Geometric attribute and shape characterization of modern depositional elements: A quantitative GIS method for empirical analysis

1696 Wave- and fluvial-derived elements from the Mitchell Delta were analyzed using our CA method and the conventional minimum bounding box (MBB) approach. The MBB results defined the regression slopes as 1.25-4.47 times wider and 0.31-0.97 times shorter than their CA values. Results applied to 2221 mid-channel bar elements in the Congo River showed similar CA and MBB relationships, with linear regression slopes of a MBB as 1.06 times wider and 0.97 times shorter. The inconsistency in the comparative MBB and CA results for these two datasets is attributed to the very different geometries of the sandbodies in these contrasting depositional environments. This suggests that caution should be exercised when applying current methods. A major benefit of the proposed CA method is that it allows quantitative study at scales and levels of detail typically not practical using manual solutions.