Natural disasters often leave profound impacts on the environment. Existing disaster impact asses... more Natural disasters often leave profound impacts on the environment. Existing disaster impact assessment methods fall short in facilitating the relief work and in conducting cross-sectional comparison of various facets of such impacts. The development of a standardized index for measuring/monitoring the environmental impacts of disasters is necessary to address this gap. This paper proposes a conceptual framework to study the environmental impacts via remote sensing/GIS based geospatial analytical approach by developing a post-disaster environmental severity index. It considers physical, social and built-in components of the environment and identifies several key indicators of disaster impacts. Through statistical decomposition of a large number of environmental impact indicators, the study proposes a composite post-disaster environmental severity index (PDESI). Mapping of the proposed index would help identification of areas and component of the environment that are severely affected...
Abstract. Assessing urban vulnerability to natural hazards such as earthquakes can be regarded as... more Abstract. Assessing urban vulnerability to natural hazards such as earthquakes can be regarded as an ill-structured problem (i.e. a problem for which there is no unique, identifiable, objectively optimal solution). A review of the literature indicates a number of contrasting definitions of what vulnerability means, as well as numerous conflicting perspectives on what should or should not be included within the broad assessment of vulnerability in cities. This paper reports on the findings from a project in which a GIS methodology has been developed to assess urban vulnerability through a spatial analytical procedure. First, we highlight the deficiencies of current GIS approaches to urban vulnerability analysis and discuss the ill-structured nature of the vulnerability problem. We then propose a working definition for vulnerability assessment in which vulnerability is thought of as a spatial decision problem under the conditions of uncertainty. Next, we present a methodology to incor...
August 1, 2007 17:42 Wiley/IGR Page-199 c09 9 An integrative GIS and remote sensing model for pla... more August 1, 2007 17:42 Wiley/IGR Page-199 c09 9 An integrative GIS and remote sensing model for place-based urban vulnerability analysis Tarek Rashed,∗ John Weeks,† Helen Couclelis‡ and Martin Herold§ ∗Department of Geography, University of Oklahoma, Norman, OK, USA †Department of Geography, San Diego University, CA, USA ‡Department of Geography, University of California at Santa Barbara, CA, USA §Institut für Geographie, Friedrich-Schiller-Universität Jena, Germany
Since January 2020 Elsevier has created a COVID-19 resource centre with free information in Engli... more Since January 2020 Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre -including this research content -immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.
International Journal of Gender and Entrepreneurship, 2021
Purpose The study aims to co-create a “priority action roadmap for women's economic empowerme... more Purpose The study aims to co-create a “priority action roadmap for women's economic empowerment” based on women's top priorities to charting recovery directions. Doing so contributes to the growing body of knowledge on COVID-19 literature in at least four areas: assessing COVID-19 impacts on women entrepreneurs; mapping these impacts with four interdependent women's entrepreneurial ecosystem components; innovating a co-creation methodology based on remote participatory research; and providing a replicable model to perform action-oriented research in the context of COVID-19 impacts. Design/methodology/approach A co-creation methodology is proposed, combining systems-thinking and remote participatory research to engage women entrepreneurs and institutional stakeholders to prioritize impact, response actions and recovery needs in the wake of COVID-19. A ranking exercise using the analytic hierarchy process was used to derive ranking and assess user inputs' consistency. ...
Abstract Although vulnerability represents an essential concept in the development of mitigation ... more Abstract Although vulnerability represents an essential concept in the development of mitigation strategies at the local, national, and international levels, there is little consensus among researchers, planners, and disaster managers regarding the best way to ...
This paper discusses the implementation of an integrated set of methods used to explore the relat... more This paper discusses the implementation of an integrated set of methods used to explore the relative importance of the social characteristics and the physical conditions of urban morphology in shaping the spatial patterns of urban vulnerability to earthquake hazards in Los Angeles County. These methods include: (1) the development of an index for social vulnerability at the census tract level based on the 1990 population census, (2) the normalization of remotely sensed measures that describe the composition of census tracts in terms of the fractional abundance of urban land cover extracted through the spectral mixture analysis of a Landsat Thematic Mapper (TM) image, (3) the utilization of landscape pattern metrics for deriving new variables that describe the urban spatial structure of census tracts based on urban land cover fractions, and (4) the use of a spatial filtering technique to resolve the spatial autocorrelation problem among the independent variables. The paper begins wit...
This paper introduces an integrative methodology that has been developed to measure temporal chan... more This paper introduces an integrative methodology that has been developed to measure temporal changes in urban morphology based on the techniques of multiple endmember spectral mixture analysis (MESMA), landscape metrics, and fuzzy logic. In order to illustrate an application of the methodology, the paper uses two satellite images acquired in 1990 and 2000 for the metropolitan area of Los Angeles County, California, a megacity with complex morphological patterns that are rapidly changing due to a range of complex, interrelated forces of urbanization that are poorly understood. Through a wall-to-wall exercise, the paper discusses: (1) how the spatially continuous character of urban morphology in Los Angeles has been analyzed through the MESMA technique to capture and quantify within-class changes at the sub-pixel level; (2) how the magnitudes of changes have been assessed through fuzzy logic; and (3) how landscape metrics have been applied to quantify the ecological patterns of change...
This study has applied an integrated airborne laser scanning (ALS) and geographic information sys... more This study has applied an integrated airborne laser scanning (ALS) and geographic information systems (GIS) technique to estimate urban tree damages caused by an ice storm that affected the City of Norman, Oklahoma between 8 and 11th of December, 2007. Pre-and post-storm ALS data were collected and processed using GIS. The pre-storm ALS data was used to create a digital elevation model (DEM) and the pre-storm digital surface model (DSM) while the post-storm DSM was created from post-storm ALS data. The DEM were subtracted from the two DSMs to create the pre-and post-storm canopy height models (CHMs). Individual and grouped trees were then separated using a combination of Koukoulas and Blackburn and local maxima tree extraction algorithms. Finally, differences in height and canopy diameter between the pre-and post-storm CHMs within the extracted trees were calculated to measure the damage. Results showed that approximately 9% of the urban trees were completely damaged while almost 6% did not sustain any damage. It also showed that tree damage from ice storms varied with species and that Acer saccarinum, Acer saccharum Marsh, Ulmus americana, and Ulmus pumila were most vulnerable while Platanus occidentalis and Quercus palustris were the most resilient tree species to the ice storm. When compared with the ground reference data, it was found that the proposed methodology can detect tree height/stem damage with >81% accuracy compared to >42% accuracy in canopy damage assessment. Once ALS data is collected after a disaster, the methodology can provide a quick estimate of urban tree damage and hence be useful for city planners. It can also be used to create detailed inventories of tree heights of urban forests and monitor their growth and changes to improve their long-term sustainability.
Accurate pesticide exposure estimation is integral to epidemiologic studies elucidating the role ... more Accurate pesticide exposure estimation is integral to epidemiologic studies elucidating the role of pesticides in human health. Humans can be exposed to pesticides via residential proximity to agricultural pesticide applications (drift). We present an improved geographic information system (GIS) and remote sensing method, the Landsat method, to estimate agricultural pesticide exposure through matching pesticide applications to crops classified from temporally concurrent Landsat satellite remote sensing images in California. The image classification method utilizes Normalized Difference Vegetation Index (NDVI) values in a combined maximum likelihood classification and per-field (using segments) approach. Pesticide exposure is estimated according to pesticide-treated crop fields intersecting 500 m buffers around geocoded locations (e.g., residences) in a GIS. Study results demonstrate that the Landsat method can improve GIS-based pesticide exposure estimation by matching more pesticide applications to crops (especially temporary crops) classified using temporally concurrent Landsat images compared to the standard method that relies on infrequently updated land use survey (LUS) crop data. The Landsat method can be used in epidemiologic studies to reconstruct past individual-level exposure to specific pesticides according to where individuals are located.
ABSTRACT This chapter focuses on techniques related to image fusion and data fusion from differen... more ABSTRACT This chapter focuses on techniques related to image fusion and data fusion from different sources with varying spatial and spectral resolutions, and presents and discusses some of the technical issues that influence data fusion in the urban context.
Two conceptual models for urban neighborhood change and urban landscape ecology are used to devis... more Two conceptual models for urban neighborhood change and urban landscape ecology are used to devise an integrative methodology for measuring temporal changes in the urban morphology of Los Angeles, California, based on the techniques of multiple endmember spectral mixture analysis (MESMA), landscape metrics, and fuzzy logic. To illustrate an application of the methodology, the research utilizes two Landsat Thematic Mapper images acquired in 1990 and 2000. Through a wall-to-wall exercise, the paper discusses: (1) how the spatially continuous character of the urban morphology in Los Angeles is analyzed through the use of MESMA technique to capture and quantify within-class changes in land cover at the sub-pixel level; (2) how the magnitude of land cover changes is assessed through fuzzy logic; and (3) how landscape metrics are applied to quantify patterns of change in land cover at the census tract level. The results of the case study indicate that the integration of MESMA, fuzzy logic and landscape metrics can provide a systematic way to derive comparable measures of change in urban neighborhoods in Los Angeles. Further research is however needed to develop more rigorous methods for assessing the accuracy of land cover fractions generated by MESMA. The paper concludes with a discussion of how the proposed methodology may present a step towards a closer integration of remote sensing technology into the reformation of planning policies concerning urban sustainable development.
Natural disasters often leave profound impacts on the environment. Existing disaster impact asses... more Natural disasters often leave profound impacts on the environment. Existing disaster impact assessment methods fall short in facilitating the relief work and in conducting cross-sectional comparison of various facets of such impacts. The development of a standardized index for measuring/monitoring the environmental impacts of disasters is necessary to address this gap. This paper proposes a conceptual framework to study the environmental impacts via remote sensing/GIS based geospatial analytical approach by developing a post-disaster environmental severity index. It considers physical, social and built-in components of the environment and identifies several key indicators of disaster impacts. Through statistical decomposition of a large number of environmental impact indicators, the study proposes a composite post-disaster environmental severity index (PDESI). Mapping of the proposed index would help identification of areas and component of the environment that are severely affected...
Abstract. Assessing urban vulnerability to natural hazards such as earthquakes can be regarded as... more Abstract. Assessing urban vulnerability to natural hazards such as earthquakes can be regarded as an ill-structured problem (i.e. a problem for which there is no unique, identifiable, objectively optimal solution). A review of the literature indicates a number of contrasting definitions of what vulnerability means, as well as numerous conflicting perspectives on what should or should not be included within the broad assessment of vulnerability in cities. This paper reports on the findings from a project in which a GIS methodology has been developed to assess urban vulnerability through a spatial analytical procedure. First, we highlight the deficiencies of current GIS approaches to urban vulnerability analysis and discuss the ill-structured nature of the vulnerability problem. We then propose a working definition for vulnerability assessment in which vulnerability is thought of as a spatial decision problem under the conditions of uncertainty. Next, we present a methodology to incor...
August 1, 2007 17:42 Wiley/IGR Page-199 c09 9 An integrative GIS and remote sensing model for pla... more August 1, 2007 17:42 Wiley/IGR Page-199 c09 9 An integrative GIS and remote sensing model for place-based urban vulnerability analysis Tarek Rashed,∗ John Weeks,† Helen Couclelis‡ and Martin Herold§ ∗Department of Geography, University of Oklahoma, Norman, OK, USA †Department of Geography, San Diego University, CA, USA ‡Department of Geography, University of California at Santa Barbara, CA, USA §Institut für Geographie, Friedrich-Schiller-Universität Jena, Germany
Since January 2020 Elsevier has created a COVID-19 resource centre with free information in Engli... more Since January 2020 Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre -including this research content -immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.
International Journal of Gender and Entrepreneurship, 2021
Purpose The study aims to co-create a “priority action roadmap for women's economic empowerme... more Purpose The study aims to co-create a “priority action roadmap for women's economic empowerment” based on women's top priorities to charting recovery directions. Doing so contributes to the growing body of knowledge on COVID-19 literature in at least four areas: assessing COVID-19 impacts on women entrepreneurs; mapping these impacts with four interdependent women's entrepreneurial ecosystem components; innovating a co-creation methodology based on remote participatory research; and providing a replicable model to perform action-oriented research in the context of COVID-19 impacts. Design/methodology/approach A co-creation methodology is proposed, combining systems-thinking and remote participatory research to engage women entrepreneurs and institutional stakeholders to prioritize impact, response actions and recovery needs in the wake of COVID-19. A ranking exercise using the analytic hierarchy process was used to derive ranking and assess user inputs' consistency. ...
Abstract Although vulnerability represents an essential concept in the development of mitigation ... more Abstract Although vulnerability represents an essential concept in the development of mitigation strategies at the local, national, and international levels, there is little consensus among researchers, planners, and disaster managers regarding the best way to ...
This paper discusses the implementation of an integrated set of methods used to explore the relat... more This paper discusses the implementation of an integrated set of methods used to explore the relative importance of the social characteristics and the physical conditions of urban morphology in shaping the spatial patterns of urban vulnerability to earthquake hazards in Los Angeles County. These methods include: (1) the development of an index for social vulnerability at the census tract level based on the 1990 population census, (2) the normalization of remotely sensed measures that describe the composition of census tracts in terms of the fractional abundance of urban land cover extracted through the spectral mixture analysis of a Landsat Thematic Mapper (TM) image, (3) the utilization of landscape pattern metrics for deriving new variables that describe the urban spatial structure of census tracts based on urban land cover fractions, and (4) the use of a spatial filtering technique to resolve the spatial autocorrelation problem among the independent variables. The paper begins wit...
This paper introduces an integrative methodology that has been developed to measure temporal chan... more This paper introduces an integrative methodology that has been developed to measure temporal changes in urban morphology based on the techniques of multiple endmember spectral mixture analysis (MESMA), landscape metrics, and fuzzy logic. In order to illustrate an application of the methodology, the paper uses two satellite images acquired in 1990 and 2000 for the metropolitan area of Los Angeles County, California, a megacity with complex morphological patterns that are rapidly changing due to a range of complex, interrelated forces of urbanization that are poorly understood. Through a wall-to-wall exercise, the paper discusses: (1) how the spatially continuous character of urban morphology in Los Angeles has been analyzed through the MESMA technique to capture and quantify within-class changes at the sub-pixel level; (2) how the magnitudes of changes have been assessed through fuzzy logic; and (3) how landscape metrics have been applied to quantify the ecological patterns of change...
This study has applied an integrated airborne laser scanning (ALS) and geographic information sys... more This study has applied an integrated airborne laser scanning (ALS) and geographic information systems (GIS) technique to estimate urban tree damages caused by an ice storm that affected the City of Norman, Oklahoma between 8 and 11th of December, 2007. Pre-and post-storm ALS data were collected and processed using GIS. The pre-storm ALS data was used to create a digital elevation model (DEM) and the pre-storm digital surface model (DSM) while the post-storm DSM was created from post-storm ALS data. The DEM were subtracted from the two DSMs to create the pre-and post-storm canopy height models (CHMs). Individual and grouped trees were then separated using a combination of Koukoulas and Blackburn and local maxima tree extraction algorithms. Finally, differences in height and canopy diameter between the pre-and post-storm CHMs within the extracted trees were calculated to measure the damage. Results showed that approximately 9% of the urban trees were completely damaged while almost 6% did not sustain any damage. It also showed that tree damage from ice storms varied with species and that Acer saccarinum, Acer saccharum Marsh, Ulmus americana, and Ulmus pumila were most vulnerable while Platanus occidentalis and Quercus palustris were the most resilient tree species to the ice storm. When compared with the ground reference data, it was found that the proposed methodology can detect tree height/stem damage with >81% accuracy compared to >42% accuracy in canopy damage assessment. Once ALS data is collected after a disaster, the methodology can provide a quick estimate of urban tree damage and hence be useful for city planners. It can also be used to create detailed inventories of tree heights of urban forests and monitor their growth and changes to improve their long-term sustainability.
Accurate pesticide exposure estimation is integral to epidemiologic studies elucidating the role ... more Accurate pesticide exposure estimation is integral to epidemiologic studies elucidating the role of pesticides in human health. Humans can be exposed to pesticides via residential proximity to agricultural pesticide applications (drift). We present an improved geographic information system (GIS) and remote sensing method, the Landsat method, to estimate agricultural pesticide exposure through matching pesticide applications to crops classified from temporally concurrent Landsat satellite remote sensing images in California. The image classification method utilizes Normalized Difference Vegetation Index (NDVI) values in a combined maximum likelihood classification and per-field (using segments) approach. Pesticide exposure is estimated according to pesticide-treated crop fields intersecting 500 m buffers around geocoded locations (e.g., residences) in a GIS. Study results demonstrate that the Landsat method can improve GIS-based pesticide exposure estimation by matching more pesticide applications to crops (especially temporary crops) classified using temporally concurrent Landsat images compared to the standard method that relies on infrequently updated land use survey (LUS) crop data. The Landsat method can be used in epidemiologic studies to reconstruct past individual-level exposure to specific pesticides according to where individuals are located.
ABSTRACT This chapter focuses on techniques related to image fusion and data fusion from differen... more ABSTRACT This chapter focuses on techniques related to image fusion and data fusion from different sources with varying spatial and spectral resolutions, and presents and discusses some of the technical issues that influence data fusion in the urban context.
Two conceptual models for urban neighborhood change and urban landscape ecology are used to devis... more Two conceptual models for urban neighborhood change and urban landscape ecology are used to devise an integrative methodology for measuring temporal changes in the urban morphology of Los Angeles, California, based on the techniques of multiple endmember spectral mixture analysis (MESMA), landscape metrics, and fuzzy logic. To illustrate an application of the methodology, the research utilizes two Landsat Thematic Mapper images acquired in 1990 and 2000. Through a wall-to-wall exercise, the paper discusses: (1) how the spatially continuous character of the urban morphology in Los Angeles is analyzed through the use of MESMA technique to capture and quantify within-class changes in land cover at the sub-pixel level; (2) how the magnitude of land cover changes is assessed through fuzzy logic; and (3) how landscape metrics are applied to quantify patterns of change in land cover at the census tract level. The results of the case study indicate that the integration of MESMA, fuzzy logic and landscape metrics can provide a systematic way to derive comparable measures of change in urban neighborhoods in Los Angeles. Further research is however needed to develop more rigorous methods for assessing the accuracy of land cover fractions generated by MESMA. The paper concludes with a discussion of how the proposed methodology may present a step towards a closer integration of remote sensing technology into the reformation of planning policies concerning urban sustainable development.
Uploads
Papers by Tarek Rashed