Comparing measurements, ⁷Be radiotracer technique and process-based erosion model for estimating short-term soil loss from cultivated land in Northern Germany

Abstract

Deumlich D., Jha A., Kirchner G. (2017): Comparing measurements,7 Be radiotracer technique and process-based erosion model for estimating short-term soil loss from cultivated land in Northern Germany. Soil & Water Res., 12: 177−186.Due to changing climate and irregular weather patterns, event-based soil loss and sediment yield have become important issues in the agricultural areas. Several mathematical models and prediction methodologies have been used to estimate event-based soil loss and soil redistribution based on soil types, land management, hydrology and local topography. The use of short-lived beryllium-7 as a means of estimating event-based soil erosion/deposition rates has become an alternative to the traditional soil loss measurement methods. A new erosion model taking into account the movement of 7 Be in soils has been presented recently. In order to direct the attention to the potential offered by this technique (measurements and mathematical model), a two-year study was performed at the erosion plots in Müncheberg, Germany, and twelve individual erosion rates were estimated. This paper presents a systematic comparison of the non-steady state 7 Be model with the process-based erosion model EROSION-3Dand measured data. The results demonstrate a close consistency between the erosion rates estimated by erosion models and the estimates provided by the 7 Be model and can therefore be seen as a promising contribution to validating the use of this radionuclide to document short-term soil redistribution within the plot and deposited sediment at the bottom of the plot.

Influence of DEM resolution on modelling hydrological connectivity in a complex agricultural catchment with woody crops

“…These authors found the IC increased for a given pixel when the pixel size decreased. After value normalisation, our results agreed with those of Cantreul et al for DEM resolutions from 1 to 0.2 m, and disagreed over a range of 0.2 to 0.05 m. However, the IC values at the outlet concurred with other hydrological connectivity and soil erosion modelling studies: (i) Habtezion et al (2016) examined the effects of nine DEM resolutions on watershed hydrologic modelling, from 0.02 to 0.8 m, in a small experimental field plot and observed that lower DEM resolutions tended to eliminate topographic features and thus surface depression storage was less represented; this leads to an overestimation of hydrological connectivity; and (ii) Deumlich et al (2017), using the EROSION-3D model in two cultivated plots, predicted decreasing median values of soil erosion with increasing resolution (25, 10, 5, 2 and 1 m). The actual width of some microtopographic connections (rills and ephemeral gullies), which is similar to cell size (from rills a few centimetres wide to ephemeral gullies with a width of 20 to 30 cm), may explain our results and how they compare to other studies.…”

Understanding the role of water and tillage erosion from <sup>239+240</sup>Pu tracer measurements using inverse modelling

“…In the Parisian Basin of France, Chartin et al (2013) demonstrated the dominating role of tillage erosion. Particularly areas of a hummocky topography with short summit-footslope distances, such as young morainic areas, can be subject to pronounced in-field soil degradation patterns caused by tillage erosion (Winnige, 2004;Deumlich et al, 2017). Young morainic areas that are under intense arable cultivation and associated tillage erosion are widespread in northern Europe, Canada, the northern USA, Russia and eastern Argentina.…”

“…Especially anthropogenic radionuclides (e.g. 137 Cs, 239+240 Pu, 210 Pb, 7 Be) have demonstrated their ability to determine changes in topography (Mabit et al, 2014;Alewell et al, 2017;Deumlich et al, 2017). The force of atmospheric nuclear weapon tests transported radioisotopes outside the troposphere, where circulation led to a (regionally) homogeneous spatial distribution and subsequent fallout on soils via precipitation (Meusburger et al, 2016).…”

Understanding the role of water and tillage erosion from <sup>239+240</sup>Pu tracer measurements using inverse modelling

“…Van pointed out that tillage erosion rates are globally at least in the same order of magnitude as water erosion rates. Particularly areas of a hilly topography with short summit-footslope distances, such as young morainic areas, can be subject to pronounced in-field soil degradation patterns caused by tillage erosion (Winnige, 2004;Deumlich et al, 2017). Young morainic areas that are under intense arable cultivation and corresponding tillage erosion are widespread in northern Europe, Canada, northern USA, Russia and eastern Argentina.…”

“…Especially anthropogenic radionuclides (e.g. 137 Cs, 239+240 Pu, 210 Pb, 7 Be) have demonstrated their ability to determine changes in topography (Parsons and Foster, 2011;Alewell et al, 2017;Deumlich et al, 2017). Nuclear weapon tests lifted radioisotopes up to the stratosphere, where mixture led to an almost homogeneous distribution and corresponding fallout by rain (Alewell et al, 2017).…”