GEOPHYSICS IN TOWN-PLANNING - A CASE-STUDY

Geophysical surveys as aid to urban evaluation in the Vidyadhar Nagar area adjacent to Jaipur city, Rajasthan, have been conducted. DC resistivity surveys over area covered by sand and dunes indicated the presence of a moderately thick surface layer underlain by a potable aquifer zone of substantial thickness over quartzite bedrock of even topography deepening towards southwest. The results of the magnetic survey show, in general, normal structural behaviour barring a high in the southwest part of the area. The high is explained as due to an intrusive feature at a considerable depth, hence inconsequential for town planning . Subsequently, Jaipur Development Authority has undertaken construction of urban complex with a high rise structure in the area. The paper presents the geophysical results along with chemical analysis of ground water and computer studies. The soundings reveal the suitability of the area for urbanisation, considering the presence of moderately thick surface horizon underlain by a promising aquifer formed over the quartzite bedrock of even topography and disposition. The order of the resistivity obtained and the chemical composition of ground water show the ground water to be of good quality for drinking purpose.