Detection of sub-surface spaces, using thermal infrared images in Shiramin region, Azarshahr, Iran

Subsurface spaces make restrictions for site selection and construction of structures. Although geophysics and drilling help engineers in this issue, but these are cost effective and time consuming. Therefore economic and fast methods should be considered for explorations. In this article an attempt was made to introduce a method for detecting and mapping subsurface spaces using thermal infrared images and other environmental effective factors. Assumption is land surface temperature somehow is being influenced by subsurface temperature. By the time the general conditions of land surface in carbonate rocks to be the same in terms of vegetation cover, antecedent soil moisture, illumination and altitude, any variations and anomalies of temperature on land surface may be attributed to inherent physical and hydrogeological conditions of carbonate rocks. Investigations showed that some parts of carbonate rocks in Shiramin region that are hosting subsurface spaces are relatively appeared cooler than the others on thermal images. Data integration based on applying base rules was taken place by means of ILWIS GIS and data analysis tools. As a result of such data integration, thermal anomalies related to inherent condition of carbonate rocks were identified and consequently spatial distribution map of areas hosting unseen subsurface spaces were prepared.