Long-term, process-based, continuous simulations for a small, nested rangeland watershed near Tombstone, AZ (USA): Extending model validity to include soil redistribution

Abstract. Currently, the anthropogenic disturbances to the biogeochemical cycles remain unquantiﬁed due to the poor representation of lateral ﬂuxes of carbon and nutrients in Earth System Models (ESMs) that couple the terrestrial and ocean systems. Soil redistribution plays an important role in the transport of carbon and nutrients between terrestrial ecosystems, however, quantiﬁcation of soil redistribution and its effects on the global biogeochemical cycles is missing. This study aims at developing new tools and methods to represent soil redistribution on a global scale, and contribute to the quantiﬁcation of anthropogenic disturbances to the biogeochemical cycles. We present a new large-scale coarse resolution sediment budget model that is compatible with ESMs. This model can simulate spatial patterns and long-term trends in soil redistribution in ﬂoodplains and on hillslope, resulting from external forces such as climate and land use change. We applied this model on the Rhine catchment using climate and land cover data from the Max Planck Institute Earth System Model (MPI-ESM) for the last millennium (850-2005 AD). Validation is done using observed Holocene sediment storage data and observed scaling relations between sediment storage and catchment area from the Rhine catchment. We found that the model reproduces the spatial distribution of ﬂoodplain sediment storage and the scaling relationships for ﬂoodplains and hillslopes as found in observations. The exponents of the scaling relationships can be modiﬁed by changing the spatial distribution of erosion or by changing the residence time for ﬂoodplains. However, the main feature of the scaling behavior, which is that sediment storage in ﬂoodplains increases stronger with catchment area than sediment stored on hillslopes, is not changed. Based on this we argue that the scaling behavior is an emergent feature of the model and mainly dependent on the underlying topography. Additionally, we identiﬁed that land use change explains most of the temporal variability in sediment storage for the last millennium in the Rhine catchment.

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Simulating long-term soil redistribution generated by different patterns of mouldboard ploughing in landscapes of complex topography

Soil and Tillage Research ◽

10.1016/s0167-1987(03)00042-4 ◽

2003 ◽

Vol 71 (1) ◽

pp. 71-86 ◽

Cited By ~ 38

Author(s):

S De Alba

Keyword(s):

Complex Topography ◽

Soil Redistribution

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Uncertainties of the 137Cs technique for validation of soil redistribution modelling in a semiarid meso-scale watershed

Engenharia Agrícola ◽

10.1590/s0100-69162014000200004 ◽

2014 ◽

Vol 34 (2) ◽

pp. 222-235 ◽

Cited By ~ 2

Author(s):

Pedro H. A. Medeiros ◽

José Carlos de Araújo ◽

Avacir C. Andrello

Keyword(s):

Mathematical Models ◽

Model Performance ◽

Sediment Fluxes ◽

Soil Redistribution ◽

Brazilian Semiarid ◽

137Cs Technique ◽

Definition Of ◽

High Uncertainty ◽

Good Agreement

Scarcity of long-term series of sediment-related variables has led watershed managers to apply mathematical models to simulate sediment fluxes. Due to the high efforts for installation and maintenance of sedimentological gauges, tracers have been pointed out as an alternative to validate soil redistribution modelling. In this study, the 137Cs technique was used to assess the WASA-SED model performance at the Benguê watershed (933 km²), in the Brazilian semiarid. Qualitatively, good agreement was found among the 137Cs technique and the WASA-SED model results. Nonetheless, quantitatively great differences, up to two orders of magnitude, were found between the two methods. Among the uncertainties inherent to the 137Cs technique, definition of the reference inventory seems to be a major source of imprecision. In addition, estimations of water and sediment fluxes with mathematical models usually also present high uncertainty, contributing to the quantitative differences of the soil redistribution estimates with the two methods.

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The use of magnetic susceptibility to measure long-term soil redistribution

CATENA ◽

10.1016/s0341-8162(97)00051-9 ◽

1998 ◽

Vol 32 (1) ◽

pp. 23-35 ◽

Cited By ~ 54

Author(s):

E de Jong ◽

P.A Nestor ◽

D.J Pennock

Keyword(s):

Magnetic Susceptibility ◽

Soil Redistribution

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Assessing soil redistribution of forest and cropland sites in wet tropical Africa using <sup>239+240</sup>Pufallout radionuclides

SOIL ◽

10.5194/soil-7-399-2021 ◽

2021 ◽

Vol 7 (2) ◽

pp. 399-414

Author(s):

Florian Wilken ◽

Peter Fiener ◽

Michael Ketterer ◽

Katrin Meusburger ◽

Daniel Iragi Muhindo ◽

...

Keyword(s):

Soil Erosion ◽

Arable Land ◽

Tropical Africa ◽

Tropical Regions ◽

Soil Redistribution ◽

Fallout Radionuclides ◽

Forest Sites ◽

Degradation Rates ◽

Topographic Gradients

Abstract. Due to the rapidly growing population in tropical Africa, a substantial rise in food demand is predicted in upcoming decades, which will result in higher pressure on soil resources. However, there is limited knowledge on soil redistribution dynamics following land conversion into arable land in tropical Africa that is partly caused by infrastructure limitations for long-term landscape-scale monitoring. In this study, fallout radionuclides 239+240Pu are used to assess soil redistribution along topographic gradients at two cropland sites and at three nearby pristine forest sites located in the DR Congo, Uganda and Rwanda. In the study area, a 239+240Pu baseline inventory is found that is higher than typically expected for tropical regions (mean forest inventory 41 Bq m−2). Pristine forests show no indication of soil redistribution based on 239+240Pu along topographical gradients. In contrast, soil erosion and sedimentation on cropland reached up to 37 cm (81 Mg ha−1 yr−1) and 40 cm (87 Mg ha−1 yr−1) within the last 55 years, respectively. Cropland sites show high intra-slope variability with locations showing severe soil erosion located in direct proximity to sedimentation sites. This study shows the applicability of a valuable method to assess tropical soil redistribution and provides insight into soil degradation rates and patterns in one of the most socio-economically and ecologically vulnerable regions of the world.

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Long‐Term Soil Redistribution in a Small French Watershed as Estimated from Cesium‐137 Data

Journal of Environmental Quality ◽

10.2134/jeq1998.00472425002700050024x ◽

1998 ◽

Vol 27 (5) ◽

pp. 1178-1183 ◽

Cited By ~ 21

Author(s):

Claude Bernard ◽

Lionel Mabit ◽

Stanislas Wicherek ◽

Marc R. Laverdière

Keyword(s):

Soil Redistribution ◽

Cesium 137

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Assessing soil erosion of forest and cropland sites in wet tropical Africa using <sup>239+240</sup>Pu fallout radionuclides

10.5194/soil-2020-95 ◽

2020 ◽

Author(s):

Florian Wilken ◽

Peter Fiener ◽

Michael Ketterer ◽

Katrin Meusburger ◽

Daniel Iragi Muhindo ◽

...

Keyword(s):

Soil Erosion ◽

Arable Land ◽

Tropical Africa ◽

Local Conditions ◽

Soil Redistribution ◽

Fallout Radionuclides ◽

Forest Sites ◽

Degradation Rates ◽

Topographic Gradients

Abstract. Due to the rapidly growing population in tropical Africa, a substantial rise in food demand is predicted in upcoming decades, which will result in higher pressure on soil resources. However, there is limited knowledge on soil redistribution dynamics following land conversion to arable land in tropical Africa that is partly caused by challenging local conditions for long-term landscape scale monitoring. In this study, fallout radionuclides 239+240Pu are used to assess soil redistribution along topographic gradients at two cropland sites and at three nearby pristine forest sites located in the DR Congo, Uganda and Rwanda. In the study area, a relatively high 239+240Pu baseline inventory is found (mean forest inventory 41 Bq m−2). Pristine forests show no indication for soil redistribution based on 239+240Pu along topographical gradients. In contrast, soil erosion and sedimentation on cropland reached up to 37 and 40 cm within the last 55 years, respectively. Cropland sites show high intra-slope variability with locations showing severe soil erosion located in direct proximity to sedimentation sites. This study shows the applicability of a valuable method to assess tropical soil redistribution and provides insight on soil degradation rates and patterns in one of the most vulnerable regions of the World.

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