HR: 16:40h
AN: H44B-03    [Abstracts]
TI: Modelling regional patterns of water quality for semi-arid areas
AU: Irvine, B J
EM: b.j.irvine@leeds.ac.uk
AU: * Kirkby, M J
EM: m.j.kirkby@leeds.ac.uk
AF: School of Geography, University of Leeds Woodhouse Lane, Leeds, LS2 9JT United Kingdom
AU: Chapman, P J
EM: p.j.chapman@leeds.ac.uk
AB: Semi-arid areas are prone to high spatial and temporal variability in storm rainfall, with further irrigation pressure on water resources in many areas; water, sediment and solute discharges may decrease downslope and downstream (dQ/dA < 0), resulting in sediment and nutrient deposition on the hillslope and within the stream bed. In the extreme, where flow is lost completely, all material is deposited, to be re-mobilised during subsequent seasonal floods resulting in high sediment and nutrient fluxes. The simplified physical approach of the PESCAS model offers spatial and seasonal estimates of runoff, erosion risk and potential nutrient load respectively from the land, based on the Pan-European Soil Erosion Risk Assessment model (PESERA). Water, sediment and nutrients from the land-phase are delivered downstream based on event magnitude, seasonal probabilities of continuous flow downstream and valley floor morphology. As land use and climate are explicit within the PESERA model, scenarios can be explored. This approach offers a methodology for long term management of water quality, focusing on spatial and seasonal differences, not intra-event dynamics. This approach is less demanding in computing resources than a continuous time model running through each event. By providing estimates of long term seasonal average rates for the many areas which lack data at high spatial and temporal resolution, PESCAS can be used as a tool for planning sustainable management strategies at regional scales.
DE: 1880 Water management (6334)
SC: Hydrology [H]
MN: Fall Meeting 2005