engleski

Quantitative comparative geomorpholgical analysis of fluvial and karst relief of Florida

Karst relief of Central Florida and fluvial relief of the Florida Panhandle were analyzed and compared on the basis of standardized samples of karst and fluvial topography derived from digital databases in a GIS environment. Comparative geomorphological analyses of the two distinct genetic relief types were performed on the basis of morphometric parameters derived for each type of relief in general as well as differentially for hypsometric intervals of paleo-marine terraces with the assumption of relative stability of tectonic conditions of the underlying carbonate platform. The comparative analyses conducted indicate overall higher values of the morphometric parameters in the fluvial relief compared to those in the karst relief. This is a consequence of more than two times higher rates of fluvial denudation compared to the karst denudation rates (0.23 vs. 0.11 mm/year, respectively). Differential analyses with respect to the paleo-marine terrace intervals reveal significant quantitative morphological differences between the upper, older and lower, younger terrace intervals in the karst and fluvial relief. In the two older terrace intervals, fluvial and karst denudation rates range from 0.07 to 0.09 mm/year, while in the younger terrace intervals fluvial denudation shows more than two times higher rates than the karst denudation (0.22 and 0.55 vs. 0.11 and 0.19 mm/year), indicating that fluvial processes in the study area are more effective than the respective karst processes. This is clearly reflected in the higher values of vertical dissection and denudated sediment volume in the fluvial relief in the younger terrace intervals, while the increased karst denudation rates are not yet reflected in the respective morphometric parameters due to the slower morphologic response. Overall, long-term karst denudation ranging from 0.07 to 0.19 mm/year is derived by volumetric analysis of the denudated sediment and as such accounts for the effects of both chemical and mechanical denudation. Consequently, they are significantly higher than the previously calculated short-term solutional denudation rates, although their values fall in the mid range of theoretical estimations with respect to climatic conditions of the study area. The obtained fluvial denudation rates ranging from 0.07 to 0.55 mm/year are similar to previous estimates of long-term fluvial denudation.

karst relief ; fluvial relief ; denudation rate ; geomorphometry ; GIS ; Florida

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