Figure 4. Relationships between reach-averaged meander rate and width for Pfafstetter level 3 river basins. The color of each hexagonal bin represents the percent of all observed reaches in that basin that are within the bounds of that bin. “GBM” refers to the Ganges-Brahmaputra-Meghna river basin. The dark red dashed line represents the M = 0.01W relationship proposed by Hooke (1982) as an first-order estimate of riverbank erosion.