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

Sanyal, Joy

doi:10.1080/02626667.2017.1334887

Cited by 17 publications

(11 citation statements)

References 28 publications

(28 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Altarejos-García et al (2012), Chatterjee et al (2008), Bates (2001, 2002), Kvočka et al (2015), and Neal et al (2012b) discuss the effects of the chosen inundation model, its parametrization, and the role of input data on flood modelling results. Other uncertainties in flood modelling outputs are related to uncertainties in levee heights (Sanyal, 2017) or digital elevation models (Saksena and Merwade, 2015). Beside the uncertainties in flood modelling, observational uncertainties also need to be recognized with recent studies highlighting the importance of observational errors in rainfall and discharge data (McMillan et al, 2012;Coxon et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Effects of variability in probable maximum precipitation patterns on flood losses

Zischg

Felder

Weingartner

et al. 2018

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. The assessment of the impacts of extreme floods is important for dealing with residual risk, particularly for critical infrastructure management and for insurance purposes. Thus, modelling of the probable maximum flood (PMF) from probable maximum precipitation (PMP) by coupling hydrological and hydraulic models has gained interest in recent years. Herein, we examine whether variability in precipitation patterns exceeds or is below selected uncertainty factors in flood loss estimation and if the flood losses within a river basin are related to the probable maximum discharge at the basin outlet. We developed a model experiment with an ensemble of probable maximum precipitation scenarios created by Monte Carlo simulations. For each rainfall pattern, we computed the flood losses with a model chain and benchmarked the effects of variability in rainfall distribution with other model uncertainties. The results show that flood losses vary considerably within the river basin and depend on the timing and superimposition of the flood peaks from the basin's sub-catchments. In addition to the flood hazard component, the other components of flood risk, exposure, and vulnerability contribute remarkably to the overall variability. This leads to the conclusion that the estimation of the probable maximum expectable flood losses in a river basin should not be based exclusively on the PMF. Consequently, the basin-specific sensitivities to different precipitation patterns and the spatial organization of the settlements within the river basin need to be considered in the analyses of probable maximum flood losses.

show abstract

Section: Introductionmentioning

confidence: 99%

Effects of variability in probable maximum precipitation patterns on flood losses

Zischg

Felder

Weingartner

et al. 2018

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

show abstract

“…The influence of the uncertainty associated with such elements on flood inundation predictions has been extensively analyzed in literature (see Merwade et al, 2008). In particular, Sanyal (2017) recently developed a probabilistic methodology for dealing with the effect of uncertainty in levee heights on the inundation pattern. 4.…”

Section: Limitations Of the Methodsmentioning

confidence: 99%

Probabilistic Assessment of Flood Hazard due to Levee Breaches Using Fragility Functions

D’Oria

Maranzoni

Mazzoleni

2019

Water Resources Research

View full text Add to dashboard Cite

Flood hazard maps are useful tools for land planning and flood risk management in order to increase the safety of flood‐prone areas that can be inundated in the event of levee failure. However, flood hazard assessment is affected by various uncertainties, both aleatory and epistemic. The flood hazard analysis should hence take into account the main sources of uncertainty and quantify the confidence of the results for a given design flood event. To this end, this paper presents a probabilistic method for flood hazard mapping, which considers uncertainty due to breach location and failure time. A reliability analysis of the discretized levee system, performed using the concept of fragility function, enables the preselection of a set of levee sections more susceptible to failure. The probabilities of the breach scenarios (characterized by different breach locations and times) are then calculated using the probability multiplication rule, neglecting multiple breaches. The method is applied to a 96‐km levee‐protected reach in the central portion of the Po River (Northern Italy) and to an adjacent 1,900‐km2 flood‐prone area on the right‐hand side of the river, with a focus on the piping breach mechanism. The numerical simulations are performed through a combined 1D‐2D hydrodynamic model using widespread free software. The results show that the method is effective for probabilistic inundation and flood hazard mapping. In addition, it has the advantage of requiring a smaller computational effort in comparison with the methods based on a classic Monte Carlo procedure.

show abstract

“…Unfortunately there does not appear to be a register of FPSs for India from which more realistic inputs to AGFA can be made. Also, the design floods take no account of the likelihood that embankments will increase the height of a flood because of reduction in the width of the floodplain, and the effect of spurs that protrude into the river from embankments that slow the flow and increase its height (Sanyal, 2017). Some of the supporting literature for AGFA mentions both the failure of embankments and also the levee (embankment) effect, but these phenomena are not included in AGFA.…”

Section: Flood Mitigation and Its Limitationsmentioning

confidence: 99%

Riverine Flood Hazard: Disaster Risk Reduction in India

Wasson¹,

Jain

Katuri³

et al. 2018

Proceedings of the Indian National Science Academy

View full text Add to dashboard Cite

The economic risk from and social vulnerability to riverine floods in India is one of the highest, if not the highest, in the world, with millions of people exposed and vulnerable, and billions of rupees worth of property and infrastructure at risk. Between 1953 and 2011, the total number of human lives lost to floods was 97,551 and the total economic cost of floods in India was 4.506x10 12 INR (6912x10 7 USD) in 2017 prices. Embankments have been the dominant flood protection scheme, or Disaster Risk Reduction strategy, since Independence and despite the heroic construction of tens of thousands of embankments to protect lives and property from floods, economic damage continues to rise, even when normalized for inflation to take account of increasing wealth and therefore an increase in the amount of property that can be damaged. Explanations of this apparent paradox vary, but appear to centre on breaches in embankments, incomplete embankments, sedimentation in channels because of embankments and therefore deeper and more dangerous floods, human encroachment onto floodplains partly as a result of 'the levee effect' whereby people feel safe in the presence of embankments, and the displacement of traditional coping mechanisms by government initiatives. While governments, NGOs, and academics have often discussed non-structural DRR, and some is in place, there has been little development of this approach to more completely complement structural interventions to reduce deaths and damage. A workshop of flood management practitioners and analysts in February 2017 produced a set of recommendations for a more robust form of DRR for India, and they are presented as a contribution to at least moderate what has become an existential crisis for many Indians.

show abstract

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

Cited by 17 publications

References 28 publications

Effects of variability in probable maximum precipitation patterns on flood losses

Effects of variability in probable maximum precipitation patterns on flood losses

Probabilistic Assessment of Flood Hazard due to Levee Breaches Using Fragility Functions

Riverine Flood Hazard: Disaster Risk Reduction in India

Contact Info

Product

Resources

About