Soil Carbon Fluxes due to Water Erosion at the Global Scale
Abstract
Soil erosion by rainfall is currently accelerated globally by human activities, such as deforestation and agricultural practices. Accelerated soil erosion can trigger large sediment fluxes between land and ocean. In this way accelerated soil erosion can alter carbon dynamics on land and in the ocean. These anthropogenic modifications to the carbon cycle are largely unknown at the global scale. It is, therefore, important to study the interaction between sediment dynamics and the global carbon cycle at large spatial scales. In this study we aim to estimate the lateral transport of soil carbon due to water erosion and consequent land-atmosphere CO2 fluxes on the global scale. For this purpose we couple an existing spatially explicit large-scale model on soil erosion and sediment fluxes with the carbon emulator from the land surface model ORCHIDEE. The carbon emulator describes the carbon fluxes and pools exactly as in the simulations with the full ORCHIDEE model. In addition to the existing soil carbon processes of the model we introduce carbon erosion, deposition and transport. We also differentiate between carbon dynamics on hillslopes and in floodplains of a landscape. With this dynamical modeling approach we present global estimates of present-day changes in soil carbon storage due to soil erosion. We also introduce and discuss the first steps of including sediment dynamics in a land surface model to estimate the effects on the carbon cycle.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.B31L..02N
- Keywords:
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- 0428 Carbon cycling;
- BIOGEOSCIENCESDE: 0486 Soils/pedology;
- BIOGEOSCIENCESDE: 1630 Impacts of global change;
- GLOBAL CHANGE