Harmonization and mapping of terrestrial gamma dose rate data in Belgium

With several databases available, including two sets of in situ measurements of the ambient gamma dose rate and an airborne survey of K, Th, U in soil, Belgium is a favourable case for exploring the mapping methodology for terrestrial radiation. The first step is the harmonization of the different data sets, taking in situ measurements with an ion chamber as the reference. Corrections are made, based on the data themselves (a) to the measurements of permanent monitoring stations, related to their calibration and their layout, including a concrete slab, (b) to the data calculated from airborne measurements, due to the attenuation by the forest cover, and (c) to the data calculated from soil activity, due to the lower activity of the upper layer. After subtracting the cosmic contribution, a harmonized database of the terrestrial gamma dose rate (TGDR) based on 379 in situ measurements was built, together with a harmonized data set of 30134 TGDR values calculated from the concentrations of K, Th, U in soil deduced from the airborne survey. The two datasets are in good agreement with each other for all statistical characteristics that were examined like basic statistics, qq-plots, analysis of variance (ANOVA) or variograms. ANOVA reveals the strong relation between TGDR and the soil class, which justifies the use of a soil map as the framework for developing the TGDR map. The two harmonized TGDR data sets were mapped at the nodes of a kilometric grid, either by simple interpolation (only airborne data), or by the moving average method (for both data sets). There is a rather good agreement between the different maps, although the airborne-based one can obviously give more detail. After reducing the maps to a 10 kmx10 km grid, they have been compared with the European Terrestrial Gamma Dose Rate contained in the European Atlas of Natural Radiation.

CINELLI Giorgia;  TONDEUR François;  DEHANDSCHUTTER Boris;  MENNESON Francois;  RINCONES Jorge; 

2025-09-01

ELSEVIER SCI LTD

JRC126646

0265-931X (online),   

https://www.sciencedirect.com/science/article/pii/S0265931X22000753,    https://publications.jrc.ec.europa.eu/repository/handle/JRC126646,   

10.1016/j.jenvrad.2022.106885 (online),