Centre for Earth Systems Engineering Research

Broad Scale Urban Flood Risk Analysis

Broad Scale Urban Flood Risk Analysis

Development of a broad scale urban flood risk analysis for climate impacts and adaptation.

Introduction

The consideration of climate change in the development of sustainable cities is important. The interaction between these two areas has received far too little attention. 

To the date there has not been a quantitative assessment of the adaptation measures that could be implemented to make cities more sustainable. 

The results of this evaluation will provide essential information for:

  • urban planners
  • engineers
  • policy-makers

It will help to create plans, designs and strategies to reduce GHG emissions and to adapt urban areas to future climate change.

Aims

The author is expected to provide an answer to the following research needs:

Integrating climate change when evaluating adaptation measures

For this, an improved urban rainfall model disaggregation needs to be obtained. A series of climate change scenarios exist, but they have not been used in testing how the urban environment will behave if any of them were to occur in the future. 

Evaluating real case studies

There is the need to evaluate real case studies. Impacts of climate change can be evaluated and the level of current resilience on cities can be obtained. 

Areas to model include: 

  • the town of Morpeth
  • the city of Newcastle
  • the city of Barcelona
  • the megacity of London

Methodology

Climate change scenarios, adaptation measures and topographic data will be used as input for the model. 

The outputs from the model will help decision makers to:

  • take actions
  • create flood management plans
  • evaluate the effectiveness of adaptation measures

CityCat

CityCat (City Catchment Analysis Tool) is a novel and unique software tool. It's used for modeling, analysis and visualisation of urban surface water flooding and flood alleviation. 

CityCat is a project funded by the Environment Agency’s Local Levy. This was raised by the Northumbria Regional Flood Defense Committee. It was based on an existing state-of-the-art 2D hydrodynamic model NOAH 2D developed at Newcastle University.

CityCat has been previously set up and simulations have been performed for a citycentre application in Newcastle upon Tyne. 

A design storm was input to re-create a pluvial flood event. Interventions such as water storage on buildings and flow barriers were tested.

More recently, CityCat has been used to model a tidal surge of the Thames river.

Software development

One of the main objectives of this research is to be able to model sustainable drainage measures. This needs to be incorporated in the CityCat software. 

The CityCat is a program written in Delphi language. Code to model blue roofs (water storage roofs) and green roofs can be added. This is for the modelling of adaptation measures and is being developed as part of this research. 

The program created is able to model water roof storage in buildings according to a rainstorm events. This able to specify a number of different parameters, from the number of pipes used for drainage to the height of the roof wall. 

The solution is obtained using Runge Kutta 3rd order. The code for the green roof is being developed with similar capabilities for the user. In this case Green-Ampt equations are used in the model.

References

 IPCC. (2007). Climate Change 2007: Synthesis Report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change In T. C. W. Team, R. K. Pachauri & A. Reisinger

Glenis, V., Kilsby, C., Kutija, V. & Quinn, P. (2010). CityCat Urban flood modeling and analysis software report (C. E. a. Geosciences, Trans.) (pp. 1-19): Newcastle University.

Walsh, C. L., Batty, M., Zanni, A. M., Barr, S. L., Carney, S., Bristow, A. L., Dawson, R. J. (2011). Assessment of climate change mitigation and adaptation in cities. Proceedings of the ICE - Urban Design and Planning, 164(2), 75-84. doi: 10.1680/udap.