Data Preparation for Validation Study of Hazus Canada Flood Model

As our climate changes, the occurrence of extreme weather events and heavier rainfall becomes more common. This change in weather patterns and precipitation results in a greater number of recorded flood events and a larger magnitude of flood events. Canadian municipalities are therefore facing a pressing demand to perform hazard assessments to identify communities at risk and measure potential economic and societal losses due to flood events. Federal Emergency Management Agency (FEMA) developed a standardized tool, Hazus-MH, for loss estimation from natural disasters for use in the US. Recently, Hazus has been adapted for use in Canada. This paper introduces the Hazus flood loss assessment model and the adaption and development required for the Canadian Hazus release. Furthermore, the steps followed with respect to data acquisition and preparation of the required exposure and hazard input data and attribute translation methodology to conform to Hazus classifications for the pilot study in Fredericton, NB, are presented. A subsequent paper will report the flood model results and compare them to actual expenditures from the 2008 flood in Fredericton to verify the validity of the model, depth damage curves, and parameters employed

Developing conceptual hydrogeological model for Potsdam sandstones in southwestern Quebec, Canada

A hydrogeological study was conducted in Potsdam sandstones on the international border between Canada (Quebec) and the USA (New York). Two sandstone formations, arkose and conglomerate (base) and well-cemented quartz arenite (upper), underlie the study area and form the major regional aquifer unit. Glacial till, littoral sand and gravel, and marine silt and clay discontinuously overlie the aquifer. In both sandstone formations, sub-horizontal bedding planes are ubiquitous and display significant hydraulic conductivities that are orders of magnitude more permeable than the intact rock matrix. Aquifer tests demonstrate that the two formations have similar bulk hydrologic properties, with average hydraulic conductivities ranging from 2×10−5 to 4×10−5 m/s. However, due to their different lithologic and structural characteristics, these two sandstones impose rather different controls on groundwater flow patterns in the study area. Flow is sustained through two types of fracture networks: sub-horizontal, laterally extensive fractures in the basal sandstone, where hydraulic connectivity is very good horizontally but very poor vertically and each of the water-bearing bedding planes can be considered as a separate planar two-dimensional aquifer unit; and the more fractured and vertically jointed system found in the upper sandstone that promotes a more dispersed, three-dimensional movement of groundwater. Une étude hydrogéologique a été entreprise dans les grès de Potsdam, sur la frontière entre le Canada (Québec) et les Etats-Unis (New York). Sous le secteur d’étude, deux formations gréseuses, les arkoses et conglomérats (base) et les arénites quartzeuses cimentées (sommet), forment une unité aquifère majeure à l’échelle régionale. Les moraines glaciaires, les sables et graviers littoraux, et les argiles et silts marins recouvrent l’aquifère de manière discontinue. Dans les deux formations gréseuses, les litages sub-horizontaux sont omniprésents, et présentent des conductivités hydrauliques significatives, supérieures de plusieurs ordres de grandeur à celles de la matrice rocheuse intacte. Les pompages d’essai démontrent que les deux formations ont des propriétés hydrologiques apparentes comparables, avec notamment des conductivités hydrauliques comprises entre 2×10−5 et 4× 10−5 m/s. Cependant, du fait de leurs lithologies et de leurs caractéristiques structurales contrastées, ces deux formations gréseuses imposent des contrôles différents sur les écoulements souterrains dans le secteur d’étude. L’écoulement est soutenu par deux types de réseaux de fractures : des fractures latéralement extensives subhorizontales dans les grès de base, où la connectivité hydraulique est très bonne horizontalement mais médiocre verticalement, et où chacun des plans aquifères peut être considéré comme une unité aquifère isolée plane bidimensionnelle, et un système fissuré verticalement et plus fracturé situé dans les grès supérieurs, qui favorise des écoulements souterrains tridimensionnels et plus dispers

Developing conceptual hydrogeological model for Potsdam sandstones in southwestern Quebec, Canada

A hydrogeological study was conducted in Potsdam sandstones on the international border between Canada (Quebec) and the USA (New York). Two sandstone formations, arkose and conglomerate (base) and well-cemented quartz arenite (upper), underlie the study area and form the major regional aquifer unit. Glacial till, littoral sand and gravel, and marine silt and clay discontinuously overlie the aquifer. In both sandstone formations, sub-horizontal bedding planes are ubiquitous and display significant hydraulic conductivities that are orders of magnitude more permeable than the intact rock matrix. Aquifer tests demonstrate that the two formations have similar bulk hydrologic properties, with average hydraulic conductivities ranging from 2×10−5 to 4×10−5 m/s. However, due to their different lithologic and structural characteristics, these two sandstones impose rather different controls on groundwater flow patterns in the study area. Flow is sustained through two types of fracture networks: sub-horizontal, laterally extensive fractures in the basal sandstone, where hydraulic connectivity is very good horizontally but very poor vertically and each of the water-bearing bedding planes can be considered as a separate planar two-dimensional aquifer unit; and the more fractured and vertically jointed system found in the upper sandstone that promotes a more dispersed, three-dimensional movement of groundwater. Une étude hydrogéologique a été entreprise dans les grès de Potsdam, sur la frontière entre le Canada (Québec) et les Etats-Unis (New York). Sous le secteur d’étude, deux formations gréseuses, les arkoses et conglomérats (base) et les arénites quartzeuses cimentées (sommet), forment une unité aquifère majeure à l’échelle régionale. Les moraines glaciaires, les sables et graviers littoraux, et les argiles et silts marins recouvrent l’aquifère de manière discontinue. Dans les deux formations gréseuses, les litages sub-horizontaux sont omniprésents, et présentent des conductivités hydrauliques significatives, supérieures de plusieurs ordres de grandeur à celles de la matrice rocheuse intacte. Les pompages d’essai démontrent que les deux formations ont des propriétés hydrologiques apparentes comparables, avec notamment des conductivités hydrauliques comprises entre 2×10−5 et 4× 10−5 m/s. Cependant, du fait de leurs lithologies et de leurs caractéristiques structurales contrastées, ces deux formations gréseuses imposent des contrôles différents sur les écoulements souterrains dans le secteur d’étude. L’écoulement est soutenu par deux types de réseaux de fractures : des fractures latéralement extensives subhorizontales dans les grès de base, où la connectivité hydraulique est très bonne horizontalement mais médiocre verticalement, et où chacun des plans aquifères peut être considéré comme une unité aquifère isolée plane bidimensionnelle, et un système fissuré verticalement et plus fracturé situé dans les grès supérieurs, qui favorise des écoulements souterrains tridimensionnels et plus dispers

RAPID RISK EVALUATION (ER²) USING MS EXCEL SPREADSHEET: A CASE STUDY OF FREDERICTON (NEW BRUNSWICK, CANADA)

Conventional knowledge of the flood hazard alone (extent and frequency) is not sufficient for informed decision-making. The public safety community needs tools and guidance to adequately undertake flood hazard risk assessment in order to estimate respective damages and social and economic losses. While many complex computer models have been developed for flood risk assessment, they require highly trained personnel to prepare the necessary input (hazard, inventory of the built environment, and vulnerabilities) and analyze model outputs. As such, tools which utilize open-source software or are built within popular desktop software programs are appealing alternatives. The recently developed Rapid Risk Evaluation (ER2) application runs scenario based loss assessment analyses in a Microsoft Excel spreadsheet. User input is limited to a handful of intuitive drop-down menus utilized to describe the building type, age, occupancy and the expected water level. In anticipation of local depth damage curves and other needed vulnerability parameters, those from the U.S. FEMA’s Hazus-Flood software have been imported and temporarily accessed in conjunction with user input to display exposure and estimated economic losses related to the structure and the content of the building. Building types and occupancies representative of those most exposed to flooding in Fredericton (New Brunswick) were introduced and test flood scenarios were run. The algorithm was successfully validated against results from the Hazus-Flood model for the same building types and flood depths

Development of a Data Warehouse for Riverine and Coastal Flood Risk Management

In New Brunswick flooding occurs typically during the spring freshet, though, in recent years, midwinter thaws have led to flooding in January or February. Municipalities are therefore facing a pressing need to perform risk assessments in order to identify communities at risk of flooding. In addition to the identification of communities at risk, quantitative measures of potential structural damage and societal losses are necessary for these identified communities. Furthermore, tools which allow for analysis and processing of possible mitigation plans are needed. Natural Resources Canada is in the process of adapting Hazus-MH to respond to the need for risk management. This requires extensive data from a variety of municipal, provincial, and national agencies in order to provide valid estimates. The aim is to establish a data warehouse to store relevant flood prediction data which may be accessed thru Hazus. Additionally, this data warehouse will contain tools for On-Line Analytical Processing (OLAP) and knowledge discovery to quantitatively determine areas at risk and discover unexpected dependencies between datasets. The third application of the data warehouse is to provide data for online visualization capabilities: web-based thematic maps of Hazus results, historical flood visualizations, and mitigation tools; thus making flood hazard information and tools more accessible to emergency responders, planners, and residents. This paper represents the first step of the process: locating and collecting the appropriate datasets

Quantifying exposure of linear infrastructures to earthquake-triggered transverse landslides in permafrost thawing slopes

The seismic shaking can cause slope instability in otherwise relatively stable permafrost terrains. In addition, rapid ice melting in low-permeability fine-grained soils can lead to excess pore water pressure build up and cause instability in slopes even at small angles. This study addresses the active layer detachment (ALD) slope instability hazard and develops a systematic risk assessment framework for existing and future linear infrastructures such as energy pipelines, bridges and roads traversing permafrost regions. Mild slopes, with average gradient of 7째, are considered in this study as the most representative of actual field conditions. The potential for earthquake-triggered ALD is analytically quantified. State-of-the-art Canadian North ALD morphological statistics are combined with seismic slope stability analyses to determine: (i) the probability of linear infrastructure exposure to permanent ground deformations (PGD) caused by ALD, and (ii) the extent of the potential PGD that the linear infrastructure may be subjected to. Monte Carlo technique is applied to simulate and assess the sensitivity of the model to parameters such as earthquake magnitude and source-to-site distance. The findings from this study can be used to evaluate the vulnerability of linear infrastructures exposed to the ALD hazard.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author