A methodology for the determination of lithology-based thermal conductivities at a regional scale is proposed, assigning a saturated and unsaturated thermal conductivity to each stratigraphic unit encountered in the region. Such a methodology is paramount for GIS-supported mapping of shallow geothermal energy at a regional scale. The analysis is primarily based on the interpretation of thermal response tests (TRT), assuming that the thermal conductivity determined during TRT is a thickness-weighted average of the individual thermal conductivity of each stratigraphic unit constituting the ground along a ground heat exchanger (GHE). Enhanced thermal response tests, reference geological material-based thermal conductivities and laboratory optical scanning tests achieved on remolded specimen from drilling cuttings are used to validate the results. The relevance of the methodology is illustrated through its application to the Brussels-Capital Region (Belgium), and consistent saturated and unsaturated thermal conductivities are obtained for each stratigraphic unit. An uncertainty analysis on the thermal conductivity is proposed, and its impact on the design of GHE is discussed. In most cases, the relative error on the ground thermal conductivity is lower than 10 %, and its impact on GHE length remains limited.

提出了一种在区域范围内确定基于岩性的热导率的方法，为该区域遇到的每个地层单元分配了饱和和不饱和的热导率。这种方法对于区域地理信息系统支持的浅层地热能地图绘制至关重要。该分析主要基于对热响应测试（TRT）的解释，假设在TRT期间确定的热导率是构成沿地面热交换器（GHE）的地面的每个地层单元的各个热导率的厚度加权平均值。 。增强的热响应测试，基于参考地质材料的热导率以及对来自钻屑的重塑样品进行的实验室光学扫描测试均用于验证结果。通过将其应用到布鲁塞尔首都大区（比利时）来说明该方法的相关性，并为每个地层单位获得了一致的饱和和非饱和导热系数。提出了导热系数的不确定性分析，并讨论了其对GHE设计的影响。在大多数情况下，地面导热系数的相对误差低于10％，并且其对GHE长度的影响仍然有限。