The isobase map (local base-level map) represents the erosional stages and it gives a strong relationship between different Strahler order streams and the local erosion al conditions in a changingtopography. This approach is quick, efficient and reliable to delineate neotectonic influence within the same rock types. In this research, we evaluate the geomorphic landforms of Pothowar Plateau and Kalabagh fault zone using local base level approach. The purpose is to demarcate boundaries and to see whether they are influenced by the active tectonics or lithologic difference. For this purpose, we extracted the drainage network in the form of second and third order Srahler streams and automatic lineaments (by Houghman transformation)from SRTM 90m DEM. The isobase map was constructed based on the points of intersection of automated contours from the DEM and with the selected stream orders. We observed different base-level anomalies that relate to the prominent neotectonic features and lithological boundaries as presented in the published geological maps. The orientation, deflection and disconnection of the isobase lines correspond well with the local structures in the study area.
