Keywords
Future flood risk, Flood-landuse change interaction, Dynamic exposure, Flood risk reduction
Start Date
15-9-2020 9:20 AM
End Date
15-9-2020 9:40 AM
Abstract
In 2018 the Red Cross published a report stating that for the past 10 years, out of 3,751 natural hazard events, 40.5% were flood related. Globally, these flood events caused approximately a combined damage of US$363bn. In 2010 roughly 34,000km² of the 100-year floodplains were occupied by urban land use with an estimated exposure of US$21 trillion. Further urban development within the floodplains is likely to increase this potential damage. For example, it is estimated that in 2050 the urban area in the 100-year floodplain will be 49,000km² with the exposure being tripled compared to 2010 at US$63 trillion. In addition to increasing exposure, these urban developments will also alter the flood hazard by increasing (i) runoff volume due to reduced infiltration and (ii) runoff times due to decreased resistance. It is therefore necessary to consider the two-way interaction between flood and land use change when assessing future flood risk and determining appropriate mitigation strategies. In order to enable this to be achieved, a modelling framework that considers to evolution of the two-way interaction between land-use change and flooding over time is proposed, thereby reducing the uncertainty associated with estimates of future flood risk. The framework links land use, flood and impact models, enabling the effectiveness of a range of risk-reduction strategies, such as structural measures and land-use planning, to be assessed. The impact of a range of future climate, population growth and economic development scenarios can also be considered, enabling adaptive mitigation strategies that perform well under a range of plausible future conditions to be developed. Further, a conducted case study uses the framework on the Gawler River catchment to test the impact of the two-way interaction with different mitigation options. The dynamic interaction between flood and land use modelling improves decision making regarding future flood risk management.
A coupled flood and land-use modelling approach to reduce uncertainty in flood risk management
In 2018 the Red Cross published a report stating that for the past 10 years, out of 3,751 natural hazard events, 40.5% were flood related. Globally, these flood events caused approximately a combined damage of US$363bn. In 2010 roughly 34,000km² of the 100-year floodplains were occupied by urban land use with an estimated exposure of US$21 trillion. Further urban development within the floodplains is likely to increase this potential damage. For example, it is estimated that in 2050 the urban area in the 100-year floodplain will be 49,000km² with the exposure being tripled compared to 2010 at US$63 trillion. In addition to increasing exposure, these urban developments will also alter the flood hazard by increasing (i) runoff volume due to reduced infiltration and (ii) runoff times due to decreased resistance. It is therefore necessary to consider the two-way interaction between flood and land use change when assessing future flood risk and determining appropriate mitigation strategies. In order to enable this to be achieved, a modelling framework that considers to evolution of the two-way interaction between land-use change and flooding over time is proposed, thereby reducing the uncertainty associated with estimates of future flood risk. The framework links land use, flood and impact models, enabling the effectiveness of a range of risk-reduction strategies, such as structural measures and land-use planning, to be assessed. The impact of a range of future climate, population growth and economic development scenarios can also be considered, enabling adaptive mitigation strategies that perform well under a range of plausible future conditions to be developed. Further, a conducted case study uses the framework on the Gawler River catchment to test the impact of the two-way interaction with different mitigation options. The dynamic interaction between flood and land use modelling improves decision making regarding future flood risk management.
Stream and Session
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