Abstract

SOARES, Geana Sousa  and  DOMINGUEZ, José Maria Landim. Wetlands on Itapicuru River coastal plain, Northern littoral of the state of Bahia, Brazil: classification and environmental controls. RGCI [online]. 2012, vol.12, n.2, pp.223-337. ISSN 1646-8872.

The wetlands of the Itapicuru river coastal plain are the most important of all the Northern littoral of the state of Bahia. The origin and evolution of these wetlands are intrinsically related to the Quaternary sea level changes. Along the coastline of Brazil sea level has dropped 3 to 4m during the last 5.600 years BP. Estuaries and lagoons formed during the maximum of the Holocene transgression progressively evolved to freshwater wetland as a result of this drop in sea level. Nowadays the wetlands occupy the low lying areas separating Pleistocene and Holocene sandy terraces, and the bottom of valleys not completely infilled with fluvial sediments. This study used an existing GIS database, complementedby fieldwork, to classify the Itapicuru coastal plain wetlands, to establish its environmental controls and to evaluate the environmental services provided by these wetlands. The wetlands were classified using their hydrogeomorphic attributes. Terms such as depressional fed groundwater, tidal fringe among others incorporate useful information concerning the structure and functioning of the wetland ecosystem including their significance in providing environmental services. The rationale behind the hydrogeomorphic approach is that the major types of wetlands can be fundamentally differentiated by parameters related to topography and water retention capacity. The classification presented herein has two immediate repercussions. Firstly it provides a framework for data collection, not only to organize existing data but also in the planning of future investigations. Secondly, and may be most important, this classification allows governmental organizations to establish goals for the creation of specific legislation for biological conservation on these areas, since the classification used is based upon the hydrogeomorphic attributes to differentiate wetland classes.

Keywords : wetlands; wetland's services; hydrogeomorphic classification.

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