Testing a Soil Magnetometry Technique in a Highly Polluted Industrial Region in North-Eastern Germany

Abstract

The paper presents the results of a study in the region Dübener Heide (Central Germany) testing the suitability of field measurements of magnetic susceptibility for the detection of historical fly-ash deposition. The measurements supported the verification of historically documented deposition zones along an emission gradient. Mean values, standard deviation, and coefficient of variation can be used to characterize the former deposition zones, although the study revealed several problems, which will be the subject of future work: (1) the volume susceptibility measurements used in the study do not allow the calculation of the actual fly-ash amount stored in the soil and thus must be calibrated with correction factors from laboratory measurements; and (2) measurements in regions with similar conditions but without fly-ash deposition are needed to obtain reference values for the natural range of magnetic susceptibility.

Mapping of ferrimagnetic susceptibility for screening of fly ash deposition

“…Considering the spatial variance of magnetic susceptibility, the highest single values were observed at the Western part of Dübener Heide, which was situated nearest and in the major regional wind direction to the former power plants. Here, also the broadest variability of the measured values was observed, which is supported by results of a pre-study (Fürst et al [7]). The lowest values and the lowest variability were observed in the Northeastern part of Dübener Heide, which is situated farthest from the power plants.…”

“…For the regionalization of magnetic susceptibility by use of a stepwise multiple regression approach in combination with geo-kriging, mean values of magnetic susceptibility measurements at three depth levels in the 1x1 km² raster were used: Depth level 6-10 cm represents the zone in the humus layer, where in average, the highest magnetic susceptibility values were observed (Fürst et al [7,8]). For this zone, biased measurements can be excluded which can occur at the interface between airspace and humus layer (depth level 0-5 cm) due to technical particularities of the sensor.…”

“…Impacts of fly ash deposition on chemical humus and soil properties are still evident (Fritz et al [5], Fritz and Makeschin [6], Fürst et al [7][8][9], Klose et al [13], Klose and Makeschin [11], Koch et al [15], Koch et al [14]). However, the former forest growth and decline based definition of deposition zones cannot be used anymore due to considerable changes in regional forests health and species composition since the first inventories of Enderlein and Stein [3] and Lux [20].…”

Regionalization of Magnetic Susceptibility Measurements Based on a Multiple Regression Approach

“…Starting at the nearest power plant in Zschornewitz, Dübener Heide is situated in a horizontal distance of 8 km (western boundary)-50 km (eastern boundary) to the emitters. The area is known to be one of the most polluted forest ecosystems in Germany with more than 100 years history of industrial deposition: based on the available monitoring information, the deposition in the period 1910-2000 is estimated to amount to approximately 18 Mio.tons of fly ash and 12 Mio.tons of SO 2 (Fürst et al 2007a(Fürst et al , 2009. When extrapolating the above mentioned emission quantity of 0.3 Mio.tons of fly ash per year to a period of about 100 years, the real deposition amount could be even higher.…”

“…As an example, fly ash from combustion of fossil fuels is known to be stored in forest sites for many decades Makeschin 2003, 2005;Fürst et al 2007aFürst et al , 2009). Its average geochemical composition comprising mostly sulfur oxides, metal oxides, and black carbon is variable in dependence from the origin of combusted material (Magiera and Strzyszcz 2000;.…”