Hydraulic and flood-loss modeling of levee, floodplain, and river management strategies, Middle Mississippi River, USA

Abstract

In this investigation, four scenarios were used to quantify the balance between the benefits of levees for flood protection and their potential to increase flood risk using Hazards U.S. Multi-Hazard flood-loss software and hydraulic modeling of the Middle Mississippi River (MMR). The goals of this study were (1) to quantify the flood exposure under different flood-control configurations and (2) to assess the relative contributions of various engineered structures and flood-loss strategies to potential flood losses. Removing all the flood-control structures along the MMR, without buyouts or other mitigation, reduced the average flood stages between 2.3 m (100-year flood) and 2.5 m (500-year), but increased the potential flood losses by $4.3-6.7 billion. Removing the agricultural levees downstream of St. Louis decreased the flood stages through the metro region by *1.0 m for the 100-and 500-year events; flood losses, without buyouts or other mitigation, were increased by $155 million for the 100-year flood, but were decreased by $109 million for the 500-year flood. Thus, agricultural levees along the MMR protect against small-to medium-size floods (up to the *100-year flood level) but cause more damage than they prevent during large floods such as the 500-year flood. Buyout costs for the all the buildings within the 500-year floodplain downstream of urban flood-control structures near St. Louis are *40% less than the cost of repairing the buildings damaged by the 500-year flood. This suggests large-scale buyouts could be the most cost-effective option for flood loss mitigation for properties currently protected by agricultural levees.

Evolving flood patterns in a Mediterranean region (1301–2012) and climatic factors – the case of Catalonia

“…Apart from the low significance and agreement in precipitation trends, the complexity associated with flooding requires further analysis of the relationship between changes to floods and rainfall and the evolution of climatic and hydrologic parameters (Di Baldassarre et al, 2009;Heine and Pinter, 2012;Remo et al, 2012;Hall et al, 2014). Most of these authors stress the importance of changes to land use (Naef et al, 2002), or possible changes in runoff coefficients (Sivapalan et al, 2005;Mouri et al, 2011).…”

Socio-hydrology: conceptualising human-flood interactions

“…inundation of floodplains) shapes patterns of human settlements and land use (Myers et al, 2008;Green et al, 2011;Schultz and Elliott, 2012). Recent studies have also examined the impact of human interventions (such as flood control measures, land-use change, and urbanisation) on the frequency and magnitude of flooding (Di Baldassarre et al, 2009;Heine and Pinter, 2012;Remo et al, 2012).…”

Uncertainty in levee heights and its effect on the spatial pattern of flood hazard in a floodplain

“…Haddad et al (2015) used the genetic algorithm to optimize the location and height of levees with the aim of reducing the overall flood damage. Remo et al (2012) created different scenarios by using the current configuration of levees, complete removal of the levee system, and removing only the agricultural levees in the Mississippi River and assessed the possible damages for 100-and 500-year floods.…”