Morphometric analysis of landforms on basalt, granite gneiss and schist geological formations in north Karnataka, India – a comparison

Abstract

Morphometric analysis reveals the development of land surface processes and provides an insight into hydrologic behaviour of watershed. A morphometric analysis of landforms on basalt, granite gneiss and schist in north Karnataka was conducted with the objective of comparing various morphometric parameters among them. A sub-watershed each was selected to represent landform on basalt, granite gneiss and schist. The stream length was highest in sub-watershed on basalt and was least on schist with one on granite gneiss being intermediate. The stream number was highest in basalt and its values were similar in granite gneiss and schist. Total relief, relief ratio and ruggedness number were distinctly high in sub-watershed on schist compared to the other two. The low mean bifurcation ratios in all three sub-watersheds suggested stability of the landforms. Drainage density was relatively coarser in the sub-watershed on granite-gneiss compared to the other two. The drainage network was dendritic in the sub-watershed on basalt, sub-dendritic on granite gneiss and sub-trelis on schist. The drainage texture and texture ratio were slightly higher, overland flow values were lower in sub-watersheds on basalt and schist compared to that on granite-gneiss. All three sub-watersheds exhibited similar elongation ratio, form factor and circularity ratio.

Keywords

• comparative morphometry
• dem
• drainage pattern
• geological formations
• sub-watersheds