PhD opportunity at Lancaster University, associated with supervisors from Rivers Trust and JBA Consulting:
"Mitigating Floods with Trees, Soils and Ponds: Closing the Evidence Gap"
Floods have impacted tens of thousands of homes in the UK over the last 10 years. The review of the summer 2007 floods suggested that small-scale interventions, if extensive in the landscape, might help mitigate flood incidence. Government responded within the Flood and Water Management Act (2010) by promoting flood mitigation strategies that make greater use of natural processes within distributed, local interventions. These measures include planting trees (that enhance evaporation and soil infiltration while slowing surface flows), improving the infiltration potential of agricultural soils, blocking rapid drainage channels on slopes and short-term retention of water on slopes or in channels during floods. While each measure has the potential to slow the migration of flood waters through catchments, little experimental evidence is available for the UK to provide the necessary assurance that modelled flood reductions are accurate. While measures of so called ‘natural flood management (NFM)’ are being incorporated into the UK landscape, the landowners and NGOs adding the measures, and the beneficiary communities downstream, are starting to demand clearer evidence of the flood-mitigation benefits locally and much further downstream. We would argue that this requires a sophisticated approach that incorporates in flood simulation models the current uncertainty associated with the magnitude of change in hydrological processes likely with each NFM measure. Additionally, we never have perfect information about the catchments we model, so this uncertainty should be expressed in our modelling too. By adopting this degree of academic openness, we are better equipped to identify what new experimental data would best improve our models of hydrological change resulting from NFM interventions and demonstrate the benefits of additional data to our simulation accuracy.
To deliver the urgent need for stronger evidence of NFM effectiveness to UK and regional government, NGOs and flood-affected communities, alongside scientific advances of international significance, this project is necessarily a blend of field data collection and catchment modelling. The balance between fieldwork and modelling depends on the interests and skills of the researcher appointed. The modelling work will be a nationally unique combination of physically-based whole-catchment modelling, industry-standard surface-water modelling and cutting-edge, data science modelling. The physically-based modelling will utilise and advance the latest version of Dynamic-TOPMODEL (eg Metcalfe, Beven and Freer, 2015 Environ Modell Softw) and benefit from Lancaster’s high-performance computer systems and expert input from Distinguished Prof Keith Beven, the lead developer of TOPMODEL. This model is supported by the use of JBA Consulting’s JFLOW modelling of surface flows, an innovative software package used in many national flood assessments for the Environment Agency (eg Hankin et al 2017 see link below). Detecting change in observed flood characteristics produced by NFM interventions is best achieved with data science models, and Lancaster’s CAPTAIN Toolbox can be used for this aspect of the project (Chappell et al 2017 Environ Modell Softw). The direct field evidence of hydrological manipulations via trees, soils and ponds is sparse for the UK situation. The successful candidate will be involved with the design of new field experiments to deliver data to improve the modelling. These pioneering field measurements conducted by the PhD student, in collaboration with other Lancaster researchers, will cover the effects of trees on soil infiltration and permeability (eg Chandler and Chappell 2008 For Ecol Manage); effects of altered ground conditions on overland flow and soil moisture; and potential for vegetation changes to affect evaporation and soil moisture during flood events. The fieldwork and associated modelling will have a focus on Cumbrian catchments given our partnerships locally and given the proximity of the field sites to Lancaster. Research in other NFM priority basins and experimental basins across the UK might also form a core component of the project. David Johnson of the Rivers Trust (www.theriverstrust.org) will support the stakeholder engagement aspects of the project essential for implementation of field experiments and for delivering findings that can be used by NGOs and government to develop policy and further implementation of NFM nationally.
Full studentships for UK/EU students for 3.5 years or full studentships for International students for 3 years.
Deadline Tuesday February 28th 2017