Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

`Modelling the migration of inorganic contaminants through freshwater systems, validation and sensitivity studies` - FS21103

AEA Technology has developed a modelling methodology to simulate the migration of heavy metals and radionuclides through freshwater systems following deposition onto catchment areas and water bodies. AEA Technology will make a test version of the associated software code (OTTER) available to MAFF. For the code to be of practical use, some additional work is required, including: minor developments to existing code; research to gather relevant physicochemical and other supporting data on heavy metals of interest to MAFF; and validation and sensitivity analysis on the OTTER research code for a range of heavy metals. Four copies of the final version of the OTTER code will be made available to MAFF and the end of the study.
1. CODE DEVELOPMENT - The following developments will be made to code: improvements to the run time; improvements to the general robustness of the code; transfer of the code to a DOS/Windows format with a QuickWin front end. 2. DATABASE DEVELOPMENT - Data will be gathered for a variety of heavy metals to facilitate their modelling by OTTER. Data will be analysed and a relevant OTTER database will then be developed. 3. VALIDATION EXERCISE - The OTTER research code is to be validated by comparison of the model parameters for a range of heavy metals in particular freshwater environments with actual experimental data on contaminant levels gathered for real sites. 4. PARAMETRIC SENSITIVITY ANALYSIS - This analysis aims to identify those input parameters to the OTTER code that appear to be have greatest impact on the results of the modelling. Given the large number of parameters involved in OTTER, this analysis will only consider the dozen or so parameters judged a priori to be important (some sensitivity analysis has already been performed which will inform this decision). This objective will produce a subset of parameters which may be analysed in greater depth in future. 5. PRODUCTION OF REPORT - The results of the validation exercise and parametric sensitivity analysis will be relayed to the MAFF Project Officer via a contract report. 6. DOCUMENTATION - The following documentation will be produced: OTTER User Guide and OTTER Modelling Methodology Report. 7. OTTER PRODUCTION AND HANDOVER - This covers the Quality Assurance aspects of software development, the handover of the code and helpline service from 30 September 1996 to 31 March 1997 (i.e. during use of the test version of the programme).
Time-Scale and Cost
From: 1996

To: 1997

Cost: £40,530
Contractor / Funded Organisations
AEA Technology, Consultancy Services