Landsat analysis of Dhansiri valley

Detailed Landsat imagery interpretation was carried out in Dhansiri Valley, Lower Assam, employing the standard visual interpretation techniques. Optico-electronic analysis using 1²15 Video Image Processer was also carried out. Edge enhancement of the imagery using photographic methods was found to sharpen lineaments to a great extent. As many as fifteen localities have been identified as “anomalies” reflecting possible subsurface structures. The delineation is based on different factors including tone, texture, drainage etc. Prominent structural trends delineated are in NE-SW and ENE-WSW directions. The NE-SW trending Borholla-Mikir hills fault zone divided the valley into two distinct structural units, the relatively shallower northern sector dominated by the ENE-WSW trending faults and the southern sector comprising the Dhansiri-Diyung flood plains dominated by tne NE-SW trending faults.