducted of the current and anticipated future vulnerability of the population and built environment to hurricanes, storm surges, flooding, coastal erosion, tornadoes, ground subsidence, wildfires, and high winds.

The study will address historical changes that have occurred in the location and configuration of the coastline, changes in the distribution and density of the population, housing, commercial and industrial sectors, and land valuation. Socio-economic characteristics of the population will also be factored into the analysis.