(For more details, see the Inundation subpages in Menu bar -> Projects -> Inundation)
As part of my work for the NERC project Hydro-JULES and the UK Met Office project UKEP, I am currently working on modifying the JULES River Flow Model (RFM) to include an improved representation of the process of overbank inundation. Without this, modelled water courses in RFM cannot overflow their banks and inundate the surrounding landscape to form fluvial wetlands. Overbank inundation is generally implemented in fine-scale flood prediction models (e.g. CaMa-Flood, LISFLOOD), but is rarely implemented in a robust way in global-scale land surface models. In Hydro-JULES, we are working on a new framework for interactive overbank inundation in JULES. This will not only simulate inundation extent more reliably, but will also characterise feedbacks on ecosystem function in inundated areas, which is currently not represented in any land surface model.
A good 'explainer' for what river routing means is this one from van den Hurk, summarised in the two diagrams below. The overbank inundation bit is nothing more or less than including the dynamics of floodplains, i.e. the spread of the river channel when it is in flood (see image from here further below). The implementation of overbank inundation I'm working on is based on Simon Dadson's overbank inundation code from 2005-08 (see Dadson et al. 2010 or this earlier poster by Ian Ashpole).
For a summary of the work, see Simon Dadson's presentation here, Lewis et al. (2018) and the minutes of our meeting 25th January 2017 in Oxford here. This went into the JULES code at vn5.1 in early 2018, so now we are on to improving the code in various ways to bring it in line with current hydrological theory: see here and here and exploring implementation of other options, e.g. using CaMa-Flood directly (in collaboration with Dai Yamazaki at JAMSTEC).
Here is my presentation about this at the JULES meeting September 2020 link.
As part of my work for the NERC project Hydro-JULES and the UK Met Office project UKEP, I am currently working on modifying the JULES River Flow Model (RFM) to include an improved representation of the process of overbank inundation. Without this, modelled water courses in RFM cannot overflow their banks and inundate the surrounding landscape to form fluvial wetlands. Overbank inundation is generally implemented in fine-scale flood prediction models (e.g. CaMa-Flood, LISFLOOD), but is rarely implemented in a robust way in global-scale land surface models. In Hydro-JULES, we are working on a new framework for interactive overbank inundation in JULES. This will not only simulate inundation extent more reliably, but will also characterise feedbacks on ecosystem function in inundated areas, which is currently not represented in any land surface model.
A good 'explainer' for what river routing means is this one from van den Hurk, summarised in the two diagrams below. The overbank inundation bit is nothing more or less than including the dynamics of floodplains, i.e. the spread of the river channel when it is in flood (see image from here further below). The implementation of overbank inundation I'm working on is based on Simon Dadson's overbank inundation code from 2005-08 (see Dadson et al. 2010 or this earlier poster by Ian Ashpole).
For a summary of the work, see Simon Dadson's presentation here, Lewis et al. (2018) and the minutes of our meeting 25th January 2017 in Oxford here. This went into the JULES code at vn5.1 in early 2018, so now we are on to improving the code in various ways to bring it in line with current hydrological theory: see here and here and exploring implementation of other options, e.g. using CaMa-Flood directly (in collaboration with Dai Yamazaki at JAMSTEC).
Here is my presentation about this at the JULES meeting September 2020 link.
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