K S Valdiya
Neotectonics and Environmental Geology
hello Identification of belts where sudden and swiftly occurring geological phenomena often destabilize the natural configuration of life and threaten the balance of ecosystems, is the principal objective and the main thrust of activities of this one-man Unit. Regions vulnerable to landslides and occurrence of earthquakes repeatedly in the central sector of the Himalayan arc (Kumaun in the Uttaranchal), the Biligirirangan Range in southeastern Karnataka, and the Sahyadri Range in western Karnataka and central Kerala are taken up for studies. Various signs of physical changes taking place in the natural systems in the study areas are interpreted through analysis of patterns in topographical maps and satellite imagery, intensive as well as extensive field work, interpretation of uncommon behaviours of rivers and streams in response to continuing tectonic movements, and visual observations of common hazard indicators.
The field-based studies carried out in the last decade demonstrated that geomorphological rejuvenation of landforms, changes in courses of rivers, their anomalous knee bends, and their blockages manifesting itself in the formation of lakes and subsequent development of flat ground of black-clay deposits, modification of landform due to acceleration of gully erosion, development of mountain/hill barriers along active faults in southeastern Karnataka and adjoining Tamil Nadu, the southern Sahyadri and its foothill-belt in central Kerala and in the Sor Valley in eastern Kumaun in Uttaranchal Himalaya, are related to continuing movements on ancient faults. It is realized that the reactivation in the present time of older faults is contributing towards relaxation of strain in the earth's crust in these earthquake-prone belts. Another area of study is the delineation of a regional terrane-defining boundary fault in the High Himalaya, gaining insight into the mechanism of recent movements on it, and obtaining information on the changes taking place.
Another area of activity is the writing of books in simple language for students and researchers in geology, as well as laymen.
Key Publications: Books
1. Valdiya KS. Dynamic Himalaya, Universities Press, Hyderabad, 1988.
2. Valdiya KS. Himalaya: Emergence and Evolution, Universities Press, Hyderabad, 2001.
3. Valdiya KS. Saraswati:The River that Disappeared, Universities Press, Hyderabad, 2001.
4 Valdiya KS. Geology, Environment and Society, Universities Press, Hyderabad, 2004.
5. Valdiya KS. Understanding Earthquakes and Landslides: Preparing for Hazards, DST, New Delhi, 2004.
Selected Research Papers
Valdiya KS. Trans-Himadri fault: Tectonics of a detachment system in central sector of Himalaya. Jour. Geol. Soc. India, 65, 537-552, 2005.
Valdiya KS. Tectonic resurgence of the Mysore plateau and surrounding regions in cratonic southern India. Current Science, 81, 1068-1089, 2001.
Valdiya KS. River response to continuing movements and the scarp development in central Sahyadri and adjoining coastal belt. Jour. Geol. Soc. India, 57, 13-30, 2001.