The body of scientific literature on slum mapping employing remote sensing methods has increased ... more The body of scientific literature on slum mapping employing remote sensing methods has increased since the availability of more very-high-resolution (VHR) sensors. This improves the ability to produce information for pro-poor policy development and to build methods capable of supporting systematic global slum monitoring required for international policy development such as the Sustainable Development Goals. This review provides an overview of slum mapping-related remote sensing publications over the period of 2000-2015 regarding four dimensions: contextual factors, physical slum characteristics, data and requirements, and slum extraction methods. The review has shown the following results. First, our contextual knowledge on the diversity of slums across the globe is limited, and slum dynamics are not well captured. Second, a more systematic exploration of physical slum characteristics is required for the development of robust image-based proxies. Third, although the latest commercial sensor technologies provide image data of less than 0.5 m spatial resolution, thereby improving object recognition in slums, the complex and diverse morphology of slums makes extraction through standard methods difficult. Fourth, successful approaches show diversity in terms of extracted information levels (area or object based), implemented indicator sets (single or large sets) and methods employed (e.g., object-based image analysis (OBIA) or machine learning). In the context of a global slum inventory, texture-based methods show good robustness across cities and imagery. Machine-learning algorithms have the highest reported accuracies and allow working with large indicator sets in a computationally efficient manner, while the upscaling of pixel-level information requires further research. For local slum mapping, OBIA approaches show good capabilities of extracting both area-and object-based information. Ultimately, establishing a more systematic relationship between higher-level image elements and slum characteristics is essential to train algorithms able to analyze variations in slum morphologies to facilitate global slum monitoring.
The spatial monitoring of the urban expansion and related population growth is useful for urban p... more The spatial monitoring of the urban expansion and related population growth is useful for urban planning assessment of cities and megacities in the global South. Although market driven public programs for peri-urban low-income housing have retained much attention over the past twenty-five years in Mexico, a spatially explicit database of the consequent urban footprint together with the population census information has not been available online to the public. In this research, we build a geoscientific data collection consisting of: A built-up layer in 2000 and 2010 for the 10 major metropolitan areas of the Mexico Central Altiplano Region; A built-up layer in 2000 for the remaining 14 most prominent cities of the Mexican Urban System. A land consumption index at county (“Municipio”) level in the Mexico Central Altiplano Region. The Urban Footprint of Mexico is the first online national cartography incorporating built-up and demographic expansion.
In many cities and urban areas in Africa, land acquisition for urban redevelopment, land readjust... more In many cities and urban areas in Africa, land acquisition for urban redevelopment, land readjustment, and resettlement of affected urban residents are currently framed as innovative approaches to eradicating informal settlements, improving the living environments, and supporting the implementation of newly adopted city Master Plans. Nevertheless, it is not yet known how the responses of institutions and affected people shape these processes. Based on research conducted in Kigali, Rwanda, this article discusses affected residents’ responses to land expropriation and resettlement necessary for urban redevelopments. Our findings show that affected informal settlement dwellers voiced their concerns over the deviations from the Expropriation Law, compensation decision-making made behind closed doors, lack of transparency in property valuation, and compensation packages that they perceive to be unfair. Some of the consequences of these concerns are strong feelings of unfairness, exclusio...
International Journal of Applied Earth Observation and Geoinformation
In-situ slum upgrading projects include infrastructural improvements such as new roads, which are... more In-situ slum upgrading projects include infrastructural improvements such as new roads, which are perceived to improve the quality of life for the residents and encourage structural improvements at a household level. Although these physical changes are easily visible in satellite imagery, it is more difficult to track incremental improvements undertaken by the residentswhich are perhaps more closely linked to the socioeconomic development of the households themselves. The improved detail provided by imagery obtained from Unmanned Aerial Vehicles (UAVs) has the potential to monitor these more subtle changes in a settlement. This paper provides a framework which takes advantage of high-resolution imagery and a detailed elevation model from UAVs to detect changes in informal settlements. The proposed framework leverages expert knowledge to provide training labels for deep learning and thus avoids the cost of manual labelling. The semantic classification is then used to interpret a change mask and identify: new buildings, the creation of open spaces, and incremental roof upgrading in an informal settlement. The methodology is demonstrated on UAV imagery of an informal settlement in Kigali, Rwanda, successfully identifying changes between 2015 and 2017 with an Overall Accuracy of 95 % and correctly interpreting changes with an Overall Accuracy of 91 %. Results reveal that almost half the buildings in the settlement show visible changes in the roofing material, and 61 % of these changed less than 1m². This demonstrates the incremental nature of housing improvements in the settlement.
Peripheral urban sprawl configures new, extensive conurbations that transcend current administrat... more Peripheral urban sprawl configures new, extensive conurbations that transcend current administrative boundaries. Land use planning, supported by the analysis of future scenarios, is a guide to achieve sustainability in large metropolitan areas. To understand how urban sprawl is consuming natural and agricultural land, this paper analyzes land use changes in the metropolis of Quito, considering a combination of urban planning, natural conservation and risk areas. Using the Dyna-CLUE model we simulate spatial demands for future land uses by 2050, based on two growth scenarios: the trend scenario (unrestricted growth) and the regulated scenario, which considers two parameters—a government proposal for urban expansion areas and laws that protect natural areas. Both scenarios show how urban expansion consumes agricultural and natural areas. This expansion is backed by urban policies which do not sufficiently account for conservation areas nor for risk areas. Therefore, these simulations ...
International Journal of Safety and Security Engineering
Ground water scarcity is a main socio-ecological challenge in the Middle East. While ground water... more Ground water scarcity is a main socio-ecological challenge in the Middle East. While ground water reserves seem vast, the impacts of over-exploitation and inadequate control over water consumption may threaten the sustainability of aquifers. The signs of aquifer depletion and its influence on water accessibility have become apparent in recent years. Using the case of Rafsanjan Township, Iran, this study aims to understand the socio-ecological factors and their interrelationships in driving and exacerbating the water crisis situation, the ongoing policy responses and the possible consequences of current trends. The Drivers, Pressures, State, Impacts and Responses (DPSIR) framework, developed by the European Environmental Agency in 1999, is used to analyze the components of the socio-ecological system. Inputs are generated through a time series analysis of Landsat images, extracted spatial datasets, secondary literature and government reports. This study illustrates the conflict between rapid economic development policies that have simulated the expansion of pistachio orchards on the one hand and sustainable water resource management on the other. Some responses based on a long-term socio-ecological resilient planning approach may provide a more sustainable perspective, but will require a substantial rethinking of current policies, improved water management practices, and additional research.
Perceptions of seismic risks, among other factors, are influenced by urban environments. This rel... more Perceptions of seismic risks, among other factors, are influenced by urban environments. This relationship is investigated in this paper, in relation to open spaces. A comparative study of two communities in Kathmandu, Nepal with the context of 2015 earthquake was conducted using data gathered from household surveys and expert interviews. Escape behaviour in relation to open spaces was examined by analysing the correlation with a risk perception index (RPI) which is a novel approach in seismic risk perception studies. Additionally, point density analysis of surveyed houses and visualization of escape routes and destination followed by the respondents offer insights into the spatial relationship with perceived risk. Furthermore, expert interviews were used to validate the findings and highlight the important relationship between perceived risks and open spaces. The findings suggest that open spaces are a key component of disaster response as they are safe locations and offer spaces for community that enables mutual coping among its members. As such it directly or indirectly affect people’s perception of seismic risk. It was found that medium sized communal spaces are preferred within a distance of 200m as immediate safe destinations. The choices for such spaces are dependent on the built environment of the site given by its layout, landmarks, building density and building height. The choices of open spaces as shelter locations are influenced by duration of stay such as availability of drinking water, public lavatory and electricity are crucial for short term stay where as ownership and economic capabilities are vital for long term stay.
The survey-based slum mapping (SBSM) program conducted by the Indonesian government to reach the ... more The survey-based slum mapping (SBSM) program conducted by the Indonesian government to reach the national target of “cities without slums” by 2019 shows mapping inconsistencies due to several reasons, e.g., the dependency on the surveyor’s experiences and the complexity of the slum indicators set. By relying on such inconsistent maps, it will be difficult to monitor the national slum upgrading program’s progress. Remote sensing imagery combined with machine learning algorithms could support the reduction of these inconsistencies. This study evaluates the performance of two machine learning algorithms, i.e., support vector machine (SVM) and random forest (RF), for slum mapping in support of the slum mapping campaign in Bandung, Indonesia. Recognizing the complexity in differentiating slum and formal areas in Indonesia, the study used a combination of spectral, contextual, and morphological features. In addition, sequential feature selection (SFS) combined with the Hilbert–Schmidt ind...
In this study we demonstrate how to support policy option analysis for a problematic Social-Ecolo... more In this study we demonstrate how to support policy option analysis for a problematic Social-Ecological System (SES) with the help of stakeholder participation. SES sustainability problems 1) are highly complex, 2) may lack reliable data, 3) encompass conflicting interests and 4) may require contradictory management interventions. Our approach uses a structured participatory method combining the Driver-Pressure-State-Impact-Response (DPSIR) model together with Fuzzy Cognitive Mapping (FCM) to capture the complexity of the system and simplify its representation for simulation and policy option analysis. Using this novel mixed-method was useful in dealing with above-mentioned characteristics of the complex SES problems. The method was applied in a case study of water scarcity in Rafsanjan, Iran. FCMs were produced for 60 individual farmers and 40 individual researchers and policy makers. Our mixed-method analysis reveals similarities and differences of stakeholder knowledge and problem perception, and simulates the impacts of alternative policy options according to each group's perception. The final result of our case study indicates that farmers in Rafsanjan strongly believe in the impact of economic diversification on reducing water shortage, but they have a low level of trust in the ability of the government to regulate and control water usage, whereas the policy makers and researchers still believe in the role of government control and monitoring policies to deal with water scarcity in Rafsanjan.
Proceedings of Spie the International Society For Optical Engineering, Oct 1, 2009
This research analyzes the spatial pattern of large-scale stores based on space syntax theory and... more This research analyzes the spatial pattern of large-scale stores based on space syntax theory and explores the correlation between the variations in syntax accessibility and the spatial pattern of large-scale stores. This research develops a framework of spatial topology analysis based on the space syntax theory, which includes the following modifications: the trail to break the traditional long axial line network of space syntax and apply this partitioned network in the topological analysis; the trail to analyze the bus route network; By taking both the syntax accessibility of road and bus network into consideration, we produce the scopes of urban syntax centers of city level, local level and sub local level respectively. In the analysis of the retail distribution pattern, the city level, local level and sub local level urban retail centers are suggested respectively according to the spatial distributions of the quantity and scale of the retail stores. The spatial distribution pattern of each retail format is studied as spatial correlations between the retail locations and the urban space syntax centers based on a case study in Wuhan, China. The Space Syntax can be a useful tool to explain the allocation logic of urban retail space in large cities. We suggest to apply the partitioned transportation network instead of the traditional long axial line network.
Processes of globalization and neoliberal reforms of local governance in Indian cities have creat... more Processes of globalization and neoliberal reforms of local governance in Indian cities have created distinct patterns by reshaping the physical and social landscapes of India’s cities, triggering contestations between the privileged and the dispossessed. This paper addresses the consequences for poor households of mega-urban renewal and infrastructure projects and the processes of displacement and resettlement in Ahmedabad, India. The findings indicate that the displaced poor households have been further impoverished in the course of current practices as a result of limited attention to the risk of impoverishment both in policy and in local government practices. Contrary to the state’s rhetoric of inclusive governance, the urban poor are completely excluded from planning for infrastructure development and resettlement processes, leading to a lack of understanding of their needs by the state and their subsequent impoverishment after resettlement.
The body of scientific literature on slum mapping employing remote sensing methods has increased ... more The body of scientific literature on slum mapping employing remote sensing methods has increased since the availability of more very-high-resolution (VHR) sensors. This improves the ability to produce information for pro-poor policy development and to build methods capable of supporting systematic global slum monitoring required for international policy development such as the Sustainable Development Goals. This review provides an overview of slum mapping-related remote sensing publications over the period of 2000-2015 regarding four dimensions: contextual factors, physical slum characteristics, data and requirements, and slum extraction methods. The review has shown the following results. First, our contextual knowledge on the diversity of slums across the globe is limited, and slum dynamics are not well captured. Second, a more systematic exploration of physical slum characteristics is required for the development of robust image-based proxies. Third, although the latest commercial sensor technologies provide image data of less than 0.5 m spatial resolution, thereby improving object recognition in slums, the complex and diverse morphology of slums makes extraction through standard methods difficult. Fourth, successful approaches show diversity in terms of extracted information levels (area or object based), implemented indicator sets (single or large sets) and methods employed (e.g., object-based image analysis (OBIA) or machine learning). In the context of a global slum inventory, texture-based methods show good robustness across cities and imagery. Machine-learning algorithms have the highest reported accuracies and allow working with large indicator sets in a computationally efficient manner, while the upscaling of pixel-level information requires further research. For local slum mapping, OBIA approaches show good capabilities of extracting both area-and object-based information. Ultimately, establishing a more systematic relationship between higher-level image elements and slum characteristics is essential to train algorithms able to analyze variations in slum morphologies to facilitate global slum monitoring.
The spatial monitoring of the urban expansion and related population growth is useful for urban p... more The spatial monitoring of the urban expansion and related population growth is useful for urban planning assessment of cities and megacities in the global South. Although market driven public programs for peri-urban low-income housing have retained much attention over the past twenty-five years in Mexico, a spatially explicit database of the consequent urban footprint together with the population census information has not been available online to the public. In this research, we build a geoscientific data collection consisting of: A built-up layer in 2000 and 2010 for the 10 major metropolitan areas of the Mexico Central Altiplano Region; A built-up layer in 2000 for the remaining 14 most prominent cities of the Mexican Urban System. A land consumption index at county (“Municipio”) level in the Mexico Central Altiplano Region. The Urban Footprint of Mexico is the first online national cartography incorporating built-up and demographic expansion.
In many cities and urban areas in Africa, land acquisition for urban redevelopment, land readjust... more In many cities and urban areas in Africa, land acquisition for urban redevelopment, land readjustment, and resettlement of affected urban residents are currently framed as innovative approaches to eradicating informal settlements, improving the living environments, and supporting the implementation of newly adopted city Master Plans. Nevertheless, it is not yet known how the responses of institutions and affected people shape these processes. Based on research conducted in Kigali, Rwanda, this article discusses affected residents’ responses to land expropriation and resettlement necessary for urban redevelopments. Our findings show that affected informal settlement dwellers voiced their concerns over the deviations from the Expropriation Law, compensation decision-making made behind closed doors, lack of transparency in property valuation, and compensation packages that they perceive to be unfair. Some of the consequences of these concerns are strong feelings of unfairness, exclusio...
International Journal of Applied Earth Observation and Geoinformation
In-situ slum upgrading projects include infrastructural improvements such as new roads, which are... more In-situ slum upgrading projects include infrastructural improvements such as new roads, which are perceived to improve the quality of life for the residents and encourage structural improvements at a household level. Although these physical changes are easily visible in satellite imagery, it is more difficult to track incremental improvements undertaken by the residentswhich are perhaps more closely linked to the socioeconomic development of the households themselves. The improved detail provided by imagery obtained from Unmanned Aerial Vehicles (UAVs) has the potential to monitor these more subtle changes in a settlement. This paper provides a framework which takes advantage of high-resolution imagery and a detailed elevation model from UAVs to detect changes in informal settlements. The proposed framework leverages expert knowledge to provide training labels for deep learning and thus avoids the cost of manual labelling. The semantic classification is then used to interpret a change mask and identify: new buildings, the creation of open spaces, and incremental roof upgrading in an informal settlement. The methodology is demonstrated on UAV imagery of an informal settlement in Kigali, Rwanda, successfully identifying changes between 2015 and 2017 with an Overall Accuracy of 95 % and correctly interpreting changes with an Overall Accuracy of 91 %. Results reveal that almost half the buildings in the settlement show visible changes in the roofing material, and 61 % of these changed less than 1m². This demonstrates the incremental nature of housing improvements in the settlement.
Peripheral urban sprawl configures new, extensive conurbations that transcend current administrat... more Peripheral urban sprawl configures new, extensive conurbations that transcend current administrative boundaries. Land use planning, supported by the analysis of future scenarios, is a guide to achieve sustainability in large metropolitan areas. To understand how urban sprawl is consuming natural and agricultural land, this paper analyzes land use changes in the metropolis of Quito, considering a combination of urban planning, natural conservation and risk areas. Using the Dyna-CLUE model we simulate spatial demands for future land uses by 2050, based on two growth scenarios: the trend scenario (unrestricted growth) and the regulated scenario, which considers two parameters—a government proposal for urban expansion areas and laws that protect natural areas. Both scenarios show how urban expansion consumes agricultural and natural areas. This expansion is backed by urban policies which do not sufficiently account for conservation areas nor for risk areas. Therefore, these simulations ...
International Journal of Safety and Security Engineering
Ground water scarcity is a main socio-ecological challenge in the Middle East. While ground water... more Ground water scarcity is a main socio-ecological challenge in the Middle East. While ground water reserves seem vast, the impacts of over-exploitation and inadequate control over water consumption may threaten the sustainability of aquifers. The signs of aquifer depletion and its influence on water accessibility have become apparent in recent years. Using the case of Rafsanjan Township, Iran, this study aims to understand the socio-ecological factors and their interrelationships in driving and exacerbating the water crisis situation, the ongoing policy responses and the possible consequences of current trends. The Drivers, Pressures, State, Impacts and Responses (DPSIR) framework, developed by the European Environmental Agency in 1999, is used to analyze the components of the socio-ecological system. Inputs are generated through a time series analysis of Landsat images, extracted spatial datasets, secondary literature and government reports. This study illustrates the conflict between rapid economic development policies that have simulated the expansion of pistachio orchards on the one hand and sustainable water resource management on the other. Some responses based on a long-term socio-ecological resilient planning approach may provide a more sustainable perspective, but will require a substantial rethinking of current policies, improved water management practices, and additional research.
Perceptions of seismic risks, among other factors, are influenced by urban environments. This rel... more Perceptions of seismic risks, among other factors, are influenced by urban environments. This relationship is investigated in this paper, in relation to open spaces. A comparative study of two communities in Kathmandu, Nepal with the context of 2015 earthquake was conducted using data gathered from household surveys and expert interviews. Escape behaviour in relation to open spaces was examined by analysing the correlation with a risk perception index (RPI) which is a novel approach in seismic risk perception studies. Additionally, point density analysis of surveyed houses and visualization of escape routes and destination followed by the respondents offer insights into the spatial relationship with perceived risk. Furthermore, expert interviews were used to validate the findings and highlight the important relationship between perceived risks and open spaces. The findings suggest that open spaces are a key component of disaster response as they are safe locations and offer spaces for community that enables mutual coping among its members. As such it directly or indirectly affect people’s perception of seismic risk. It was found that medium sized communal spaces are preferred within a distance of 200m as immediate safe destinations. The choices for such spaces are dependent on the built environment of the site given by its layout, landmarks, building density and building height. The choices of open spaces as shelter locations are influenced by duration of stay such as availability of drinking water, public lavatory and electricity are crucial for short term stay where as ownership and economic capabilities are vital for long term stay.
The survey-based slum mapping (SBSM) program conducted by the Indonesian government to reach the ... more The survey-based slum mapping (SBSM) program conducted by the Indonesian government to reach the national target of “cities without slums” by 2019 shows mapping inconsistencies due to several reasons, e.g., the dependency on the surveyor’s experiences and the complexity of the slum indicators set. By relying on such inconsistent maps, it will be difficult to monitor the national slum upgrading program’s progress. Remote sensing imagery combined with machine learning algorithms could support the reduction of these inconsistencies. This study evaluates the performance of two machine learning algorithms, i.e., support vector machine (SVM) and random forest (RF), for slum mapping in support of the slum mapping campaign in Bandung, Indonesia. Recognizing the complexity in differentiating slum and formal areas in Indonesia, the study used a combination of spectral, contextual, and morphological features. In addition, sequential feature selection (SFS) combined with the Hilbert–Schmidt ind...
In this study we demonstrate how to support policy option analysis for a problematic Social-Ecolo... more In this study we demonstrate how to support policy option analysis for a problematic Social-Ecological System (SES) with the help of stakeholder participation. SES sustainability problems 1) are highly complex, 2) may lack reliable data, 3) encompass conflicting interests and 4) may require contradictory management interventions. Our approach uses a structured participatory method combining the Driver-Pressure-State-Impact-Response (DPSIR) model together with Fuzzy Cognitive Mapping (FCM) to capture the complexity of the system and simplify its representation for simulation and policy option analysis. Using this novel mixed-method was useful in dealing with above-mentioned characteristics of the complex SES problems. The method was applied in a case study of water scarcity in Rafsanjan, Iran. FCMs were produced for 60 individual farmers and 40 individual researchers and policy makers. Our mixed-method analysis reveals similarities and differences of stakeholder knowledge and problem perception, and simulates the impacts of alternative policy options according to each group's perception. The final result of our case study indicates that farmers in Rafsanjan strongly believe in the impact of economic diversification on reducing water shortage, but they have a low level of trust in the ability of the government to regulate and control water usage, whereas the policy makers and researchers still believe in the role of government control and monitoring policies to deal with water scarcity in Rafsanjan.
Proceedings of Spie the International Society For Optical Engineering, Oct 1, 2009
This research analyzes the spatial pattern of large-scale stores based on space syntax theory and... more This research analyzes the spatial pattern of large-scale stores based on space syntax theory and explores the correlation between the variations in syntax accessibility and the spatial pattern of large-scale stores. This research develops a framework of spatial topology analysis based on the space syntax theory, which includes the following modifications: the trail to break the traditional long axial line network of space syntax and apply this partitioned network in the topological analysis; the trail to analyze the bus route network; By taking both the syntax accessibility of road and bus network into consideration, we produce the scopes of urban syntax centers of city level, local level and sub local level respectively. In the analysis of the retail distribution pattern, the city level, local level and sub local level urban retail centers are suggested respectively according to the spatial distributions of the quantity and scale of the retail stores. The spatial distribution pattern of each retail format is studied as spatial correlations between the retail locations and the urban space syntax centers based on a case study in Wuhan, China. The Space Syntax can be a useful tool to explain the allocation logic of urban retail space in large cities. We suggest to apply the partitioned transportation network instead of the traditional long axial line network.
Processes of globalization and neoliberal reforms of local governance in Indian cities have creat... more Processes of globalization and neoliberal reforms of local governance in Indian cities have created distinct patterns by reshaping the physical and social landscapes of India’s cities, triggering contestations between the privileged and the dispossessed. This paper addresses the consequences for poor households of mega-urban renewal and infrastructure projects and the processes of displacement and resettlement in Ahmedabad, India. The findings indicate that the displaced poor households have been further impoverished in the course of current practices as a result of limited attention to the risk of impoverishment both in policy and in local government practices. Contrary to the state’s rhetoric of inclusive governance, the urban poor are completely excluded from planning for infrastructure development and resettlement processes, leading to a lack of understanding of their needs by the state and their subsequent impoverishment after resettlement.
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Papers by Richard Sliuzas