|137Cs as radiotracer: can be utilized for the assessment of erosion and sedimentation|
|Total 137Cs inventory: quantitative models on arable lands, semi-quantitative estimations on uncultivated lands|
|Point-to-point 137Cs depth profile analysis: erosion and accumulation patterns can be reconstructed on uncultivated lands too|
Radiotracers – gamma-ray emitting radionuclides with high affinity to soil and sedimentparticles – are routinely utilized for the assessment of erosion and sedimentation. Techniquesbased on fallout-derived 137Cs (radiocaesium) are being developed from the late 60s for bothcultivated and uncultivated lands. These techniques possess many advantages compared totraditional ones: they can reconstruct the pattern of the erosion and accumulation of the pastfour decades based on the results of a single-time sampling.
For the basic utilization of this method, one has to determine the total 137Cs inventory (in Bq/m2) in the soil column at the points of interest and compare them to the area-specific reference inventory. On arable land (where the traceris more or less uniformly distributed in the ploughed layer) this information is adequate for theaccurate calculation of soil loss and redistribution using advanced mass-balance models. Onuncultivated lands, however, one has to determine not only the inventory but the depth profile of 137Cs as well. From a point-to-point 137Cs depth profile analysis one can reconstruct erosion and accumulation patterns on uncultivated lands too.