Modified hydrogeomorphic approach for estimating quantitative change of riverine wetland functions

Abstract

HydroGeoMorphic (HGM) approach could examine relatively more details for wetland functions. However, HGM cannot be utilized in assessing the functional improvement of wetlands because it is limited to evaluating the similarity between the reference and the target wetlands. Therefore, this study proposes the Modified HydroGeoMorphic (MHGM) approach for considering better functions of target wetlands. The values of Index of Function (FCI) and variables in HGM are in the range of 0.0 to 1.0 and so, in MHGM, we redefine the values of variables in 0.0 to 2.0 to find a better function for the target wetland. Based on the monitored variables, FCIs for the wetland functions were estimated and the functions of dynamic surface and subsurface water storage, spatial structure of habitat, and maintaining the distribution and abundance of vertebrates in Imjin riverine wetland as a target wetland showed better FCIs than those of Hwapo which is a reference. This means that MHGM reflects an actual change in FCI, leading to a more favorable evaluation of the target compared to the reference wetland. This indicates that MHGM considers actual functional progress of wetlands by improving HGM's limitations in assessing change.