Page 1© Crown copyright 2004 Meteorological Inputs Groundwater Workshop, Birmingham Murray Dale, 4/11/04

Page 2© Crown copyright 2004 Presentation Content  Rainfall Data  MORECS & MOSES

Page 3© Crown copyright 2004 Rain Gauge Network  Real time Daily  Real time Hourly (1000 planned)  Slow time Daily  Slow time hourly - 200

Page 4© Crown copyright 2004 Quality Control  QA team based in Edinburgh, lead by Ross Melville and Derek Ogle  Brochure available  Conforms to British Standard BS7834 (1996) – Guide to the acquisition and management of meteorological precipitation data (establishing a network, user requirement, siting, data management, QA…)

Page 5© Crown copyright 2004 UK Radar Coverage 1 km coverage (50 km range) 2 km coverage (100 km range) 5 km coverage (250 km range)

Page 6© Crown copyright 2004 Rain gauge location (and 1km storm accumulation) mm

Page 7© Crown copyright km radar accuracy (1 of 3)

Page 8© Crown copyright km radar accuracy (2 of 3)

Page 9© Crown copyright km radar accuracy (3 of 3)

Page 10© Crown copyright 2004 Radar / Gauge data in Urban Drainage Modelling

Page 11© Crown copyright 2004 MORECS

Page 12© Crown copyright 2004 MOSES  Soil Moisture data derived from radar  Advanced scientific representation of processes  5km spatial resolution  Hourly updated  Provides information on soil moisture status

Page 13© Crown copyright 2004 MOSES Soil moisture deficit from MOSES Darcian flow of soil moisture Deep drainage Surface runoff Evaporation from bare soil, trees, grass, crops, wet canopies etc. Rain, Snow Radiation Roots extract water

Page 14© Crown copyright 2004 Moses detail reference on-line  lications/papers/technical_reports/fr.html lications/papers/technical_reports/fr.html  Report # 428

Page 15© Crown copyright 2004 MOSES-PDM – MORECS Inter-comparison  Project jointly funded by the EA and Met Office  Compared two extreme hydrological events  Drought of and floods of  For 4 contrasting MORECS squares  24 month periods investigated  Inter-comparison contrasted with findings from available literature  Study concluded that MOSES-PDM better represents processes of evaporation, drainage and soil moisture than MORECS

Page 16© Crown copyright 2004

Page 17© Crown copyright 2004 VariableDifference from comparison PeriodSupport from literature review? Possible causes PE/AEMX>MSWinterMOSES canopy resistance, soil heat flux Annual√ PEMX>MSVery dry summerMOSES canopy resistance AEMX=0, MS>0Very dry summer√Fixed available water in MORECS, MOSES calculates water transfer in dry soil EPMX>MSAutumn√In MOSES the gradual wetting of the lowest soil layer gives a slower onset of drainage EPMX<MSSummer, annual√MOSES has less AE and also has drainage when SMD>0 SMDMX>MSSpring√MORECS has more AE MOSES / MORECS Comparison Summary

Page 18© Crown copyright 2004 Inter-comparison  MORECS uses the science and concepts of the late 1970s; the update in 1995 introduced more realistic soils data, but did nothing to change the basic science. MOSES includes more recent developments in evaporation and soils modelling including:  Canopy resistance to moisture transfer which interacts with weather  Soil heat flux modelling  Soil moisture movement modelling, snowmelt, surface runoff  5 km soils and land use, but only 1 farm crop type  PDM represents a range of soil properties to represent soil moisture variability and runoff  This report has shown the benefits of these improvements

Page 19© Crown copyright 2004 Summary  Raingauge network details, planned real-time gauge increase, QC obligations  Radar – more appropriate for spatial rainfall than point source data (gauges)  MORECS – 1970s model, modifications in 1990s  MOSES – higher resolution (time and space), better representation of reality