Laboratory and field GPR measurements to detect qanats

Abstract

Summary Detection of qanats is one of the main geotechnical concerns in the development of cities in most parts of Iran. Using old aerial photos, we have tracked eight qanat systems at Shahid Bahonar University of Kerman (SBUK). To map qanats in detail, integration of ground penetrating radar (GPR) and electrical resistivity tomography (ERT) techniques was proposed. In this paper, we present the results of laboratory and field GPR measurements to detect qanats at the main campus of the university. Laboratory measurements were performed using an IDS 3GHz antenna on a sand box simulating qanats at different scale and equivalent depths. GPR investigations using Mala antenna with the frequency of 250MHz were performed near the buildings that are located on or close to the qanats tracked at the first phase of this research. GPR method has the required resolution to detect qanats, but the problem becomes challenging for deep qanats in radar absorbing soils. ERT technique could be considered as an alternative to map qanats for soils where GPR penetration is poor. We suggest a perspective idea of using drone technology to be integrated with the defined methods to overcome the limitations of geophysical methods.