Surface and Subsurface Hydrology

Driving land surface models with high-resolution meteorological data provides analyses and forecasts of surface and subsurface hydrological quantities such as soil moisture, snowmelt, evaporation, runoff and river flow.

MOSES has been enhanced by including a surface runoff production component (the PDM developed at CEH) which represents the heterogeneity of soil water holding capacity. MOSES-PDM has been integrated into the UKPP  system, thereby enabling MOSES-PDM to operate on a 2km grid covering the UK driven by analyses of precipitation, cloud and near-surface temperature, humidity and wind. The system provides hourly updates of the surface and subsurface hydrology. The figure shows an example of the surface runoff produced by UKPP-MOSES-PDM. A prototype river flow model has been coupled to MOSES-PDM. This implementation is a result of further collaboration with CEH hydrologists. CEH have also derived for the Met Office river flow paths and other ancillary files (such as estimates of bank-full flows) for areas of current military deployment and these are being implemented with the RFM coupled to the South Asian CAM run by the Met Office to aid military assessments of trafficability. Further work will enable river flow forecasts to be made for the UK driven by operational ensemble precipitation forecasts.

Keys Aims:

  • To provide high-resolution hourly analyses of soil moisture, snowmelt, evaporation and runoff for use by external customers such as the Environment Agency and for initialising high-resolution NWP models covering the UK.
  • To incorporate the best available soil, land surface cover and terrain height data into the model's ancillary fields. 
  • To improve the accuracy of the precipitation analyses used to drive UKPP-MOSES-PDM by merging radar and real-time rain gauge data. 
  • To provide estimates of soil strength, river flow and flooding for the military to inform judgements about terrain 'trafficability'. 
  • To provide customers who require long period (~30 years or greater) estimates of evaporation, runoff and soil moisture with data from MOSES-PDM driven by the same meteorological data as the long-established MORECS.

Current Projects:

  • Evaluation and implementation of soil property ancillary fields in UKPP-MOSES-PDM derived from the HWSD.
  • Development, evaluation and operational use of merged radar/gauge precipitation analyses to drive UKPP-MOSES-PDM. 
  • Evaluation of river flows from the RFM coupled to the South Asian CAM
  • Development of a plan to integrate or replace UKPP-MOSES-PDM with a stand-alone land surface data assimilation model which additionally makes use of remotely sensed vegetation parameters and cover, lying snow amount and cover, and soil moisture content.

Last updated: 4 September 2014