Proper assessment of the economic risk from hazards is an important prerequisite toward enhancing... more Proper assessment of the economic risk from hazards is an important prerequisite toward enhancing resilience and is often overlooked or underestimated in importance. This research describes a metho...
Model output of localized flood grids are useful in characterizing flood hazards for properties l... more Model output of localized flood grids are useful in characterizing flood hazards for properties located in the Special Flood Hazard Area (SFHA—areas expected to experience a 1% or greater annual chance of flooding). However, due to the unavailability of higher return-period [i.e., recurrence interval, or the reciprocal of the annual exceedance probability (AEP)] flood grids, the flood risk of properties located outside the SFHA cannot be quantified. Here, we present a method to estimate flood hazards that are located both inside and outside the SFHA using existing AEP surfaces. Flood hazards are characterized by the Gumbel extreme value distribution to project extreme flood event elevations for which an entire area is assumed to be submerged. Spatial interpolation techniques impute flood elevation values and are used to estimate flood hazards for areas outside the SFHA. The proposed method has the potential to improve the assessment of flood risk for properties located both inside a...
Accurate economic loss assessment for natural hazards is vital for planning, mitigation, and actu... more Accurate economic loss assessment for natural hazards is vital for planning, mitigation, and actuarial purposes. The widespread and costly nature of flood, with the economically disadvantaged disproportionately victimized, makes flood loss assessment particularly important. A shortcoming in existing flood loss models is absence of partitioning the building economic value of average annual loss (AAL) into that borne by the homeowner and by flood insurance. This research models the flood AAL incurred by the homeowner vs. by the insurer, focusing on the National Flood Insurance Program in the U.S., using Monte Carlo simulation at the individual homeowner scale. A hypothetical case study reveals that a $1500 or $3000 deductible is associated with a homeowner portion of 13 or 24 percent of the AAL, respectively, with homeowner proportion relatively insensitive to the combinations of coverage, AAL, and increase in first-floor height evaluated. In general, results inform the proactive deci...
Wildfire is an important but understudied natural hazard in some areas. This research examined hi... more Wildfire is an important but understudied natural hazard in some areas. This research examined historical and future wildfire property risk at the census-block level in Louisiana, a U.S.A. state with relatively dense population and substantial vulnerability to loss from wildfire, despite its wet climate. Here wildfire risk is defined as the product of exposure and vulnerability to the hazard, where exposure is a function of the historical and anticipated future wildfire frequency/extent, and vulnerability is a function of population, structure and content property value, damage probability, and percent of properties damaged. The results revealed a historical (1992–2015) average annual statewide property loss due to wildfire of almost USD 5.6 million (in 2010 USD), with the greatest risk in southwestern inland, east-central, extreme northwestern, and coastal southwestern Louisiana. The geographic distribution of wildfire risk by 2050 will remain similar to that today, but the magnitu...
Background: Wildfire is an important but understudied natural hazard. As with other natural hazar... more Background: Wildfire is an important but understudied natural hazard. As with other natural hazards, wildfire research is all too often conducted at too broad a spatial scale to identify local or regional patterns. This study addresses these gaps by examining the current and future wildfire property risk at the census-block level in Louisiana, a U.S. state with relatively dense population and substantial vulnerability to loss from this hazard, despite its wet climate. Here wildfire risk is defined as the product of exposure and vulnerability to the hazard, where exposure is a function of the historical and anticipated future wildfire frequency and extent, and the latter is a function of population, structure and content property value, damage probability, and percent of property damaged. Results: Historical (1992−2015) average annual statewide property loss due to wildfire was $5,556,389 (2010$), with the greatest risk to wildfire in southwestern inland, east-central, extreme northw...
The land-water interface is of great importance due to its significance in resource extraction, c... more The land-water interface is of great importance due to its significance in resource extraction, coastal management and climate change vulnerability analysis. In the recent years, determination of shoreline requires more concern as the coast of Bangladesh is vulnerable to anticipated sea level rise due to climate change. Region specific shoreline determination is needed for resource extraction, coastal risk management and landuse planning. This report is produced to address the areas of erosion, accretion and stable shoreline along the coast of Kuakata for providing a basis to describe the extent of economic and environmental effects of present shore erosion and accretion. In this study, the shoreline change is primarily detected for three decades by comparing satellite imagery of 1989, 2003 and 2010, using Landsat TM 30m resolution images. Band Combination, Ratio Transformation, Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) algorithms are...
Louisiana, U.S.A., is among the world's most vulnerable places to coastal flooding. Increasin... more Louisiana, U.S.A., is among the world's most vulnerable places to coastal flooding. Increasing frequency/intensity of natural hazards under climate change scenarios is expected to exacerbate Louisiana's coastal flood risk. Although many factors are involved, land subsidence from marshland compaction and underground resource extraction, shoreline erosion accelerated by eustatic sea level rise (ESLR), and tropical-cyclone-induced storm surge are among the most important. While past research has focused on flood risk assessment and mitigation strategies, including climate change scenarios, few studies examine all of these factors collectively. This study shows present pluvial flood depth and the contributions of additional coastal subsidence and ESLR toward future (2050) pluvial flooding. Then, current tropical-storm-induced storm surge and future storm surge depth modeled by Louisiana's Coastal Protection and Restoration Authority (CPRA) under climate change scenarios are ...
Sinkholes (or dolines) are an often-overlooked environmental hazard. The processes that lead to t... more Sinkholes (or dolines) are an often-overlooked environmental hazard. The processes that lead to their formation are slow and insidious, which encourage a lack of awareness or concern for the potential danger, until the sudden, climactic formation leads to unexpected property damage and possibly human casualties. This research identifies the risk to residential properties to the sinkhole hazard, using Louisiana, United States as a case study. Risk is defined as the product of the hazard intensity and the loss to structure and contents within the building resulting from the hazard-related disaster. Results suggest that risk is highly scale-dependent. Although the risk due to sinkholes is small on a per capita basis statewide, especially when compared to the per capita risk of other natural hazards, the property risk for census tracts or census blocks partially or completely overlying a salt dome is substantial. At finer scales, Terrebonne Parish, in coastal southeastern Louisiana, has...
In recent years, shoreline determination has become an issue of increasing importance and concern... more In recent years, shoreline determination has become an issue of increasing importance and concern, especially at the local level, as sea level continues to rise. This study identifies the rates of absolute and net erosion, accretion, and shoreline stabilization along the coast of Kuakata, a vulnerable coastal region in south-central Bangladesh. Shoreline change was detected by applying remote sensing and geographic information system (RS-GIS)-based techniques by using Landsat Thematic Mapper (TM), Landsat 8 Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) satellite images at 30-m resolution from 1989, 2003, 2010, and 2020. The band combination (BC) method was used to extract the shoreline (i.e., land-water boundary) due to its improved accuracy over other methods for matching with the existing shoreline position. This study also used participatory rural appraisal (PRA) tools which revealed the societal impacts caused by the shoreline changes. Coupling RS-GIS and PRA ...
Leading flood loss estimation models include Federal Emergency Management Agency’s (FEMA’s) Hazus... more Leading flood loss estimation models include Federal Emergency Management Agency’s (FEMA’s) Hazus, FEMA’s Flood Assessment Structure Tool (FAST), and (U.S.) Hydrologic Engineering Center’s Flood Impact Analysis (HEC-FIA), with each requiring different data input. No research to date has compared the resulting outcomes from such models at a neighborhood scale. This research examines the building and content loss estimates by Hazus Level 2, FAST, and HEC-FIA, over a levee-protected census block in Metairie, in Jefferson Parish, Louisiana. Building attribute data in National Structure Inventory (NSI) 2.0 are compared against “best available data” (BAD) collected at the individual building scale from Google Street View, Jefferson Parish building inventory, and 2019 National Building Cost Manual, to assess the sensitivity of input building inventory selection. Results suggest that use of BAD likely enhances flood loss estimation accuracy over existing reliance on default data in the soft...
Proper assessment of the economic risk from hazards is an important prerequisite toward enhancing... more Proper assessment of the economic risk from hazards is an important prerequisite toward enhancing resilience and is often overlooked or underestimated in importance. This research describes a metho...
Model output of localized flood grids are useful in characterizing flood hazards for properties l... more Model output of localized flood grids are useful in characterizing flood hazards for properties located in the Special Flood Hazard Area (SFHA—areas expected to experience a 1% or greater annual chance of flooding). However, due to the unavailability of higher return-period [i.e., recurrence interval, or the reciprocal of the annual exceedance probability (AEP)] flood grids, the flood risk of properties located outside the SFHA cannot be quantified. Here, we present a method to estimate flood hazards that are located both inside and outside the SFHA using existing AEP surfaces. Flood hazards are characterized by the Gumbel extreme value distribution to project extreme flood event elevations for which an entire area is assumed to be submerged. Spatial interpolation techniques impute flood elevation values and are used to estimate flood hazards for areas outside the SFHA. The proposed method has the potential to improve the assessment of flood risk for properties located both inside a...
Accurate economic loss assessment for natural hazards is vital for planning, mitigation, and actu... more Accurate economic loss assessment for natural hazards is vital for planning, mitigation, and actuarial purposes. The widespread and costly nature of flood, with the economically disadvantaged disproportionately victimized, makes flood loss assessment particularly important. A shortcoming in existing flood loss models is absence of partitioning the building economic value of average annual loss (AAL) into that borne by the homeowner and by flood insurance. This research models the flood AAL incurred by the homeowner vs. by the insurer, focusing on the National Flood Insurance Program in the U.S., using Monte Carlo simulation at the individual homeowner scale. A hypothetical case study reveals that a $1500 or $3000 deductible is associated with a homeowner portion of 13 or 24 percent of the AAL, respectively, with homeowner proportion relatively insensitive to the combinations of coverage, AAL, and increase in first-floor height evaluated. In general, results inform the proactive deci...
Wildfire is an important but understudied natural hazard in some areas. This research examined hi... more Wildfire is an important but understudied natural hazard in some areas. This research examined historical and future wildfire property risk at the census-block level in Louisiana, a U.S.A. state with relatively dense population and substantial vulnerability to loss from wildfire, despite its wet climate. Here wildfire risk is defined as the product of exposure and vulnerability to the hazard, where exposure is a function of the historical and anticipated future wildfire frequency/extent, and vulnerability is a function of population, structure and content property value, damage probability, and percent of properties damaged. The results revealed a historical (1992–2015) average annual statewide property loss due to wildfire of almost USD 5.6 million (in 2010 USD), with the greatest risk in southwestern inland, east-central, extreme northwestern, and coastal southwestern Louisiana. The geographic distribution of wildfire risk by 2050 will remain similar to that today, but the magnitu...
Background: Wildfire is an important but understudied natural hazard. As with other natural hazar... more Background: Wildfire is an important but understudied natural hazard. As with other natural hazards, wildfire research is all too often conducted at too broad a spatial scale to identify local or regional patterns. This study addresses these gaps by examining the current and future wildfire property risk at the census-block level in Louisiana, a U.S. state with relatively dense population and substantial vulnerability to loss from this hazard, despite its wet climate. Here wildfire risk is defined as the product of exposure and vulnerability to the hazard, where exposure is a function of the historical and anticipated future wildfire frequency and extent, and the latter is a function of population, structure and content property value, damage probability, and percent of property damaged. Results: Historical (1992−2015) average annual statewide property loss due to wildfire was $5,556,389 (2010$), with the greatest risk to wildfire in southwestern inland, east-central, extreme northw...
The land-water interface is of great importance due to its significance in resource extraction, c... more The land-water interface is of great importance due to its significance in resource extraction, coastal management and climate change vulnerability analysis. In the recent years, determination of shoreline requires more concern as the coast of Bangladesh is vulnerable to anticipated sea level rise due to climate change. Region specific shoreline determination is needed for resource extraction, coastal risk management and landuse planning. This report is produced to address the areas of erosion, accretion and stable shoreline along the coast of Kuakata for providing a basis to describe the extent of economic and environmental effects of present shore erosion and accretion. In this study, the shoreline change is primarily detected for three decades by comparing satellite imagery of 1989, 2003 and 2010, using Landsat TM 30m resolution images. Band Combination, Ratio Transformation, Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) algorithms are...
Louisiana, U.S.A., is among the world's most vulnerable places to coastal flooding. Increasin... more Louisiana, U.S.A., is among the world's most vulnerable places to coastal flooding. Increasing frequency/intensity of natural hazards under climate change scenarios is expected to exacerbate Louisiana's coastal flood risk. Although many factors are involved, land subsidence from marshland compaction and underground resource extraction, shoreline erosion accelerated by eustatic sea level rise (ESLR), and tropical-cyclone-induced storm surge are among the most important. While past research has focused on flood risk assessment and mitigation strategies, including climate change scenarios, few studies examine all of these factors collectively. This study shows present pluvial flood depth and the contributions of additional coastal subsidence and ESLR toward future (2050) pluvial flooding. Then, current tropical-storm-induced storm surge and future storm surge depth modeled by Louisiana's Coastal Protection and Restoration Authority (CPRA) under climate change scenarios are ...
Sinkholes (or dolines) are an often-overlooked environmental hazard. The processes that lead to t... more Sinkholes (or dolines) are an often-overlooked environmental hazard. The processes that lead to their formation are slow and insidious, which encourage a lack of awareness or concern for the potential danger, until the sudden, climactic formation leads to unexpected property damage and possibly human casualties. This research identifies the risk to residential properties to the sinkhole hazard, using Louisiana, United States as a case study. Risk is defined as the product of the hazard intensity and the loss to structure and contents within the building resulting from the hazard-related disaster. Results suggest that risk is highly scale-dependent. Although the risk due to sinkholes is small on a per capita basis statewide, especially when compared to the per capita risk of other natural hazards, the property risk for census tracts or census blocks partially or completely overlying a salt dome is substantial. At finer scales, Terrebonne Parish, in coastal southeastern Louisiana, has...
In recent years, shoreline determination has become an issue of increasing importance and concern... more In recent years, shoreline determination has become an issue of increasing importance and concern, especially at the local level, as sea level continues to rise. This study identifies the rates of absolute and net erosion, accretion, and shoreline stabilization along the coast of Kuakata, a vulnerable coastal region in south-central Bangladesh. Shoreline change was detected by applying remote sensing and geographic information system (RS-GIS)-based techniques by using Landsat Thematic Mapper (TM), Landsat 8 Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) satellite images at 30-m resolution from 1989, 2003, 2010, and 2020. The band combination (BC) method was used to extract the shoreline (i.e., land-water boundary) due to its improved accuracy over other methods for matching with the existing shoreline position. This study also used participatory rural appraisal (PRA) tools which revealed the societal impacts caused by the shoreline changes. Coupling RS-GIS and PRA ...
Leading flood loss estimation models include Federal Emergency Management Agency’s (FEMA’s) Hazus... more Leading flood loss estimation models include Federal Emergency Management Agency’s (FEMA’s) Hazus, FEMA’s Flood Assessment Structure Tool (FAST), and (U.S.) Hydrologic Engineering Center’s Flood Impact Analysis (HEC-FIA), with each requiring different data input. No research to date has compared the resulting outcomes from such models at a neighborhood scale. This research examines the building and content loss estimates by Hazus Level 2, FAST, and HEC-FIA, over a levee-protected census block in Metairie, in Jefferson Parish, Louisiana. Building attribute data in National Structure Inventory (NSI) 2.0 are compared against “best available data” (BAD) collected at the individual building scale from Google Street View, Jefferson Parish building inventory, and 2019 National Building Cost Manual, to assess the sensitivity of input building inventory selection. Results suggest that use of BAD likely enhances flood loss estimation accuracy over existing reliance on default data in the soft...
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