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Past Research Projects

1. The Effect of Catchment Characteristics on Sewage Velocity Grading
HEDGES P D and TYACK J N
The aim of this project was to develop a methodology to enable sewage settling velocity grading curves to be determined from the characteristics of the contributing catchment. Achieving this aim involved the development of a column for determining the settling velocity of sewer solids.

Tyack, J.N. (1996), 'The Effect of Catchment Characteristics on Sewage settling Velocity Grading', PhD Thesis, Aston University. 

2. An Investigation of the Relationship Between Chemical Parameters and Sewage Settling Velocity Grading Curves
HEDGES P D and  BECKER F A
If advances are to be made in the design of separation devices, both to meet consent standards and to improve efficiencies, then it will be necessary to move towards more scientific design procedures than the "rule-of-thumb" approach currently employed. The aim of this project was to determine whether the individual chemical constituents of sewage are associated with specific settling velocity fractions, and hence whether grading curves can be used to improve the design of separation devices.

Becker, F.A. (1997), 'Chemical Constituents Associated with Sewage Settling Velocity profiles, PhD Thesis, Aston University.

3. The Use of Remote Sensing for Monitoring Landfill Gas and Leachate within an Urban Environment
HEDGES P D and ELLIS R J
To date the application of Remote Sensing techniques for monitoring landfill sites in urban areas has been confined primarily to the use of conventional aerial photography. This project sought to evaluate the potential of both the high resolution and the range of spectral bands available from the Airborne Thematic Mapper, and the cheaper alternative, airborne videography for this purpose. The intended outcome from this work was the establishment of an economic methodology, using Remote Sensing, which could be employed for rapidly surveying landfill sites within a large urban area.

Ellis, R.J. (1997), 'Evaluation of Remote Sensing for Detection of Landfill gas and Leachate in an Urban Environment', PhD Thesis, Aston University. 

4. Establishment of a Reedbed Within a Created Wetland Nature Reserve
HEDGES P D and FERMOR P M
On site monitoring was used in this research to assist in the devlopment of hydrological guidelines for the design, creation and establishment of virgin wetland habitats with a particular focus on reedbed ecosystems. The guidelines were based on experience gained on the Teeside International Nature Reserve and the Cardiff Bay Environmental Mitigation Measures project.

Fermor, P.M. (1997), 'Establishment of a Reedbed within a Created Surface water Fed wetland Nature Reserve', PhD Thesis, Aston University. 

5. The Ecological Impact of Intermittent Industrial Discharges on Streams
HEDGES P D and PISOLKAR E M
At the time this project commenced, compliance with the UK CIMAH (Control of Industrial Major Accidental Hazard) legislation requires that industry be able to identify the likely impact of an accidental release of a chemical compound to the environment. In order to do this, it is necessary to understand both the environment that may be impacted and the ecotoxicological effect on flora and fauna. The aim of this research proposal was directed towards the achievement of these ends in relation to freshwater streams by contributing to the understanding and prediction of the impact of these discharges on freshwater macroinvertebrates.

Pisolkar, E.M. (1997), 'the Biological Monitoring of Impact and Recovery in Streams Following Pollution Incidents', PhD Thesis, Aston University. 

6. The Integration of GIS and Hydrological Models to Assess the Environmental Impact of Groundwater Pumping 
HEDGES P D and CHARNOCK T
The overall aim of this project was to evaluate the potential for integrating hydrological models with PC based Geographical Information Systems (GIS) for assessing the impact of groundwater pumping on the environment. The project built upon research into the environmental impact of the Shropshire Groundwater Scheme undertaken at Aston during the 1980s. The GIS was successfully interfaced with a groundwater model, but the interface with a crop-soil-water model was less so. The work employed a classified remotely sensed satellite imagery as the land use data source.

Charnock, T.W. (1997), 'GIS Linked Environmental Process Models', PhD Thesis, Aston University.

7. The Integrated Evaluation of Local and National Future Water Resource Needs
HEDGES P D and CARNELL J
  The water industry currently has no consistent or integrated methodology for developing and utilising water resource planning allowances. The inconsistency renders both funding by OFWAT and resource development approval by the NRA cumbersome and time consuming. This project aimed to produce an integrated methodology for the determination of future water resource need. This was achieved by assessing the full potential range of water resource planning needs under the headings of: demand allowances; resource allowances; source yield allowances; operational allowances. Subsequently, the statistical distributions and dependency of each allowance was investigated to determine how best they could be combined together using risk assessment software.

Carnell, J (1999), 'Calculating the Balance Between Water Resources and Water Demands an Approach Using Risk Analysis', PhD Thesis, Aston University. 

8. The Geometric Correction of Airborne Line-Scanner Imagery
HEDGES P D and GREGORY S
It is well recognised that rectification of airborne line-scanner imagery based on the use of polynomial mapping functions does not yield satisfactory results. A methodology has been developed for identifying image disparities resulting from variations in platform attitude by comparing a line-scanned image directly with an aerial photograph of the corresponding region. In the absence of platform ephemeris data this methodology can be utilised to enable multi-temporal data sets to be corrected and registered.

Gregory, S. (2001), 'The Geometric Correction and Registration of Airborne Line-Scanned Imagery for Temporal Thermal Studies', PhD Thesis, Aston University. 

9. Determining the Settling Velocity Profile of Sewer Solids
HEDGES P D
In recent years settling velocity has steadily grown in importance as the parameter best representing the influence of gravity on sewer solids, and a number of research groups have independently developed equipment for measuring this parameter. However, it is clear from a study of the available literature that different terms are employed by researchers to describe various aspects of their work, and their results are presented in a variety of ways. If the outcome of research on the settling velocity of sewer solids is to be of value to other researchers and practitioners working both in the field and in modelling, there is a need for a comparison of these devices so that confusion is avoided and the data collected is portable. This research led to the production of an annex to:

See Appendix to Ashley, RM, Bertrand-Krajewski, JL, Hvitved-Jacobsen T, and Verbank M (ED) (2004), Characteristics, Effects and Control of Sewer Solids and Associated Pollutants, Scientific & Technical Report No 14, International Water Association, IWA Publishing, 324-331.

10. The Water Use Rates of Diverse Habitats in Wetland Systems
HEDGES P D, READ K, AND FERMOR P
To create hydrologically sustainable wetlands, knowledge of the water use requirements of target habitats must be known. Extensive literature reviews highlighted a dearth of water-use data associated with large reedbeds and wet woodland habitats and in response to this field experiments were established.

Field experiments to measure the water use rates of large reedbeds [ET(Reed)] were completed at three sites within the UK. Reference Crop Evapotranspiration [ETo] was calculated and mean monthly crop coefficients [Kc(Reed)] were developed. Kc(Reed) was less than 1 during the growing season (March to September), ranging between 0.22 in March and reaching a peak of 0.98 in June. The developed coefficients compare favourably with published data from other large reedbed systems and support the premise that the water use of large reedbeds is lower than that from small / fringe reedbeds.

A methodology for determining water use rates from wet woodland habitats (UK NVC Code: W6) was developed, in addition to establishing provisional ET(W6) rates for two sites in the UK. Reference Crop Evapotranspiration [ETo] data was used to develop Kc(W6) values which ranged between 0.89 and 1.64 for the period March to September. The data are comparable with relevant published data and show that the water use rates of wet woodland are higher than most other wetland habitats. Initial observations suggest that water use is related to the habitat’s establishment phase and the age and size of the canopy tree species.

A theoretical case study presents crop coefficients associated with wetland habitats and provides an example water budget for the creation of a wetland comprising a mosaic of wetland habitats. The case study shows the critical role that the water use of wetland habitats plays within a water budget.

Read, K. (2003), ‘The Water Use Rates of Diverse Habitats in Wetland Systems’, PhD Thesis, Aston University.

11. Implementing Biodiversity Action Plans Within Environmental Management Systems
HEDGES P D, CALOW J, AND FERMOR P
Thousands of organizations have so far been accredited to Environmental Management Standards such as ISO 14001 and EMAS and yet there are very few examples of biodiversity issues being formally linked to certified Environmental Management Systems (EMS). A review of current literature highlighted a need to develop structured guidance setting out the process organisations must take to formally incorporate Biodiversity Action Plans (BAPs) into their EMSs. In addition, many authors were of the opinion that certification bodies were somewhat lacking in biodiversity expertise, and were therefore not pro-active in appreciating biodiversity opportunities.

The aim of the research project was to develop a methodology to enable companies to establish and implement BAPs within EMS, particularly ISO 14001. Questionnaires were sent to 14 collaborating organisations, to collect information on biodiversity issues associated with each organisation, and the integration of biodiversity issues into key stages of their EMS. This information was then used to produce flow diagrams to illustrate how biodiversity could be incorporated into an EMS, thus delivering a process to conserve and enhance biodiversity in an organisational setting (organisational BAP).

A Biodiversity Benchmark was produced. This is a process, distilled from key elements of best practice at the participating organisations and supplemented by information gathered from workshops and literature sources to develop a biodiversity management process. This allows any organisation that adopts the Benchmark to protect and enhance their biodiversity within a cycle of continuous improvement.

Calow, J. (pending), ‘Implementing Biodiversity Action Plans Within Environmental Management Systems’, PhD Thesis, Aston University.

Employable Graduates; Exploitable Research