Model
SEPARATE (SEctor Pollutant AppoRtionment for the AquaTic Environment)

National scale nutrient and sediment source apportionment screening tool for England and Wales developed originally as part of Defra project WQ0223 (Developing a field toolkit for ecological targeting of agricultural diffuse pollution mitigation measures). SEPARATE provides apportionment of annual loads of nitrogen, phosphorus and fine-grained sediment, from both diffuse (agriculture, urban, river channel banks, atmospheric deposition, groundwater) and point (sewage treatment works, septic tanks, combined sewer overflows, storm tanks) sources to rivers at Water Framework Directive waterbody scale. The data cover individual and accumulated waterbodies.

Version
2.0
Contact
Professor Adie Collins, Rothamsted Research; Dr Dave Skirvin, RSK ADAS, Rothamsted Research; RSK ADAS
Keywords
Release Date
2014
License
OGL
Operating Requirements
GIS for data mapping
Application Type
EXCEL spreadsheet
User Interface
Spreadsheet, GIS
Support Available
Limited support from developers
Application Scale
national
Geographical Restrictions
UK
Temporal Resolution
Annual (varying reference years for the different pollutant sources included – e.g. 2010 for agriculture and 2010-2012 for sewage treatment works
Spatial Resolution
WFD cycle II waterbodies across England and Wales – individual and accumulated
Primary Purpose
Nutrient and sediment source apportionment
Key Output Variables
Total nitrogen, total phosphorus, dissolved phosphorus and fine-grained sediment source apportionment by WFD cycle II individual or accumulated waterbodies
Model Structure
A mix of process-based (e.g. PSYCHIC, NEAP-N for agricultural P and sediment, nitrate) modelling and empirical data (e.g. for sewage treatment work discharges)
Model Parameterisation
N/A
Input Data Available on CaMMP Catalogue
N/A
Documentation

Key References

  • Zhang, Y.; Collins, A.L.; Murdoch, N.; Lee, D.; Naden, P.S. (2014) Cross sector contributions to river pollution in England and Wales: Updating waterbody scale information to support policy delivery for the Water Framework Directive. Environmental Science & Policy, 42, pp 16-32. doi:10.1016/j.envsci.2014.04.010
  • Collins, A.L., Anthony, S.G. 2008. Assessing the likelihood of catchments across England and Wales meeting ‘good ecological status’ due to sediment contributions from agricultural sources. Environmental Science and Policy 11, 163-170.
  • Collins, A.L., Anthony, S.G., Hawley, J., Turner, T. 2009a. The potential impact of projected change in farming by 2015 on the importance of the agricultural sector as a sediment source in England and Wales. Catena 79, 243-250
  • Collins, A.L., Anthony, S.G., Hawley, J., Turner, T. 2009b. Predicting potential change in agricultural sediment inputs to rivers across England and Wales by 2015. Marine and Freshwater Research 60, 626-637.
  • Davison, P.S., Withers, P.J.A., Lord, E.I., Betson, M.J., Stromqvist, J. 2008. PSYCHIC - a process-based model of phosphorus and sediment mobilisation and delivery within agricultural catchments. Part 1: model description and parameterisation. Journal of Hydrology 350, 290-302.

Input Data

  • Data included in model spreadsheet

Output Data

  • Total N annual source apportionment for agriculture, urban, channel banks, atmospheric deposition to water, sewage treatment works, septic tanks, combined sewer overflows, storm tanks, groundwater
  • Total P annual source apportionment for agriculture, urban, channel banks, atmospheric deposition to water, sewage treatment works, septic tanks, combined sewer overflows, storm tanks, groundwater
  • Dissolved P annual source apportionment for agriculture, urban, sewage treatment works, septic tanks, combined sewer overflows, storm tanks, groundwater
  • Sediment annual source apportionment for agriculture, urban, channel banks, sewage treatment works

Quality Assurance

Developer Testing
Yes
Internal Peer Review
Yes
External Peer Review
Yes
Use of Version Control
Yes
Internal Model Audit
Unknown
External Model Audit
Unknown
Quality Assurance Guidelines and Checklists
Unknown
Governance
Unknown
Transparency
Unknown
Periodic Review
Yes