title: Spatial analysis of ambient gamma dose equivalent rate data by means of digital image processing techniques.
abstract: A detailed ambient gamma dose equivalent rate mapping based on field measurements at ground level and at 1 m height was carried out at 142 sites in 80 × 90 km area in Pest County, Hungary. Detailed digital image processing analysis was carried out to identify and characterise spatial features such as outlying points, anomalous zones and linear edges in a smoothed TIN interpolated surface. The applied method proceeds from the simple shaded relief model and digital cross-sections to the more complex gradient magnitude and gradient direction maps, 2nd derivative profile curvature map, relief map and lineament density map. Each map is analysed for statistical characteristics and histogram-based image segmentation is used to delineate areas homogeneous with respect to the parameter values in these maps. Assessment of spatial anisotropy is implemented by 2D autocorrelogram and directional variogram analyses. The identified spatial features are related to underlying geological and tectonic conditions using GIS technology. Results show that detailed digital image processing is efficient in revealing the pattern present in field-measured ambient gamma dose equivalent rates and they are related to regional scale tectonic zones and surface sedimentary lithological conditions in the study area.
authors: Department of Chemistry, Institute of Environmental Science, Szent István University, Páter Károly u. 1, 2100, Gödöllő, Hungary. Electronic address: sz_k_zs@yahoo.de.
authors: Katalin Zsuzsanna
authors: KZ
authors: Szabó
authors: Department of Chemistry, Institute of Environmental Science, Szent István University, Páter Károly u. 1, 2100, Gödöllő, Hungary.
authors: Gyozo
authors: G
authors: Jordan
authors: Department of Physical and Applied Geology, Eötvös Loránd University, Pázmány Péter sétány 1/C, 1117, Budapest, Hungary. Electronic address: petrik.atus@gmail.com.
authors: Attila
authors: A
authors: Petrik
authors: Department of Atomic Physics, Eötvös University, Pázmány Péter sétány 1/A, 1117, Budapest, Hungary. Electronic address: akos@ludens.elte.hu.
authors: Ákos
authors: Á
authors: Horváth
authors: Lithosphere Fluid Research Laboratory, Department of Petrology and Geochemistry, Eötvös University, Pázmány Péter sétány 1/C, 1117, Budapest, Hungary. Electronic address: cszabo@elte.hu.
authors: Csaba
authors: C
authors: Szabó
mesh_terms: D001417:Background Radiation; D005720:Gamma Rays; D040362:Geographic Information Systems; D006814:Hungary; D007091:Image Processing, Computer-Assisted; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods*; D062206:Spatial Analysis
keywords: GIS; Geogenic radiation; Mapping