Abstract
An improved understanding of changes in flood hazard and the underlying driving mechanisms is critical for predicting future changes for better adaptation strategies. While recent increases in flooding across the world have been partly attributed to a range of atmospheric or landscape drivers, one often-forgotten driver of changes in flood properties is the variability of river conveyance capacity. This paper proposes a new framework for connecting flood changes to longitudinal variability in river conveyance, precipitation climatology, flows and sediment connectivity. We present a first step, based on a regional analysis, towards a longer-term research effort that is required to decipher the circular causality between floods and rivers. The results show how this system of interacting units in the atmospheric, hydrologic and geomorphological realm function as a nonlinear filter that fundamentally alters the frequency of flood events. To revise and refine our estimation of future flood risk, this work highlights that multidriver attribution studies are needed, that include boundary conditions such as underlying climate, water and sediment connectivity, and explicit estimations of river conveyance properties.
Highlights
An improved understanding of changes in flood hazard and the underlying driving mechanisms is critical for predicting future changes for better adaptation strategies
Flood studies typically separate slowly varying boundary conditions of the Earth System from the fast varying hydrological processes. We suggest this approach may no longer be appropriate for estimating future flood risk in a changing world - i.e. for critical infrastructure with a horizon typically within 10–30 yrs
Hydraulic Scaling Function(s) (HSF), as power-law functions representing the longitudinal variability of river bankfull geometry
Summary
The investigated landscape framework includes the variables and acronyms summarised in Table 1, and it considers:. Hydraulic Scaling Function(s) (HSF), as power-law functions representing the longitudinal variability of river bankfull geometry. HSFs provide information on the overall river morphology and storage capacity[40]. They offer a quantitative description of how channel width and related properties (depth, velocity) vary with changing discharge along the river course (‘downstream’ hydraulic geometry) and between rivers at a comparable discharge frequency. We focus on the coefficients of the power-law that relates bankfull-channel dimensions (width wbkf) to drainage area (ALidar) (Chapt 7.1, and 1.2 in supplementary material). River flows and characteristic properties of the daily flow distribution[43,44], and the decadal trend of exceedance of specific flow quantiles[38] We will generally refer to ‘climate’ speaking about this specific element
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
