Changes in urbanisation and its effects on water quantity and quality from local to regional scale

Lead Research Organisation: University of Surrey
Department Name: Civil and Environmental Engineering


Over the past 50 years changes in UK land-use have been considerable and substantial change is likely to continue. The UK population is projected to increase by 16% to 2035 which will bring about change to the size and structure of urban areas and increased pressure on land management, especially in the south-east. This project, by calling upon a range of tested modelling approaches and associated expertise will advance understanding of the fine-scale impacts of urbanisation on water resources and pollution, which are currently poorly understood. The focus will be on water security in the Thames river basin where projections of future population and climate indicate serious water stress. Detailed case studies at a local scale (including Bracknell and Swindon), where the impacts of past land-use changes on river hydrological and ecological regimes are likely to be large, will be undertaken and a novel integrated modelling approach developed and tested. The approach will then be rationalised and up-scaled for testing across the entire Thames, and, in conjunction with projections of urban development and land management change, used to quantify future effects. These findings will be set in the context of effects indicated to be a direct consequence of climate drivers.

Planned Impact

Outputs from the research are expected to bring benefits to stakeholders across multiple sectors as follows.

(i) Water managers: The results from the research will provide water managers, primarily the Environment Agency, Thames Water and the Rivers Trust, with a holistic assessment of the contribution of point source pollution from expanding population centres, and their relative importance compared to other pollution sources and climate change impacts. This information is important for defining strategies for reducing pollution and achieving good ecological status.

(ii) Local authorities: The growth of population centres is determined by planning decisions made at a local level. The output from the project will enable local governments and spatial planners to better understand the links between local growth strategies and the resulting impacts on the receiving waters, both locally and on the scale of the Thames basin. The research will also provide local authorities with information on the effectiveness of local water management strategies such as Sustainable Urban Drainage Systems.

(iii) Business community: This project is aimed at local planning so direct engagement will be with the local authorities. Most businesses will be interested indirectly and will get information through local authority channels. However we will use a number of existing knowledge exchange channels to engage with the wider business community.

(iv) Non-governmental organisations: The Thames River is used by a plethora of people and organisations for recreational (e.g. boating and fishing) and wildlife conservation. Examples include the Inland Water Association, Thames Anglers' Conservancy, and the Thames River Restoration Trust. All of these organisations have an interest in a reduction in pollution in the Thames River and the output of the research will assist these NGOs to use their limited resources where they are most likely to have a positive impact and as part of their educational material.

To best engage with a wide range of stakeholders we will put our findings in the context of provision of ecosystem services and how the sustainability of this provision may be affected by future change, both in urbanisation and as a result of climate. We will communicate project results to a topic group outlining the premise behind ecosystems services (that they represent the benefits in terms of monetary value that people receive from nature). The topic group will meet three times during the project and include representatives from organisations in all four sectors outlined above.

A proposed secondment of a CEH research scientist to work in Defra for a 20 day period, will not only allow policy makers to get involved in the interpretation of results but also to ensure our research outcomes directly inform their initiatives. Building on our existing collaborative links, research scientists will organise meetings in Parliamentary Office of Science and Technology to raise awareness of the research and gain feedback.

We have been successful in setting up a private sector partnership with the Earthwatch organisation who will contribute co-funding from a worldwide HSBC initiative. Manpower will also be provided by HSBC, in the form of "citizen scientists" who will be trained to participate in scientific data collection and thereby directly contribute to our project. Therefore, this will potentially be very influential, and with the help of Earthwatch, create very effective media for disseminating project findings in a wider context to a diverse range of beneficiaries. Sustaining the research and its influence beyond the lifetime of the project is important and we will probably seek to do this through a Knowledge Transfer Partnership with a business partner.
Description This project has analysed past patterns of urban growth over the last 4 decades,using UK Census data as well as satellite based land cover maps developed by our project partners. The analysis has revealed that at a regional scale spatial planning policies have a substantial impact. In particular the protected status of green belts makes explains spatial disparities, whereas over time a changing balance between urban expansion and densification of existing urban areas governs urban outcomes, and in turn the hydrological response.

Our analysis of high-resolution monitoring of flows and water quality during the Winter of 2013/2014 across a rural to urban boundary has given us further insight in the relationship between urban activities and urban hydrology. A number of processes and mechanisms are at play and can be recognized in the data, regarding to the timing and location of storm events. We found that the most significant and lasting impact was the potential issue of waste water treatment capacity and the possible discharge of untreated effluent during large storm events.
Exploitation Route Based on our findings of urban growth patterns, we believe there would be an interest in deeper analysis of urban change processes within existing urban areas and its impact on urban hydrology. This would be a break from existing studies focusing on urban extent only and require an analysis at finer spatial scales than deployed.

Our analysis of the impact of storm events along the urban-rural gradient raised significant issues. Further research should explore how these interactions between water treatment capacity, meteorology and urban hydrology are different in summer. Also findings provide priorities for further research into the impact of urban change processes on water quality.
Sectors Communities and Social Services/Policy,Environment,Government, Democracy and Justice

Description Data and tools from the project have been used for teaching materials and MSc dissertations at the University of Surrey. Other impacts are reported separately by the other projects in this joint project.
Sector Education
Impact Types Societal

Description PhD Project in NERC SCENARIO DTP
Amount £54,756 (GBP)
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 09/2017 
End 09/2020
Title Water quality in Swindon and Bracknell 
Description This database contains water quality measurement from 6 sondes in the areas of Bracknell and Swindon, over the period of December 2013 - January 2014. The data covers a period of intense storms. The sondes capture: turbidity, pH, temperature, ammonium (and battery status) 
Type Of Material Database/Collection of data 
Year Produced 2014 
Provided To Others? Yes  
Impact This data was instrumental in our analysis of the impact of storm on water quality in a variety of urban settings. 
Description The Constrained Cellular Automata model used for urban change analysis and forecasting 
Type Of Technology Software 
Year Produced 2016 
Open Source License? Yes  
Impact The software has been used for MSc dissertation projects, but has not yet found a wider audience. It is shared due to our commitment ot Open Source. Further documentation efforts are required to enhance the impact in the scientific community. 
Title Software library for analysis of raster based geographical information 
Description This software library makes it possible to efficiently access and analyze raster based geographical information using modern (C++11) programming techniques. It is a foundation to the further libraries for Map Algebra (open source), Cellular Automata land use modelling (open source) and Moving Window analysis (open source). 
Type Of Technology Software 
Year Produced 2015 
Open Source License? Yes  
Impact The open source library is available on Github and has been shared with academic collaborators. It is still too early to see a notable impact in their work. 
Title Software library for generalized moving window based analysis on raster datasets 
Description A software library that supports generalized techniques for scale-dependent analysis of raster data through the application of moving windows. The library is a core component of the Map Algebra and Cellular Automata land use model libraries that we are using for the urban change analysis. 
Type Of Technology Software 
Year Produced 2015 
Open Source License? Yes  
Impact It is still too early to see an impact, but a publication on the methods of this library has been favorably reviewed and published in a high impact (IF 3) journal on earth observation and geoinformation. 
Description Royal Society MP Pairing Scheme (by Dr Scott McGrane) 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Each year 30 research scientists are paired with UK parliamentarians and civil servants. They learn about each other's work by spending time together in Westminster and the researcher's institutions. Dr McGrane spent a week in Westminster, learning about the science/policy interface whilst shadowing an MP, the Rt. Hon Anne Milton (Conservative MP for Guildford). A return visit by Anne Milton is still forthcoming.
Year(s) Of Engagement Activity 2015