HR: 17:30h
AN: H54D-07    [Abstracts]
TI: Uncertainties in modelling sediment and phosphorus transfers from intensive, temperate grassland plots
AU: * Krueger, T
EM: t.krueger@lancaster.ac.uk
AF: Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, United Kingdom
AU: Freer, J
AF: Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, United Kingdom
AU: Quinton, J N
AF: Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, United Kingdom
AU: Macleod, C J
AF: Cross Institute Programme for Sustainable Soil Function (SoilCIP), Institute of Grassland and Environmental Research (IGER), North Wyke Research Station, Okehampton, Devon, EX20 2SB, United Kingdom
AU: Bilotta, G S
AF: Cross Institute Programme for Sustainable Soil Function (SoilCIP), Institute of Grassland and Environmental Research (IGER), North Wyke Research Station, Okehampton, Devon, EX20 2SB, United Kingdom
AU: Bilotta, G S
AF: Department of Geography, The University of Exeter, Exeter, EX4 4RJ, United Kingdom
AU: Brazier, R E
AF: Department of Geography, The University of Exeter, Exeter, EX4 4RJ, United Kingdom
AU: Butler, P
AF: Cross Institute Programme for Sustainable Soil Function (SoilCIP), Institute of Grassland and Environmental Research (IGER), North Wyke Research Station, Okehampton, Devon, EX20 2SB, United Kingdom
AU: Granger, S
AF: Institute of Grassland and Environmental Research (IGER), North Wyke Research Station, Okehampton, Devon, EX20 2SB, United Kingdom
AU: Haygarth, P M
AF: Cross Institute Programme for Sustainable Soil Function (SoilCIP), Institute of Grassland and Environmental Research (IGER), North Wyke Research Station, Okehampton, Devon, EX20 2SB, United Kingdom
AB: Erosion of sediment and associated phosphorus from intensively managed grassland is a threat to surface water quality~--–~less "spectacular" perhaps than erosion from arable land but nevertheless significant. Modelling erosion and phosphorus transfer in grassland systems poses both old and new challenges. In particular, our ability to both measure relevant parameters and variables in the field and define effectively the information content in our observations limits the development and testing of models. This is coupled to a shift in focus from surface to sub-surface mobilisation and transport of sediment and phosphorus, brought about by the dense vegetation cover in temperate grasslands which restricts surface erosion processes. While fundamental knowledge is emerging on sub-surface sediment dynamics at the soil core scale, there is little evidence on how to utilise this understanding for models at the plot or catchment scale. In this paper, we explore the uncertainties in model structure, parameters and observed data and their impact on understanding sediment and phosphorus processes at the plot scale. We assess competing model hypotheses for hydrology, sediment and phosphorus dynamics within a model learning framework, i.e. with the aim of rejecting specific models (parameters and structures) where possible. We will discuss the difficulties of inferring process mechanisms robustly from the available data. Furthermore, we shall comment on how this impacts on data collection and model development as we move from small spatial scales (1ha plots) with dense temporal sampling schemes to a larger catchment (40ha) with less data relative to the process complexity operating at this scale.
DE: 1815 Erosion
DE: 1847 Modeling
DE: 1871 Surface water quality
DE: 1873 Uncertainty assessment (3275)
SC: Hydrology [H]
MN: 2007 Fall Meeting