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Radiocesium v zemědělsky neobdělávaných půdách

The diploma thesis Radiocaesium in agricultural uncultivated soils is focused on creation literary review, collection soil samples and then preparation of samples for gamaspectrometric analysis to determine content of the radionuclide (137Cs). In the first part of literature review radiocaesium and its sources in the environment are characterised. Radiocaesium transport in atmosphere, the 137Cs deposition on soil and its influence on human is included. In the next part, soil parameters, behaviour of radiocaesium in soil, following countermeasures, differences between soils in agroecosystems and agricultural uncultivated soils, contamination of soils with radiocaesium in Czech Republic are described. Materials, methodology and description of chosen locations are followed. The main part of the thesis is focused on determination of radiocaesium content in uncultivated soils. In 2013, soil samples (57 samples of 5-cm-top A organic profiles and 57 samples of deeper B mineral profiles from 5-12-cm of depth) were taken from four selected locations: Valašské Meziříčí-Juřinka, Velké Karlovice, Loukov, Prostřední Bečva. Soil samples were always collected in three specific areas: meadow, deciduous forest (mixed forest) and coniferous forest. The lowest values of 137Cs activity in soils were observed in Juřinka (average value in profiles A 16.9 +- 4.29 Bq.kg-1 and B 11.6 +- 2.53 Bq.kg-1), then in Loukov (average value in profiles A 38.8 +- 30.22 Bq.kg-1 and B 18.6 +- 12.60 Bq.kg-1). The highest values 137Cs in Velké Karlovice (in profiles A 64.7 +- 44.11 Bq.kg-1 and B 30.1 +- 21.50 Bq.kg-1), lower values in Prostřední Bečva (in profiles A 46.6 +- 30.01 Bq.kg-1 and B 24.9 +- 28.50 Bq.kg-1) were measured. Significant differences between 137Cs activity in top A soil profile and deeper B profile in all four locations were found (T-test, P less then 0.05). In all locations, the highest average values radiocaesium activities were observed in coniferous forest (average values in profiles A 65.7 +- 41.91 Bq.kg-1 and B 35.03 +- 28.94 Bq.kg-1), then in deciduous forest (average values in profiles A 33.8 +- 17.27 Bq.kg-1 and B 20.1 +- 7.51 Bq.kg-1) and the lowest in meadows (average values in profiles A 14.9 +- 4.53 Bq.kg-1 and B 10.7 +- 3.63 Bq.kg-1), (P less then 0.05). The 137Cs activities in soil profiles were converted from the radiocaesium activity concentration (Bq kg-1) to the 137Cs depositional density (kBq m-2), and the densities ranged from 0.93 to 12.94 kBq m-2. Results were processed to tables, graphs and map. In the closing part of thesis, our results were discussed and compared with published data and ecological importance of radiocaesium activity in agricultural uncultivated soils was also assessed.

Identiferoai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:179465
Date January 2014
CreatorsKubějová, Michaela
Source SetsCzech ETDs
LanguageCzech
Detected LanguageEnglish
Typeinfo:eu-repo/semantics/masterThesis
Rightsinfo:eu-repo/semantics/restrictedAccess

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