## 1 Introduction  
Some research studies support the notion that the severity and frequency of floods have increased in recent years [1]. Flood situations are likely to worsen due to climate change, land subsidence, urbanization, and population growth. Floods will become more frequent, prevalent, and serious in the future due to demography, lifestyle, and climate trends [2]. Greater flood damage demands an effective decision-making system for flood management and makes a revision of existing strategies a priority. [PERSON], [PERSON] et al. [3] emphasized a detailed economic analysis of flood events before the decision-makers deploy flood mitigation options.  
As to flooding, it is not a new issue, and neither are the solutions being proposed. However, with the ever-increasing awareness of environmental concerns, living standards, and evolved technical expertise, the expectations of having a more efficient flood management approach is natural and justifiable. As a result, several flood management options, theories, approaches, measures, plans, and strategies are emerging. Some examples are flood protection, evacuation, environmentally friendly solutions, renaturalization of rivers, foolproof structural measures, nonstructural measures, soft measures, hard measures, room for the river, flood fighting, the resilient approach, sustainable flood management, the integrated approach, risk-based flood management, living with floods, nature-based solutions, economical solutions, spatial planning modifications, flood risk zoning, coping with floods, floodplain restoration, the no-adverse-impact approach, catchment management, community cooperation, compensation, dikes, floodwalls, warning systems, encroachment control, flood insurance, floodproofing, flow diversion, groundwater recharge, public awareness, relief efforts, river improvement, storage and retention, and sustainable drainage systems.  
Flood management practices have evolved on the basis of the severity of floods and the socioeconomic aspects of a region. A single solution cannot be extended to all flood situations because the situations are not the same everywhere [4]. Climate variability, land use, and land cover are among the significant parameters affecting the regime of flooding [5]. Solutions have to be determined by the socioeconomic aspects of a country and flood behavior [6]. However, probability-based flood design prevails worldwide. For example, the 1/100-year flood is the de facto flood risk management norm in the US [7; 8; 9]. The 1/100-year flood is considered the base-flood for all structural and nonstructural designs. The UK's typical design tolerance for urban areas is 1% and 0.5% probability of floods [10; 11]. The Netherlands protects its population by 53 dike rings with a design probability of 1/1250 for river floods and up to 1/10,000 probability for the coasts of South Holland [12; 13]. Flood safety standards along the coast are based on a 100-year flood return period in Germany and Austria [14]. Flood protection safety standards along the main courses of rivers differ greatly and range from 1/30 years to 1/1000 years along the upper Rhine [15]. In France, only one return period is calculated for flood hazards [16]. A 100-year flood is a widely accepted design standard for flood protection measures in many parts of the world [17].  
Risk-based assessment methods were introduced during the 1990s in the field of flood management, and they provide a clear focus on flood impacts and the reduction of all possible flood-related risks [18]. However, three decades on, the probability-based flood protection design has become predominant due to the absence of rigid and well-modeled risk-based flood management design criteria. Other than the differences in development approaches and design criteria, the associated regulations and guidelines are not uniform for risk-based flood management throughout the world.