Environmental Science and Policy 75 (2017) 158–172 Contents lists available at ScienceDirect Environmental Science and Policy journal homepage: www.elsevier.com/locate/envsci Improving flood risk analysis for effectively supporting the implementation MARK of flood risk management plans: The case study of “Serio” Valley ⁎ Raffaele Albanoa, , Leonardo Mancusib, Andrea Abbateb a School of Engineering, University of Basilicata, Italy b Sustainable Development and Energy Resources Department, Research on Energy Systems SpA, Italy ARTICLE INFO ABSTRACT Keywords: The EU Flood Directive 2007/60 requires the assessment and delineation of flood risk maps. The latter should Flood Directive provide the required knowledge for the development of flood risk management plans (FRMPs), that should deal flood risk map with all features of risk management: e.g. preparation, protection and prevention, comprising also the phase of fl ood risk management the flood forecasting and warning systems, in addition to the emergency management. The risk maps, delineated cost-benefit analysis through the expert-drive qualitative (EDQ) approach currently adopted in several European countries, such as GIS Italy, fail to represent the information base that needed by stakeholders for selecting the suitable objectives and Italy fl fl FloodRisk designing the appropriate mitigation actions for ood risk management. In the EDQ approach, the ood hazard risk mitigation alternatives and the potential damage degree maps are combined by means of a matrix to obtain a qualitative flood risk map. risk reduction However, the performance of the risk matrix is not usually rigorous validated and, therefore, presents limits, such as subjective and not careful explained interpretation of rating and poor resolution, (due to range com- pression), that can produce errors in comparative ranking of risk areas. In this context, this paper proposes the FloodRisk approach that aims to improve the efficacy of flood risk map overcoming the limits of EDQ approach in supplying the knowledge base that allow to analyze costs and benefits of potential mitigation measures. However, the proposed approach is also able to involve the citizens in the flood management process, enhancing their awareness. An application of FloodRisk procedure is showed on a pilot case in “Serio” Valley, (North Italy), and its strengths and limits, in terms of additional efforts required in its application compared with EDQ pro- cedure, have been discussed focusing on the efficacy of the outcomes provided for the fulfillment of FRMPs. The results have demonstrated the ability of FloodRisk, respect to EDQ approach, to distinguish successfully different levels of vulnerability of exposure elements, thanks to the use of asset value and depth-damage curves, that allows a suitably evaluation of the effectiveness of risk mitigation strategies. In this light, a successfully appli- cation of a cost-benefit analysis of FloodRisk approach on a portfolio of alternative mitigation actions, (i.e. structural and non-structural measurements), has been demonstrated on the proposed study case. However, FloodRisk requires additional information, e.g. water depths assessment and assets values, and it needs a proper analysis and communication of the uncertainty in its results. Although they still exist limitations that impede, at present, the FloodRisk application without an adequate understanding and a critical consideration of the hazard, exposure and vulnerability characteristics of the study area, considerations are supplied on how the utilization of this approach can be maximized in the light of the next flood risk maps revision due by December 2019. 1. Introduction flood in the last 20 years. The expectation that the flood damages can increase over time with climate and land-use change and social growth Time and again, floods heavily impact land and society in all the in flood prone-areas (e.g. IPCC, 2013; Di Baldassarre et al., 2013; world (UNISDR, 2012; IPCC, 2012). Only in the period between 1990 Domeneghetti et al., 2015) has raised the public and policy makers’ and 2008, Salvati et al. (2010) reports 2321 flood events in Italy that, awareness for the need to manage risks in order to mitigate their causes according to the Global Emergency Events Database (EMDAT www. or consequences (e.g. de Moel et al., 2012; Alfieri et al., 2015). In this emdat.be), have caused about 1407 deaths and 2.8 million of injuries. light, The EU flood directive 2007/60 (European Parliament and the Moreover, the United Nation (UN, 2015) has estimated that one third of Council of the European Union, 2007) has highlighted the interest in world’s population (around 2.3 billion people) has been affected by the concept of flood risk management overcoming the falling and ⁎ Corresponding author. E-mail address: raff[email protected] (R. Albano). http://dx.doi.org/10.1016/j.envsci.2017.05.017 Received 30 December 2016; Received in revised form 29 May 2017; Accepted 30 May 2017 1462-9011/ © 2017 Elsevier Ltd. All rights reserved. R. Albano et al. Environmental Science and Policy 75 (2017) 158–172 misleading past management vision of complete safety that has not able extension of a research, begun with Mancusi et al., 2015; that aspires to to stop the continuous increasing of socio-economic flood impacts. This advance in the implementation of operative tools to improve the effi- mitigation of both flood hazard and its potential consequences should cacy of risk maps in supporting flood risk management. In Mancusi be achieved through structural and non-structural measures, e.g. land- et al., 2015; the authors have focused mainly on dam-break events, for use planning, flood zoning and private self-protection measures, taking which it is difficult to assesses an event probability and, therefore, the into account, in the utilized approach, the countries differences, even study was devoted only to damage assessment for a single event and, within the Europe. In particular, the EU Flood Directive 2007/60 re- hence, doesn’t covering all the aspect of flood risk assessment. quires the development of flood risk management plans (FRMPs) that An application of FloodRisk procedure is showed on a pilot case in should deal with all features of risk management: e.g. preparation, “Serio” Valley, (North Italy), and its strengths and limits, in terms of protection and prevention, comprising also the phase of the flood additional efforts required in its application compared with EDQ pro- forecasting and warning systems, in addition to the emergency man- cedure, have been highlighted focusing on the efficacy of the outcomes agement. Moreover, the flood risk maps should be able to provide the provided for the fulfillment of FRMPs (Section 3.4). Moreover, an ex- comprehension of information base on which stakeholders should select ample of how the proposed approach can be used to support decisions the suitable objectives and designing the appropriate mitigation actions through a cost-efficacy analysis of a portfolio of mitigation alternatives for the delineation of FRMPs. The complexity of these decisions is often (structural and non-structural) has been showed in Section 3.4.4 Fi- at the limit of or exceeds human cognitive capacities and so appropriate nally, discussion and final remarks is provided in Section 3.54 on how and advanced tools are needed to simplified decisions to a level which the proposed approach can be maximized for its adoption in the next we can handle (Albano et al., 2017b). Indeed, these end-users have revision of flood risk maps due by December 2019. need information to be easily and quickly interpretable properly con- textualized and, therefore, specifically tailored to their needs (Albano 2. Expert-driven qualitative (EdQ) damage and risk assessment in et al., 2015b; Michielsen et al., 2016). In this context, the Directive Italy: the EdQ approach in “Serio valley” offers general guidelines like the necessity of developing flood hazard and risk maps and management plans in each country, but it doesn’t The “Serio” River flows in the “Po” River Basin through the detail the methods or the approaches that can be applied in order to “Seriana” valley, taking origin from the Alps mountain range, in par- achieve these goals. In Italy, the Flood Directive has been transposed ticular the so called “Pre Alpi Orobiche” in the administrative area of into the national legislation by the legislative decree 49/2010 of 23 “Bergamo” Province (in “Lombardia” Region) (see Fig. 1). The river February 2010. Generally, two main quite different techniques are begins the plain reach near the city of Seriate, through the Bergamo and utilized for the delineation of flood risk maps: the expert-driven qua- Cremona Provinces, until the confluence in the “Adda” River. The litative approach (traditionally implemented by practitioners) and the valley floor is extensively urbanized and characterized by several in- quantitative approach based on flood damage models (as proposed by dustrial activities and many residential areas, among which the main the main scientific literature on the topic, see Merz et al., 2010 for a are Alzano Lombardo, Gazzaniga, Albino and Nembro. In this context, review), that permits to quantify potential damage and risk in monetary the fragmented building regulations during the 1950-60′s have led to terms. There is also a research branch that focuses on the delineation of vulnerability increasing in these areas. The IRPI (“Istituto per la Ricerca flood risk maps by the use of multicriteria approach, successfully ap- e la Protezione