Figure 4
(a) The Chi (χ)-map of Siang-Dibang drainage divide region show the divide is in disequilibrium and migrating towards Dibang catchment. (Also see SM6). The tributaries across wind gap at the divide used for further analysis. (b) River profiles of tributary channels across the fixed drainage divide. The dotted and solid profile are tributaries of Siang and Dibang rivers, respectively. The profiles of Db. 7.2 and Db. 6.2 (red and pink, respectively) show unique flat relict landscape at ~3600 m elevations and co-planar landscape on either side of the divide. (c) The stacked swath profile with 1σ variation of flat relict landscape show broad misfit channel floor across the divide. (d) χ-elevation profiles across drainage divide clearly suggests that the tributaries of Siang are aggressor and encroaching the drainage area of victim Dibang catchment. Note the equilibrium behavior of yellow & black channels suggesting the extent of water divide.
