A coupled soilscape–landform evolution model: model formulation and initial results
<p>This paper describes the coupling of the State Space Soil Production and Assessment Model (SSSPAM) soilscape evolution model with a landform evolution model to integrate soil profile dynamics and landform evolution. SSSPAM is a computationally efficient soil evolution model which was formul...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-06-01
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| Series: | Earth Surface Dynamics |
| Online Access: | https://www.earth-surf-dynam.net/7/591/2019/esurf-7-591-2019.pdf |
| Summary: | <p>This paper describes the coupling of the State Space Soil Production and
Assessment Model (SSSPAM) soilscape evolution model with a landform
evolution model to integrate soil profile dynamics and landform evolution.
SSSPAM is a computationally efficient soil evolution model which was
formulated by generalising the mARM3D modelling framework to further explore
the soil profile self-organisation in space and time, as well as its dynamic
evolution. The landform evolution was integrated into SSSPAM by
incorporating the processes of deposition and elevation changes resulting
from erosion and deposition. The complexities of the physically based
process equations were simplified by introducing a state-space matrix
methodology that allows efficient simulation of mechanistically linked
landscape and pedogenesis processes for catena spatial scales. SSSPAM
explicitly describes the particle size grading of the entire soil profile at
different soil depths, tracks the sediment grading of the flow, and
calculates the elevation difference caused by erosion and deposition at
every point in the soilscape at each time step. The landform evolution model
allows the landform to change in response to (1) erosion and deposition and
(2) spatial organisation of the co-evolving soils. This allows comprehensive
analysis of soil landform interactions and soil self-organisation. SSSPAM
simulates fluvial erosion, armouring, physical weathering, and sediment
deposition. The modular nature of the SSSPAM framework allows the integration of
other pedogenesis processes to be easily incorporated. This paper presents
the initial results of soil profile evolution on a dynamic landform. These
simulations were carried out on a simple linear hillslope to understand the
relationships between soil characteristics and the geomorphic attributes
(e.g. slope, area). Process interactions which lead to such relationships
were also identified. The influence of the depth-dependent weathering
function on soilscape and landform evolution was also explored. These
simulations show that the balance between erosion rate and sediment load in
the flow accounts for the variability in spatial soil characteristics while
the depth-dependent weathering function has a major influence on soil
formation and landform evolution. The results demonstrate the ability of
SSSPAM to explore hillslope- and catchment-scale soil and landscape evolution
in a coupled framework.</p> |
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| ISSN: | 2196-6311 2196-632X |