Magnetic studies of natural and man-made processes of critical infrastructure objects at the area "Glinka"

The results of magnetic soil and underlying rocks studies at the area near Lake Glinka are considered. This study was performed as a part of the landslide investigation of the urban environment of the Kyiv agglomeration. The aim was to detect the natural and man-made processes affecting critical infrastructure. Under field condition we measured the volume magnetic susceptibility of soil κ (10-3 SI), and sampling was performed. Under laboratory conditions we measured and then calculated the mass-specific magnetic susceptibility χ (10-8 m3/kg), and its frequency dependence χFD (%). The soil of the study area is gray forest (Greyic Phaeozems Albic in WRB) with signs of urban soil. Magnetic studies were conducted at two points on the high landslide bank of the Lake Glinka, as well as on the opposite low bank. On the low bank, we organised measurements and sampling along the micro-catena and at the vertical soil section to study the soil genetic horizons. Magnetic polygons were constructed based on cosmography downloaded by ArcGIS. The classification of the polygons is made by the attracting the magnetic susceptibility and its frequency dependence. We identified the polygon with the highest values of magnetic susceptibility (χ = 54 × 10-8 m3/kg) and the lowest value of frequency dependence (χFD = 3.6 %). This is the soil with man-made pollution. Two polygons with similar values of magnetic parameters were identified: χ = 25-35 × 10-8 m3/kg, χFD = 8-10 %. Such values are related to the natural soils. Three polygons (two on the the low bank and one on the high landslide bank of Glinka) have average intensity values of magnetic parameters: χ=35-40 × 10-8 m3/kg, χFD = 6-7 %. The vertical distribution of soil magnetic parameters in genetic horizons was observed and the redistribution of magnetic matherial was detected. Such kind of the redistribution indicates the erosion processes. The magnetic properties of soils are important for the joint interpretation with electric tomography, GPR measurements, and GIS analysis of the national landslide database of Ukraine. The results are useful for the development of the algorithm for the environmental monitoring of the critical infrastructure at the urban area.