Development of a thermal conductivity map of Stockholm

Abstract

New methods have been suggested to spatially extend in situ thermal response test (TRT) assessments based on geostatistical analysis. These methods can be used to determine a stochastic distribution of the subsurface thermal conductivity beyond the test borehole on larger scales by interpolating the data with geostatistics, including sequential Gaussian simulations (SGS) used in the present study. This paper presents a simulated thermal conductivity map for Greater Stockholm in Sweden, based on the SGS method with input data from in situ measurements (TRT and DTRT). The geology of Stockholm is used as a background raster in the simulations, based on bedrock maps from the Geological Survey of Sweden (SGU). The resulting maps are compared with a point map of punctual ground thermal conductivity of Greater Stockholm earlier derived by SGU, compiled from laboratory data that were obtained by thermal conductivity scanning and modal analysis of surface rock specimens of the area.