scholarly journals The influence of the net rainfall mixed Curve Number – Green Ampt procedure in flood hazard mapping: a case study in Central Italy

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Andrea Petroselli ◽  
Ettore Arcangeletti ◽  
Elena Allegrini ◽  
Nunzio Romano ◽  
Salvatore Grimaldi
Keyword(s):  
Flood Hazard ◽  
Central Italy ◽  
Estimation Procedure ◽  
Curve Number ◽  
Flood Mapping ◽  
Hazard Mapping ◽  
Rainfall Estimation ◽  
Infiltration Model ◽  
Conductivity Parameter ◽  
Scs Cn

A net rainfall estimation procedure, referred to as Curve-Number For Green-Ampt (CN4GA), combining the Soil Conservation Service - Curve Number (SCS-CN) method and the Green and Ampt (GA) infiltration equation was recently developed, aiming to distribute at subdaily time resolution the information provided by the SCS-CN method. The initial abstraction and the total volume of rainfall provided by the SCS-CN method are used to identify the ponding time and to quantify the hydraulic conductivity parameter of the GA equation, whereas the GA infiltration model distributes the total volume of the rainfall excess provided by the SCS-CN method. In this study we evaluate the proposed procedure with reference to a real case comparing the flood mapping obtained applying the event-based approach for two different net rainfall scenarios: the proposed CN4GA and the common SCS-CN. Results underline that the net rainfall estimation step can affect the final flood mapping result.

scholarly journals Effects of rating-curve uncertainty on probabilistic flood mapping

2012 ◽  
Vol 9 (8) ◽  
pp. 9809-9845 ◽  
Author(s):  
A. Domeneghetti ◽  
S. Vorogushyn ◽  
A. Castellarin ◽  
B. Merz ◽  
A. Brath
Keyword(s):  
Boundary Conditions ◽  
Confidence Intervals ◽  
Flood Risk ◽  
Flood Hazard ◽  
Assessment Model ◽  
Flood Mapping ◽  
Hazard Mapping ◽  
Rating Curve ◽  
Sources Of Uncertainty ◽  
Definition Of

Abstract. Comprehensive flood risk assessment studies should quantify the global uncertainty in flood hazard estimation, for instance by mapping inundation extents together with their confidence intervals. This appears of particular importance in case of flood hazard assessments along dike-protected reaches where the possibility of occurrence of dike failures may considerably enhance the uncertainty. We present a methodology to derive probabilistic flood maps in dike-protected flood prone areas, where several sources of uncertainty are taken into account. In particular, this paper focuses on a 50 km reach of River Po (Italy) and three major sources of uncertainty in hydraulic modelling and flood mapping: uncertainties in the (i) upstream and (ii) downstream boundary conditions, and (iii) uncertainties in dike failures. Uncertainties in the definition of upstream boundary conditions (i.e. design-hydrographs) are assessed by applying different bivariate copula families to model the frequency regime of flood peaks and volumes. Uncertainties in the definition of downstream boundary conditions are characterised by associating the rating-curve used as downstream boundary condition with confidence intervals which reflect discharge measurements errors and interpolation errors. The effects of uncertainties in boundary conditions and randomness of dike failures are assessed by means of the Inundation Hazard Assessment Model (IHAM), a recently proposed hybrid probabilistic-deterministic model that considers three different failure mechanisms: overtopping, piping and micro-instability due to seepage. The results of the study show that the IHAM-based analysis enables probabilistic flood hazard mapping and provides decision makers with a fundamental piece of information for devising and implementing flood risk mitigation strategies in the presence of various sources of uncertainty.

scholarly journals A GIS-Based Hydrological Modeling Approach for Rapid Urban Flood Hazard Assessment

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1483
Author(s):  
Qianqian Zhou ◽  
Jiongheng Su ◽  
Karsten Arnbjerg-Nielsen ◽  
Yi Ren ◽  
Jinhua Luo ◽  
...  
Keyword(s):  
Large Scale ◽  
Hydrological Modeling ◽  
Performance Indicator ◽  
Flood Hazard ◽  
Flood Mapping ◽  
Hazard Mapping ◽  
Flood Hazards ◽  
Topographic Wetness Index ◽  
Urban Flood ◽  
Mapping Techniques

Urban floods are detrimental to societies, and flood mapping techniques provide essential support for decision-making on the better management of flood risks. This study presents a GIS-based flood characterization methodology for the rapid and efficient identification of urban flood-prone areas, which is especially relevant for large-scale flood hazards and emergency assessments for data-scarce studies. The results suggested that optimal flood mapping was achieved by adopting the median values of the thresholds for local depression extraction, the topographic wetness index (TWI) and aggregation analyses. This study showed the constraints of the depression extraction and TWI methods and proposed a methodology to improve the performance. A new performance indicator was further introduced to improve the evaluation ability of hazard mapping. It was shown that the developed methodology has a much lower demand on the data and computation efforts in comparison to the traditional two-dimensional models and, meanwhile, provides relatively accurate and robust assessments of flood hazards.

scholarly journals Integrating GIS-Based MCDA Techniques and the SCS-CN Method for Identifying Potential Zones for Rainwater Harvesting in a Semi-Arid Area

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 704
Author(s):  
Hussein Al-Ghobari ◽  
Ahmed Z. Dewidar
Keyword(s):  
Water Conservation ◽  
Surface Runoff ◽  
Rainwater Harvesting ◽  
Global Climate ◽  
Remote Sensing Data ◽  
Curve Number ◽  
Drainage Density ◽  
Promising Alternative ◽  
Thematic Layers ◽  
Scs Cn

An increasing scarcity of water, as well as rapid global climate change, requires more effective water conservation alternatives. One promising alternative is rainwater harvesting (RWH). Nevertheless, the evaluation of RWH potential together with the selection of appropriate sites for RWH structures is significantly difficult for the water managers. This study deals with this difficulty by identifying RWH potential areas and sites for RWH structures utilizing geospatial and multi-criteria decision analysis (MCDA) techniques. The conventional data and remote sensing data were employed to set up needed thematic layers using ArcGIS software. The soil conservation service curve number (SCS-CN) method was used to determine surface runoff, centered on which yearly runoff potential map was produced in the ArcGIS environment. Thematic layers such as drainage density, slope, land use/cover, and runoff were allotted appropriate weights to produced RWH potential areas and zones appropriate for RWH structures maps of the study location. Results analysis revealed that the outcomes of the spatial allocation of yearly surface runoff depth ranging from 83 to 295 mm. Moreover, RWH potential areas results showed that the study areas can be categorized into three RWH potential areas: (a) low suitability, (b) medium suitability, and (c) high suitability. Nearly 40% of the watershed zone falls within medium and high suitability RWH potential areas. It is deduced that the integrated MCDA and geospatial techniques provide a valuable and formidable resource for the strategizing of RWH within the study zones.

scholarly journals Flood hazard mapping and assessment in data-scarce Nyaungdon area, Myanmar

PLoS ONE ◽  
2019 ◽  
Vol 14 (11) ◽  
pp. e0224558 ◽  
Author(s):  
Zaw Myo Khaing ◽  
Ke Zhang ◽  
Hisaya Sawano ◽  
Badri Bhakra Shrestha ◽  
Takahiro Sayama ◽  
...  
Keyword(s):  
Flood Hazard ◽  
Hazard Mapping
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