Selection of Preferred Floodplains for the Renaturalization of Hydrologic Functions: A Case Study of the Paraiba do Sul River Basin, Brazil

The primary goal of this study is to identify floodplains that are in large river basins and could potentially undergo renaturalization of their hydrologic functions. The study area is the Paraiba do Sul River Basin (55,400 km(2)), which is located in southeastern Brazil. The field work included the application of geoprocessing techniques (ArcGIS 10 and ENVI 4.7) for the delineation and individualization of the floodplain, and the following characteristics were surveyed: area, perimeter, circularity index and urbanization index. Discriminant and cluster analyses (SPSS 15) were performed, and 77 floodplains were found that exhibited a wide variation in area (0.13 to 1,540 km(2)) and perimeter (1.8 to 4,200 km), low circularity indices (< 0.52), and a low average urbanization index (18.9 %). The floodplains were grouped according to how well the renaturalization of their hydrologic functions could be managed and categorized as follows: a) low management potential (9 units); b) medium management potential (15 units); and c) high management potential (52 units). The discriminant analysis correctly classified 100 % of the cases, which indicates that the model has a high predictive ability and can accurately classify the management potential of floodplains.