Rapid assessment of flood susceptibility in urbanized rivers using digital terrain data: Application to the Arno river case study (Firenze, northern Italy)

Abstract As a result of the recent acquisitions of detailed geographic data in fluvial environments this study proposes an analytical procedure in a GIS environment for an easy, rapid and cost-effective evaluation of flood susceptibility within urban and sub-urban areas. The method, based on data gathering in various public offices and possibly integrating missing geomorphologic information with new records, has been tested in a real case study in central Italy from which operational instructions could be extrapolated for other similar areas in the world. A long reach of the Arno river, which is currently the most important national hydraulic emergency area in terms of civil protection, was selected for this purpose. The measured dike heights, extrapolated from a geographic database previously created by the authors on behalf of the Provincia di Firenze administration, were compared with the results of hydraulic modeling conducted by the Arno River Basin Authority in which water flood levels were simulated for various return periods. This data comparison has allowed us to identify critical points for overflow hazard. In addition, the flood discharges provided by the same model were related to the freeboard typically used in river hydraulics for the major Italian watercourses (1.00 m for a 200-year flood). A deeper analysis of the flood susceptibility was subsequently carried over to the urban area of Firenze. A model of the surface hydrological flows concentrated on the historic center has provided a comprehensive response of this area to the sudden appearance of abundant surface-water flows. The behavior of the urban water circulation in terms of path and areas involved were promptly identified with great precision during normal flow conditions of the Arno in the event of river obstruction at bridges and in case of undifferentiated runoff out from the riverbed.

[1]  A. Overeem,et al.  Soil buffer limits flash flood response to extraordinary rainfall in a Dutch lowland catchment , 2011 .

[2]  C. Maksimovic,et al.  Urban pluvial flooding: Development of GIS based pathway model for surface flooding and interface with surcharged sewer model , 2007 .

[3]  D. Tarboton,et al.  Advances in the mapping of flow networks from digital elevation data , 2001 .

[4]  J. Li,et al.  Smart city and the applications , 2011, 2011 International Conference on Electronics, Communications and Control (ICECC).

[5]  Guohe Huang,et al.  A study on DEM-derived primary topographic attributes for hydrologic applications: Sensitivity to elevation data resolution , 2008 .

[6]  Wittaya Daungthima,et al.  Assessing the Flood Impacts and the Cultural Properties Vulnerabilities in Ayutthaya, Thailand☆ , 2013 .

[7]  Fausto Guzzetti,et al.  Evaluation of Flood and Landslide Risk to the Population of Italy , 2005, Environmental management.

[8]  D. Tarboton.  A new method for the determination of flow directions and upslope areas in grid digital elevation models , 1997 .

[9]  Andre Zerger,et al.  Beyond Modelling: Linking Models with GIS for Flood Risk Management , 2004 .

[10]  Urban flood hazard and its mitigation , 1995 .

[11]  G. Pranzini,et al.  Evoluzione dell'idrografia nella Toscana centro-settentrionale , 1988 .

[12]  Billy J. Barfield,et al.  Design Hydrology and Sedimentology for Small Catchments , 1994 .

[13]  A. Simon,et al.  Bed-level adjustments in the Arno River, central Italy , 1998 .

[14]  Simona G. Lanza,et al.  Flood hazard threat on cultural heritage in the town of Genoa (Italy) , 2003 .

[15]  Samuele Segoni,et al.  Urban planning, flood risk and public policy: The case of the Arno River, Firenze, Italy , 2012 .

[16]  P. Tacconi,et al.  The Fluvial Dynamics of the Arno River , 2005 .

[17]  V. Kale.  Geomorphic effects of monsoon floods on Indian rivers , 2003 .

[18]  M. Rinaldi.  Recent channel adjustments in alluvial rivers of Tuscany, central Italy , 2003 .

[19]  T. Coulthard,et al.  The Hull floods of 2007: implications for the governance and management of urban drainage systems , 2010 .

[20]  Tim Webster,et al.  Using topographic lidar to map flood risk from storm-surge events for Charlottetown, Prince Edward Island, Canada , 2004 .

[21]  A. Müller,et al.  Flood and heat hazards in the Metropolitan Region of Santiago de Chile and the socio-economics of exposure , 2013 .

[22]  N. Surian,et al.  Morphological response to river engineering and management in alluvial channels in Italy , 2003 .

[23]  Massimo Rinaldi,et al.  Human impact on sediment yield and channel dynamics in the Arno River basin (central Italy) , 1996 .

[24]  Narendra Singh Raghuwanshi,et al.  Hydrodynamic modelling of a large flood‐prone river system in India with limited data , 2009 .

[25]  T. I. Eldho,et al.  A web GIS based integrated flood assessment modeling tool for coastal urban watersheds , 2014, Comput. Geosci..

[26]  Milan Holický,et al.  Assessment of Flooding Risk to Cultural Heritage in Historic Sites , 2010 .

[27]  M. Coli,et al.  Note di geologia fiorentina , 2007 .

[28]  Jim W. Hall,et al.  Fluvial flood risk management in a changing world , 2010 .

[29]  A. Paquier,et al.  Modeling floods in a dense urban area using 2D shallow water equations , 2006 .

[30]  Theo G. Schmitt,et al.  Analysis and modeling of flooding in urban drainage systems , 2004 .

[31]  E. Penning‐Rowsell,et al.  Estimating Injury and Loss of Life in Floods: A Deterministic Framework , 2005 .

[32]  F. Nencini.  FIRENZE, I GIORNI DEL DILUVIO , 1967 .

[33]  Miloš Drdácký.  Impact of Floods on Heritage Structures , 2010 .

[34]  Hannes Taubenböck,et al.  Flood risks in urbanized areas – multi-sensoral approaches using remotely sensed data for risk assessment , 2011 .

[35]  Aloysius Wehr,et al.  Airborne laser scanning—an introduction and overview , 1999 .

[36]  G. Corti,et al.  Active Tectonics and Seismic Zonation of the Urban Area of Florence, Italy , 2001 .

[37]  David G. Tarboton,et al.  On the extraction of channel networks from digital elevation data , 1991 .

[38]  Nicola Casagli,et al.  Mechanisms of riverbank failure along the Arno River, central Italy , 2003 .

[39]  B. Russo,et al.  Real-time urban flood forecasting and modelling – a state of the art , 2013 .

[40]  C. Doswell,et al.  Flash Flood Forecasting: An Ingredients-Based Methodology , 1996 .

[41]  Phong Tran,et al.  GIS and local knowledge in disaster management: a case study of flood risk mapping in Viet Nam. , 2009, Disasters.

[42]  F. Capecchi,et al.  Il bacino lacustre di Firenze-Prato-Pistoia; geologia del sottosuolo e ricostruzione evolutiva , 1975 .

[43]  M Brown,et al.  Usability of Geographic Information: current challenges and future directions. , 2013, Applied ergonomics.

[44]  S. Djordjević,et al.  Urban flood impact assessment: A state-of-the-art review , 2015 .

[45]  J. Marco,et al.  Urban flooding: the flood-planned city concept , 1994 .

[46]  A. N. Strahler.  Hypsometric (area-altitude) analysis of erosional topography. , 1952 .

[47]  Clément,et al.  An application of Geographic Information System in mapping flood risk zones in a north central city in Nigeria , 2013 .

[48]  A. Casas,et al.  The topographic data source of digital terrain models as a key element in the accuracy of hydraulic flood modelling , 2006 .

[49]  W. Winston,et al.  Geochemical variations during flash flooding, Meramec River basin, May 2000 , 2002 .

[50]  Fausto Guzzetti,et al.  Societal landslide and flood risk in Italy. , 2010 .

[51]  C. Hardie.  The Origin and Plan of Roman Florence , 1965, Journal of Roman Studies.

[52]  José I. Barredo,et al.  Major flood disasters in Europe: 1950–2005 , 2007 .

[53]  George Alan Blackburn,et al.  A real-time hydrological model for flood prediction using GIS and the WWW , 2003, Comput. Environ. Urban Syst..

[54]  S. K. Jenson,et al.  Extracting topographic structure from digital elevation data for geographic information-system analysis , 1988 .

[55]  N. Casagli,et al.  The Arno River Floods , 2005 .

[56]  E. Dinelli,et al.  Geochemistry of trace elements in surface waters of the Arno River Basin, northern Tuscany, Italy , 2009 .

[57]  Dimitrios Kolymbas,et al.  Geotechnical Problems of Cultural Heritage due to Floods , 2010 .

[58]  A. Soldati,et al.  Artificial neural network approach to flood forecasting in the River Arno , 2003 .

[59]  Gabriela Cembrano,et al.  Optimal control of urban drainage systems. A case study , 2004 .