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1

Estimation of soil erosion on cultivated fields on the hilly Meghalaya Plateau, North-East India

Poręba G. J., Prokop P.

Geochronometria

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2011

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Vol. 38, no. 1

77-84

EN

The estimation of soil erosion rates in complex subtropical agricultural systems of hilly environment is difficult and most of the traditional methods have serious limitations. The 137Cs technique allows to obtain relatively quickly retrospective medium term soil erosion results. The objective of this study was using 137Cs approach to quantify soil loss under agricultural system which develops under growing human pressure on the hilly terrain of the Meghalaya Plateau. The measured values of caesium inventory for all sampling points are between 2% and 63% of the reference value of caesium inventory. The estimated annual soil loss for sampling points located on the slope are between 29 and 79 Mgźha-1źyr-1 in the case of an improved mass balance model. It means that soil erosion in this manually tilled agricultural area cannot be neglected.

2

Zastosowanie 137Cs do modelowania procesów erozji i akumulacji w obrębie lessowej doliny użytkowanej rolniczo

Poręba G. J.

Landform Analysis

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2008

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Vol. 9

369--372

3

Influence of the parameters of models used to calculate soil erosion based on 137Cs tracer

Poręba G. J., Bluszcz A.

Geochronometria

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2008

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Vol. 32

21-27

EN

Soil erosion is a serious problem especially on arable land in the loess areas of southern Poland. Reliable data of soil erosion are important to propose a proper method of soil conservation. Measurements of 137Cs inventory allow obtaining both long-term mean value of soil erosion and spatial pattern of soil erosion. To obtain quantitative results of soil erosion from 137Cs measurements one of the mathematical models must be used. Currently, there are many such models in circulation and the results of calculations of soil erosion depend not only on the particular model but also on values assumed for parameters of this model. This paper describes some problems related to calculating soil erosion and deposition based on 137Cs data, namely, the influence of additional parameters on calculated soil erosion is considered. In particular, we have considered the influence of values assumed for plough depth, ă factor, particle size correction factor, soil density and the contribution of the post-Chernobyl deposition to the total caesium deposition on the calculated soil erosion values. The calculations of soil erosion have been done for four, most commonly used models, using real caesium inventory data collected by the authors. The influence of errors of model parameters on the results of soil erosion rate estimates is about 1%, or less for 1% relative error in the parameter.

4

The basis of the study of the age of the Holocene diluvium on loess areas of Polish Highlands

Bluszcz A., Poręba G. J., Śnieszko Z.

Geochronometria

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2007

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Vol. 28

61-66

EN

Large part of slope sediments (pediment) which are the effect of water induced soil erosion in the loess areas of Polish Uplands, has a close relationship with pre-historical, historical and "present" agricultural activity. The sediments accumulated in different periods are often separated by fossil soils. These soils are correlated with the periods of relinquishment of agricultural land use in a given area. A precise dating of the cycles of fossil soil formation is practically impossible. Therefore it is important to gain a possibility to establish the age of sediments between old fossil soils corresponding with the phases of soil erosion. The organic material in the floor or roof of deposits permitting a 14C dating is very seldom. This is why attempts were made to use the OSL method to date mineral parts of slope sediments. In connection with pedological and sedimentological methods, the OSL method makes it possible to give some information about the age of pre-historical and historical phases of intensive soil erosion. In order to date sediments accumulated during the last 50 years, the method based on measurement of 137Cs isotope in products of soil erosion is used. This paper shows some examples of the application of 14C, OSL and 137Cs methods in some selected research sites. In each case there is a discussion of limitations of the methods used.

5

Determination of the initial 137Cs fallout on the areas contaminated by Chernobyl fallout

Poręba G. J., Bluszcz A.

Geochronometria

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2007

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Vol. 26

35-38

EN

The fallout radioisotope 137Cs is widely used to study rates and patterns of soil redistribution. This method requires the knowledge about the initial fallout of cesium in the study area. This paper describes the method of establishing the initial fallout of cesium for a study area which is contaminated by Chernobyl fallout. The study was carried out on the loess area near the Ujazd village (South-West Poland). The 137Cs activities for reference soil cores varied from 4.41(24) kBq/m2 to 5.97(26) kBq/m2. The average value of the reference inventory of 137Cs for the study area is 5.23(15) kBq/m2. The calculated contribution of the Chernobyl 137Cs fallout in the total cesium is equal 69 %. Moreover the annual values of the 137Cs fallout based on the precipitation data were calculated and presented. This study provides the method of calculating the 137Cs fallout connected with the nuclear weapon testing based on the precipitation data. Moreover, this study also indicated that the spatial variability on the highly contaminated by Chernobyl cesium study area is small (RSD about 10%) and thus it is possible to use the cesium method to study soil redistribution.

6

Caesium-137 as a soil erosion tracer: a review

Poręba G. J.

Geochronometria

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2006

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Vol. 25

37-46

EN

This paper describes a method of soil erosion and soil movement measurements using 137Cs as a tracer. This technique has been used successfully employed for more than 30 years. Caesium-137 is a valuable tracer to study soil erosion. Its chemical and biological movement in soil is limited. Practically all redeposition of caesium-137 in soil after fallout occurs with soil particles due to strong fixation of caesium onto soil particles. This technique overcomes many problems of the traditional techniques to study soil erosion. First of all, this technique gives quantitative results of soil erosion and deposition for the medium-term (about 40 years). Moreover, these results are possible to obtain in a relatively short time compared to the traditional methods. The 137Cs method to obtain quantitative value of soil erosion and deposition requires the availability of undisturbed sites to obtain the reference value of 137Cs fallout for the study area and a numerical relationship. Currently, there are many calibration relationships available and the calculation of the soil erosion from 137Cs activity data strongly depends on the chosen relationship and the parameters that were used for a particular model.

7

The Influence of cesium activity on the annual dose for OSL dating

Moska P., Poręba G. J., Bluszcz A.

Geochronometria

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2004

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Vol. 23

15-19

EN

Introduction of single aliquot protocols dramatically improved the accuracy of absorbed dose measurements, so now dating of very recent events, which ages are of the order of tens of years or even single years, becomes possible. The overall accuracy of the OSL age is now limited by the correct assignment of the dose rate. Certain types of recent sediments may contain fall-out radioisotopes that increase the average annual dose. In this paper we demonstrate that the contribution from fall-out radioactivity may be significant and the way to take it into account by using a modified age equation.