Mahmoud Mahmoud | James Cook University Brisbane (original) (raw)
Papers by Mahmoud Mahmoud
DISCLAIMER This document describes work undertaken as part of a programme of study at the Faculty... more DISCLAIMER This document describes work undertaken as part of a programme of study at the Faculty of Geo-Information Science and Earth Observation of the University of Twente. All views and opinions expressed therein remain the sole responsibility of the author, and do not necessarily represent those of the Faculty. i ABSTRACT Historical topographic maps are distinct sources of spatial information for hind-cast studies. They are acclaimed to be one of the most reliable legacy archives representing and describing geographic features prior to aerial photography and the present day satellite imagery. However, two major challenges are encountered in extracting information from these sources. These challenges are conceptual and technical emanating from scanning artefacts, inherent map complexity and analogousness, although information extraction has been manually done through digitizing, pixel-based methods and visual map analysis, which are time consuming and tedious. Hence, there is ur...
Oryx, 2019
Tropical forest regions in equatorial Africa are threatened with degradation, deforestation and b... more Tropical forest regions in equatorial Africa are threatened with degradation, deforestation and biodiversity loss as a result of land-cover change. We investigated historical land-cover dynamics in unprotected forested areas of the Littoral Region in south-western Cameroon during 1975–2017, to detect changes that may influence this important biodiversity and wildlife area. Processed Landsat imagery was used to map and monitor changes in land use and land cover. From 1975 to 2017 the area of high-value forest landscapes decreased by c. 420,000 ha, and increasing forest fragmentation caused a decline of c. 12% in the largest patch index. Conversely, disturbed vegetation, cleared areas and urban areas all expanded in extent, by 32% (c. 400,000 ha), 5.6% (c. 26,800 ha) and 6.6% (c. 78,631 ha), respectively. The greatest increase was in the area converted to oil palm plantations (c. 26,893 ha), followed by logging and land clearing (c. 34,838 ha), all of which were the major factors driv...
Tropical Conservation Science, 2017
The Cross River State Government in Nigeria is proposing to construct a ''Cross River Superhighwa... more The Cross River State Government in Nigeria is proposing to construct a ''Cross River Superhighway'' that would bisect critical remaining areas of tropical rainforest in south eastern Nigeria. We offer and evaluate two alternative routes to the superhighway that would be less damaging to forests, protected areas, and biological diversity. The first alternative we identified avoids intact forests entirely while seeking to benefit agriculture and existing settlements. The second alternative also avoids intact forests while incorporating existing paved and unpaved roads to limit construction costs. As currently proposed, the superhighway would be 260 km long, would intersect 115 km of intact forests or protected areas, and would cost an estimated US$2.5 billion to construct. Alternative Routes 1 and 2 are only slightly longer (290 and 353 km, respectively) and have markedly lower estimated construction costs (US$0.92 billion). Furthermore, the alternative routes would have negligible impacts on forests and protected areas and would be better aligned to benefit local communities and agriculture. We argue that alternative routings such as those we examined here could markedly reduce the economic and environmental costs, and potentially increase the socioeconomic benefits, for the proposed Cross River Superhighway.
Remote Sensing, 2016
This study analyzed the spatiotemporal pattern of settlement expansion in Abuja, Nigeria, one of ... more This study analyzed the spatiotemporal pattern of settlement expansion in Abuja, Nigeria, one of West Africa's fastest developing cities, using geoinformation and ancillary datasets. Three epochs of Land-use Land-cover (LULC) maps for 1986, 2001 and 2014 were derived from Landsat images using support vector machines (SVM). Accuracy assessment (AA) of the LULC maps based on the pixel count resulted in overall accuracy of 82%, 92% and 92%, while the AA derived from the error adjusted area (EAA) method stood at 69%, 91% and 91% for 1986, 2001 and 2014, respectively. Two major techniques for detecting changes in the LULC epochs involved the use of binary maps as well as a post-classification comparison approach. Quantitative spatiotemporal analysis was conducted to detect LULC changes with specific focus on the settlement development pattern of Abuja, the federal capital city (FCC) of Nigeria. Logical transitions to the urban category were modelled for predicting future scenarios for the year 2050 using the embedded land change modeler (LCM) in the IDRISI package. Based on the EAA, the result showed that urban areas increased by more than 11% between 1986 and 2001. In contrast, this value rose to 17% between 2001 and 2014. The LCM model projected LULC changes that showed a growing trend in settlement expansion, which might take over allotted spaces for green areas and agricultural land if stringent development policies and enforcement measures are not implemented. In conclusion, integrating geospatial technologies with ancillary datasets offered improved understanding of how urbanization processes such as increased imperviousness of such a magnitude could influence the urban microclimate through the alteration of natural land surface temperature. Urban expansion could also lead to increased surface runoff as well as changes in drainage geography leading to urban floods.
Frontiers in Ecology and Evolution, 2017
The tropical forests of Africa are experiencing unprecedented changes as a result of a rapid prol... more The tropical forests of Africa are experiencing unprecedented changes as a result of a rapid proliferation of roads and other infrastructure. These projects are dramatically increasing access to relatively unexploited regions, particularly in the greater Congo Basin. We highlight some of the most important new projects and describe in detail an ongoing debate about a particular proposed development, the Cross River Superhighway in Nigeria. The scale and pace of new transportation projects, and the profound environmental changes they could bring, underscore a dire need for proactive land-use planning, capacity building, and environmental assessment in the nations of Equatorial Africa. It is no exaggeration to suggest that, unless carefully managed to ensure sustainability, the spate of planned and ongoing projects could irreparably diminish the forests and wildlife populations of Africa's most biologically diverse regions.
For leaders, planners and people around the world facing uncertainty about actions to resolve our... more For leaders, planners and people around the world facing uncertainty about actions to resolve our planetary crises, we offer a concrete framework for action. We take the six core areas identified for urgent action by humanity from our 2019 paper in BioScience, World Scientists Warning of a Climate Emergency, and convert these into a framework for concrete solutions at six scales (household; community; city; state/province/district; nation; global) and on three timelines (2022-2026; by 2030; by 2050). Humanity is nearly out of road, and our challenges are now less technical or scientific than social, behavioral, political and economic. Leaders' challenges will also be to steer the ship of humanity into a steady future on a vanishingly short timeline. All we know and love is at stake.
Science Progress, 2021
We have kicked the can down the road once againbut we are running out of road.'-Rachel Kyte, Dean... more We have kicked the can down the road once againbut we are running out of road.'-Rachel Kyte, Dean of Fletcher School at Tufts University. We, in our capacities as scientists, economists, governance and policy specialists, are shifting from warnings to guidance for action before there is no more 'road.' The science is clear and irrefutable; humanity is in advanced ecological overshoot. Our overexploitation of resources exceeds ecosystems' capacity to provide them or to absorb our waste. Society has failed to meet clearly stated goals of the UN Framework Convention on Climate Change. Civilization faces an epochal crossroads, but with potentially much better, wiser outcomes if we act now. What are the concrete and transformative actions by which we can turn away from the abyss? In this paper we forcefully recommend priority actions and resource allocation to avert the worst of the climate and nature emergencies, two of the most pressing symptoms of overshoot, and lead society into a future of greater wellbeing and wisdom. Humanity has begun the social, economic, political and technological initiatives needed for this transformation. Now, massive upscaling and acceleration of these actions and collaborations are essential before irreversible tipping points are crossed in the coming decade. We still can overcome significant societal, political and economic barriers of our own making. Previously, we identified six core areas for urgent global actionenergy, pollutants, nature, food systems, population stabilization and economic goals. Here we identify an indicative, systemic and time-limited framework for priority actions for policy, planning and management at multiple scales from household to global. We broadly follow the 'Reduce-Remove-Repair' approach to rapid action. To guide decision makers, planners, managers, and budgeters, we cite some of the many experiments, mechanisms and resources in order to facilitate rapid global adoption of effective solutions. Our biggest challenges are not technical, but social, economic, political and behavioral. To have hope of success, we must accelerate collaborative actions across scales, in different cultures and governance systems, while maintaining adequate social, economic and political stability. Effective and timely actions are still achievable on many, though not all fronts. Such change will mean the difference for billions of children and adults, hundreds of thousands of species, health of many ecosystems, and will determine our common future. *Phoebe Barnard and William Moomaw co-led the paper; other authors are listed in alphabetical order.
Current biology : CB, Jan 23, 2017
It is projected that 25 million km of new paved roads will be developed globally by 2050 - enough... more It is projected that 25 million km of new paved roads will be developed globally by 2050 - enough to encircle the planet more than 600 times. Roughly 90% of new roads will be built in developing nations, frequently in tropical and subtropical regions with high biodiversity and environmental values. Many developing nations are borrowing from international lenders or negotiating access to their natural resources in order to expand their transportation infrastructure. Given the unprecedented pace and extent of these initiatives, it is vital to thoroughly assess the potential consequences of large-scale road and highway projects. In appropriate contexts and locales, new roads can promote sizeable economic and social benefits. If poorly planned or implemented, however, new roads can provoke serious cost overruns, corruption and environmental impacts, while generating sparse economic benefits and intense social and political conflict. Using examples from developing nations, we identify ri...
World Scientists' Warning to Humanity: A Second No, 2017
Twenty-five years ago, the Union of Concerned Scientists and more than 1500 independent scientist... more Twenty-five years ago, the Union of Concerned Scientists and more than 1500 independent scientists, including the majority of living Nobel laureates in the sciences, penned the 1992 “World Scientists’ Warning to Humanity” (see supplemental materials). These concerned professionals called on humankind to curtail environmental destruction and cautioned that “a great change in our stewardship of the Earth and the life on it is required, if vast human misery is to be avoided.” In their manifesto, they showed that humans were on a collision course with the natural world. They expressed concern about current, impending, or potential damage on planet Earth involving ozone depletion, freshwater availability, marine fishery collapses, ocean dead zones, forest loss, biodiversity destruction, climate change, and continued human population growth. They proclaimed that fundamental changes were urgently needed to avoid the consequences our present course would bring.
The tropical forests of Africa are experiencing unprecedented changes as a result of a rapid prol... more The tropical forests of Africa are experiencing unprecedented changes as a result of a rapid proliferation of roads and other infrastructure. These projects are dramatically increasing access to relatively unexploited regions, particularly in the greater Congo Basin. We highlight some of the most important new projects and describe in detail an ongoing debate about a particular proposed development, the Cross River Superhighway in Nigeria. The scale and pace of new transportation projects, and the profound environmental changes they could bring, underscore a dire need for proactive land-use planning, capacity building, and environmental assessment in the nations of Equatorial Africa. It is no exaggeration to suggest that, unless carefully managed to ensure sustainability, the spate of planned and ongoing projects could irreparably diminish the forests and wildlife populations of Africa's most biologically diverse regions.
The Cross River State Government in Nigeria is proposing to construct a ''Cross River Superhighwa... more The Cross River State Government in Nigeria is proposing to construct a ''Cross River Superhighway'' that would bisect critical remaining areas of tropical rainforest in south eastern Nigeria. We offer and evaluate two alternative routes to the superhighway that would be less damaging to forests, protected areas, and biological diversity. The first alternative we identified avoids intact forests entirely while seeking to benefit agriculture and existing settlements. The second alternative also avoids intact forests while incorporating existing paved and unpaved roads to limit construction costs. As currently proposed, the superhighway would be 260 km long, would intersect 115 km of intact forests or protected areas, and would cost an estimated US$2.5 billion to construct. Alternative Routes 1 and 2 are only slightly longer (290 and 353 km, respectively) and have markedly lower estimated construction costs (US$0.92 billion). Furthermore, the alternative routes would have negligible impacts on forests and protected areas and would be better aligned to benefit local communities and agriculture. We argue that alternative routings such as those we examined here could markedly reduce the economic and environmental costs, and potentially increase the socioeconomic benefits, for the proposed Cross River Superhighway.
This study analyzed the spatiotemporal pattern of settlement expansion in Abuja, Nigeria, one of ... more This study analyzed the spatiotemporal pattern of settlement expansion in Abuja, Nigeria, one of West Africa's fastest developing cities, using geoinformation and ancillary datasets. Three epochs of Land-use Land-cover (LULC) maps for 1986, 2001 and 2014 were derived from Landsat images using support vector machines (SVM). Accuracy assessment (AA) of the LULC maps based on the pixel count resulted in overall accuracy of 82%, 92% and 92%, while the AA derived from the error adjusted area (EAA) method stood at 69%, 91% and 91% for 1986, 2001 and 2014, respectively. Two major techniques for detecting changes in the LULC epochs involved the use of binary maps as well as a post-classification comparison approach. Quantitative spatiotemporal analysis was conducted to detect LULC changes with specific focus on the settlement development pattern of Abuja, the federal capital city (FCC) of Nigeria. Logical transitions to the urban category were modelled for predicting future scenarios for the year 2050 using the embedded land change modeler (LCM) in the IDRISI package. Based on the EAA, the result showed that urban areas increased by more than 11% between 1986 and 2001. In contrast, this value rose to 17% between 2001 and 2014. The LCM model projected LULC changes that showed a growing trend in settlement expansion, which might take over allotted spaces for green areas and agricultural land if stringent development policies and enforcement measures are not implemented. In conclusion, integrating geospatial technologies with ancillary datasets offered improved understanding of how urbanization processes such as increased imperviousness of such a magnitude could influence the urban microclimate through the alteration of natural land surface temperature. Urban expansion could also lead to increased surface runoff as well as changes in drainage geography leading to urban floods.
Digital Elevation Models (DEMs) often provides inputs to natural hazard assessment and modeling. ... more Digital Elevation Models (DEMs) often provides inputs to natural hazard assessment and modeling. In the present work different DEM data sources and software’s were compared to generate Digital Terrain Model (DTM) outputs and their plausibility in different stages of natural hazard assessment and analysis. The Alvaro area of Basilicata of Italy was considered suitable for this study due to the terrain and hydrological processes going on in the area. The study required to integrate Remote sensing (RS), GIS techniques to inspect these different DEM sources viz a viz software outputs to assess their plausibility for hazard specific DTM parametizations and derivation. The resolutions of the DEM datasets from providers commonly differ and require critical assessment to determine their quality which might suggest their fitness for use for various natural hazard terrain and hydrodynamic modeling. To experiment on this and produce rational advice for users we used DEMs from SRTM, ASTER-GDEM, and contour derived DEM datasets. Integrated RS and GIS based procedures were implemented on these datasets using ArcGIS Spatial Analyst; ArcHydro in ArcGIS and ILWIS, software’s. The results revealed that DTM derivative differs from software to software which is a function of datasets characteristics. In view of this known premise it is necessary to critically assess DEM dataset with a variety of software before use to guide against false impression on DTM quality and fitness for use in decision making. After using ArcGIS and Ilwis we conclude that DEM hydro-processing modules in Ilwis software produce user controlled DEM derivatives for hydrodynamic modeling than in ArcGIS which is more of a black box processor.
Historical topographic maps are distinct sources of spatial information for hind-cast studies. Th... more Historical topographic maps are distinct sources of spatial information for hind-cast studies. They are acclaimed to be one of the most reliable legacy archives representing and describing geographic features prior to aerial photography and the present day satellite imagery. However, two major challenges are encountered in extracting information from these sources. These challenges are conceptual and technical emanating from scanning artefacts, inherent map complexity and analogousness, although information extraction has been manually done through digitizing, pixel-based methods and visual map analysis, which are time consuming and tedious. Hence, there is urgent need to explore robust and reliable methods such as the object-oriented analysis (OOA) to efficiently develop new information extraction techniques for scanned topographic paper maps. Therefore, this research investigated and answered questions about conceptualization, development, implementation and transferability of an OOA-based information extraction method for complex papers maps and potential applications.
Books by Mahmoud Mahmoud
The tropical forests of Central Africa sustain exceptionally high biodiversity and environmental ... more The tropical forests of Central Africa sustain exceptionally high biodiversity and environmental services such as forest hydrology and carbon storage. These forests span the Congo Basin and equatorial forests adjoining it. Like much of sub-Saharan Africa, this region facing dramatic changes in the number, extent, and environmental impacts of large-scale infrastructure projects. A particular concern is how such projects will affect important wildlife habitats, protected areas, and environmental services.
DISCLAIMER This document describes work undertaken as part of a programme of study at the Faculty... more DISCLAIMER This document describes work undertaken as part of a programme of study at the Faculty of Geo-Information Science and Earth Observation of the University of Twente. All views and opinions expressed therein remain the sole responsibility of the author, and do not necessarily represent those of the Faculty. i ABSTRACT Historical topographic maps are distinct sources of spatial information for hind-cast studies. They are acclaimed to be one of the most reliable legacy archives representing and describing geographic features prior to aerial photography and the present day satellite imagery. However, two major challenges are encountered in extracting information from these sources. These challenges are conceptual and technical emanating from scanning artefacts, inherent map complexity and analogousness, although information extraction has been manually done through digitizing, pixel-based methods and visual map analysis, which are time consuming and tedious. Hence, there is ur...
Oryx, 2019
Tropical forest regions in equatorial Africa are threatened with degradation, deforestation and b... more Tropical forest regions in equatorial Africa are threatened with degradation, deforestation and biodiversity loss as a result of land-cover change. We investigated historical land-cover dynamics in unprotected forested areas of the Littoral Region in south-western Cameroon during 1975–2017, to detect changes that may influence this important biodiversity and wildlife area. Processed Landsat imagery was used to map and monitor changes in land use and land cover. From 1975 to 2017 the area of high-value forest landscapes decreased by c. 420,000 ha, and increasing forest fragmentation caused a decline of c. 12% in the largest patch index. Conversely, disturbed vegetation, cleared areas and urban areas all expanded in extent, by 32% (c. 400,000 ha), 5.6% (c. 26,800 ha) and 6.6% (c. 78,631 ha), respectively. The greatest increase was in the area converted to oil palm plantations (c. 26,893 ha), followed by logging and land clearing (c. 34,838 ha), all of which were the major factors driv...
Tropical Conservation Science, 2017
The Cross River State Government in Nigeria is proposing to construct a ''Cross River Superhighwa... more The Cross River State Government in Nigeria is proposing to construct a ''Cross River Superhighway'' that would bisect critical remaining areas of tropical rainforest in south eastern Nigeria. We offer and evaluate two alternative routes to the superhighway that would be less damaging to forests, protected areas, and biological diversity. The first alternative we identified avoids intact forests entirely while seeking to benefit agriculture and existing settlements. The second alternative also avoids intact forests while incorporating existing paved and unpaved roads to limit construction costs. As currently proposed, the superhighway would be 260 km long, would intersect 115 km of intact forests or protected areas, and would cost an estimated US$2.5 billion to construct. Alternative Routes 1 and 2 are only slightly longer (290 and 353 km, respectively) and have markedly lower estimated construction costs (US$0.92 billion). Furthermore, the alternative routes would have negligible impacts on forests and protected areas and would be better aligned to benefit local communities and agriculture. We argue that alternative routings such as those we examined here could markedly reduce the economic and environmental costs, and potentially increase the socioeconomic benefits, for the proposed Cross River Superhighway.
Remote Sensing, 2016
This study analyzed the spatiotemporal pattern of settlement expansion in Abuja, Nigeria, one of ... more This study analyzed the spatiotemporal pattern of settlement expansion in Abuja, Nigeria, one of West Africa's fastest developing cities, using geoinformation and ancillary datasets. Three epochs of Land-use Land-cover (LULC) maps for 1986, 2001 and 2014 were derived from Landsat images using support vector machines (SVM). Accuracy assessment (AA) of the LULC maps based on the pixel count resulted in overall accuracy of 82%, 92% and 92%, while the AA derived from the error adjusted area (EAA) method stood at 69%, 91% and 91% for 1986, 2001 and 2014, respectively. Two major techniques for detecting changes in the LULC epochs involved the use of binary maps as well as a post-classification comparison approach. Quantitative spatiotemporal analysis was conducted to detect LULC changes with specific focus on the settlement development pattern of Abuja, the federal capital city (FCC) of Nigeria. Logical transitions to the urban category were modelled for predicting future scenarios for the year 2050 using the embedded land change modeler (LCM) in the IDRISI package. Based on the EAA, the result showed that urban areas increased by more than 11% between 1986 and 2001. In contrast, this value rose to 17% between 2001 and 2014. The LCM model projected LULC changes that showed a growing trend in settlement expansion, which might take over allotted spaces for green areas and agricultural land if stringent development policies and enforcement measures are not implemented. In conclusion, integrating geospatial technologies with ancillary datasets offered improved understanding of how urbanization processes such as increased imperviousness of such a magnitude could influence the urban microclimate through the alteration of natural land surface temperature. Urban expansion could also lead to increased surface runoff as well as changes in drainage geography leading to urban floods.
Frontiers in Ecology and Evolution, 2017
The tropical forests of Africa are experiencing unprecedented changes as a result of a rapid prol... more The tropical forests of Africa are experiencing unprecedented changes as a result of a rapid proliferation of roads and other infrastructure. These projects are dramatically increasing access to relatively unexploited regions, particularly in the greater Congo Basin. We highlight some of the most important new projects and describe in detail an ongoing debate about a particular proposed development, the Cross River Superhighway in Nigeria. The scale and pace of new transportation projects, and the profound environmental changes they could bring, underscore a dire need for proactive land-use planning, capacity building, and environmental assessment in the nations of Equatorial Africa. It is no exaggeration to suggest that, unless carefully managed to ensure sustainability, the spate of planned and ongoing projects could irreparably diminish the forests and wildlife populations of Africa's most biologically diverse regions.
For leaders, planners and people around the world facing uncertainty about actions to resolve our... more For leaders, planners and people around the world facing uncertainty about actions to resolve our planetary crises, we offer a concrete framework for action. We take the six core areas identified for urgent action by humanity from our 2019 paper in BioScience, World Scientists Warning of a Climate Emergency, and convert these into a framework for concrete solutions at six scales (household; community; city; state/province/district; nation; global) and on three timelines (2022-2026; by 2030; by 2050). Humanity is nearly out of road, and our challenges are now less technical or scientific than social, behavioral, political and economic. Leaders' challenges will also be to steer the ship of humanity into a steady future on a vanishingly short timeline. All we know and love is at stake.
Science Progress, 2021
We have kicked the can down the road once againbut we are running out of road.'-Rachel Kyte, Dean... more We have kicked the can down the road once againbut we are running out of road.'-Rachel Kyte, Dean of Fletcher School at Tufts University. We, in our capacities as scientists, economists, governance and policy specialists, are shifting from warnings to guidance for action before there is no more 'road.' The science is clear and irrefutable; humanity is in advanced ecological overshoot. Our overexploitation of resources exceeds ecosystems' capacity to provide them or to absorb our waste. Society has failed to meet clearly stated goals of the UN Framework Convention on Climate Change. Civilization faces an epochal crossroads, but with potentially much better, wiser outcomes if we act now. What are the concrete and transformative actions by which we can turn away from the abyss? In this paper we forcefully recommend priority actions and resource allocation to avert the worst of the climate and nature emergencies, two of the most pressing symptoms of overshoot, and lead society into a future of greater wellbeing and wisdom. Humanity has begun the social, economic, political and technological initiatives needed for this transformation. Now, massive upscaling and acceleration of these actions and collaborations are essential before irreversible tipping points are crossed in the coming decade. We still can overcome significant societal, political and economic barriers of our own making. Previously, we identified six core areas for urgent global actionenergy, pollutants, nature, food systems, population stabilization and economic goals. Here we identify an indicative, systemic and time-limited framework for priority actions for policy, planning and management at multiple scales from household to global. We broadly follow the 'Reduce-Remove-Repair' approach to rapid action. To guide decision makers, planners, managers, and budgeters, we cite some of the many experiments, mechanisms and resources in order to facilitate rapid global adoption of effective solutions. Our biggest challenges are not technical, but social, economic, political and behavioral. To have hope of success, we must accelerate collaborative actions across scales, in different cultures and governance systems, while maintaining adequate social, economic and political stability. Effective and timely actions are still achievable on many, though not all fronts. Such change will mean the difference for billions of children and adults, hundreds of thousands of species, health of many ecosystems, and will determine our common future. *Phoebe Barnard and William Moomaw co-led the paper; other authors are listed in alphabetical order.
Current biology : CB, Jan 23, 2017
It is projected that 25 million km of new paved roads will be developed globally by 2050 - enough... more It is projected that 25 million km of new paved roads will be developed globally by 2050 - enough to encircle the planet more than 600 times. Roughly 90% of new roads will be built in developing nations, frequently in tropical and subtropical regions with high biodiversity and environmental values. Many developing nations are borrowing from international lenders or negotiating access to their natural resources in order to expand their transportation infrastructure. Given the unprecedented pace and extent of these initiatives, it is vital to thoroughly assess the potential consequences of large-scale road and highway projects. In appropriate contexts and locales, new roads can promote sizeable economic and social benefits. If poorly planned or implemented, however, new roads can provoke serious cost overruns, corruption and environmental impacts, while generating sparse economic benefits and intense social and political conflict. Using examples from developing nations, we identify ri...
World Scientists' Warning to Humanity: A Second No, 2017
Twenty-five years ago, the Union of Concerned Scientists and more than 1500 independent scientist... more Twenty-five years ago, the Union of Concerned Scientists and more than 1500 independent scientists, including the majority of living Nobel laureates in the sciences, penned the 1992 “World Scientists’ Warning to Humanity” (see supplemental materials). These concerned professionals called on humankind to curtail environmental destruction and cautioned that “a great change in our stewardship of the Earth and the life on it is required, if vast human misery is to be avoided.” In their manifesto, they showed that humans were on a collision course with the natural world. They expressed concern about current, impending, or potential damage on planet Earth involving ozone depletion, freshwater availability, marine fishery collapses, ocean dead zones, forest loss, biodiversity destruction, climate change, and continued human population growth. They proclaimed that fundamental changes were urgently needed to avoid the consequences our present course would bring.
The tropical forests of Africa are experiencing unprecedented changes as a result of a rapid prol... more The tropical forests of Africa are experiencing unprecedented changes as a result of a rapid proliferation of roads and other infrastructure. These projects are dramatically increasing access to relatively unexploited regions, particularly in the greater Congo Basin. We highlight some of the most important new projects and describe in detail an ongoing debate about a particular proposed development, the Cross River Superhighway in Nigeria. The scale and pace of new transportation projects, and the profound environmental changes they could bring, underscore a dire need for proactive land-use planning, capacity building, and environmental assessment in the nations of Equatorial Africa. It is no exaggeration to suggest that, unless carefully managed to ensure sustainability, the spate of planned and ongoing projects could irreparably diminish the forests and wildlife populations of Africa's most biologically diverse regions.
The Cross River State Government in Nigeria is proposing to construct a ''Cross River Superhighwa... more The Cross River State Government in Nigeria is proposing to construct a ''Cross River Superhighway'' that would bisect critical remaining areas of tropical rainforest in south eastern Nigeria. We offer and evaluate two alternative routes to the superhighway that would be less damaging to forests, protected areas, and biological diversity. The first alternative we identified avoids intact forests entirely while seeking to benefit agriculture and existing settlements. The second alternative also avoids intact forests while incorporating existing paved and unpaved roads to limit construction costs. As currently proposed, the superhighway would be 260 km long, would intersect 115 km of intact forests or protected areas, and would cost an estimated US$2.5 billion to construct. Alternative Routes 1 and 2 are only slightly longer (290 and 353 km, respectively) and have markedly lower estimated construction costs (US$0.92 billion). Furthermore, the alternative routes would have negligible impacts on forests and protected areas and would be better aligned to benefit local communities and agriculture. We argue that alternative routings such as those we examined here could markedly reduce the economic and environmental costs, and potentially increase the socioeconomic benefits, for the proposed Cross River Superhighway.
This study analyzed the spatiotemporal pattern of settlement expansion in Abuja, Nigeria, one of ... more This study analyzed the spatiotemporal pattern of settlement expansion in Abuja, Nigeria, one of West Africa's fastest developing cities, using geoinformation and ancillary datasets. Three epochs of Land-use Land-cover (LULC) maps for 1986, 2001 and 2014 were derived from Landsat images using support vector machines (SVM). Accuracy assessment (AA) of the LULC maps based on the pixel count resulted in overall accuracy of 82%, 92% and 92%, while the AA derived from the error adjusted area (EAA) method stood at 69%, 91% and 91% for 1986, 2001 and 2014, respectively. Two major techniques for detecting changes in the LULC epochs involved the use of binary maps as well as a post-classification comparison approach. Quantitative spatiotemporal analysis was conducted to detect LULC changes with specific focus on the settlement development pattern of Abuja, the federal capital city (FCC) of Nigeria. Logical transitions to the urban category were modelled for predicting future scenarios for the year 2050 using the embedded land change modeler (LCM) in the IDRISI package. Based on the EAA, the result showed that urban areas increased by more than 11% between 1986 and 2001. In contrast, this value rose to 17% between 2001 and 2014. The LCM model projected LULC changes that showed a growing trend in settlement expansion, which might take over allotted spaces for green areas and agricultural land if stringent development policies and enforcement measures are not implemented. In conclusion, integrating geospatial technologies with ancillary datasets offered improved understanding of how urbanization processes such as increased imperviousness of such a magnitude could influence the urban microclimate through the alteration of natural land surface temperature. Urban expansion could also lead to increased surface runoff as well as changes in drainage geography leading to urban floods.
Digital Elevation Models (DEMs) often provides inputs to natural hazard assessment and modeling. ... more Digital Elevation Models (DEMs) often provides inputs to natural hazard assessment and modeling. In the present work different DEM data sources and software’s were compared to generate Digital Terrain Model (DTM) outputs and their plausibility in different stages of natural hazard assessment and analysis. The Alvaro area of Basilicata of Italy was considered suitable for this study due to the terrain and hydrological processes going on in the area. The study required to integrate Remote sensing (RS), GIS techniques to inspect these different DEM sources viz a viz software outputs to assess their plausibility for hazard specific DTM parametizations and derivation. The resolutions of the DEM datasets from providers commonly differ and require critical assessment to determine their quality which might suggest their fitness for use for various natural hazard terrain and hydrodynamic modeling. To experiment on this and produce rational advice for users we used DEMs from SRTM, ASTER-GDEM, and contour derived DEM datasets. Integrated RS and GIS based procedures were implemented on these datasets using ArcGIS Spatial Analyst; ArcHydro in ArcGIS and ILWIS, software’s. The results revealed that DTM derivative differs from software to software which is a function of datasets characteristics. In view of this known premise it is necessary to critically assess DEM dataset with a variety of software before use to guide against false impression on DTM quality and fitness for use in decision making. After using ArcGIS and Ilwis we conclude that DEM hydro-processing modules in Ilwis software produce user controlled DEM derivatives for hydrodynamic modeling than in ArcGIS which is more of a black box processor.
Historical topographic maps are distinct sources of spatial information for hind-cast studies. Th... more Historical topographic maps are distinct sources of spatial information for hind-cast studies. They are acclaimed to be one of the most reliable legacy archives representing and describing geographic features prior to aerial photography and the present day satellite imagery. However, two major challenges are encountered in extracting information from these sources. These challenges are conceptual and technical emanating from scanning artefacts, inherent map complexity and analogousness, although information extraction has been manually done through digitizing, pixel-based methods and visual map analysis, which are time consuming and tedious. Hence, there is urgent need to explore robust and reliable methods such as the object-oriented analysis (OOA) to efficiently develop new information extraction techniques for scanned topographic paper maps. Therefore, this research investigated and answered questions about conceptualization, development, implementation and transferability of an OOA-based information extraction method for complex papers maps and potential applications.
The tropical forests of Central Africa sustain exceptionally high biodiversity and environmental ... more The tropical forests of Central Africa sustain exceptionally high biodiversity and environmental services such as forest hydrology and carbon storage. These forests span the Congo Basin and equatorial forests adjoining it. Like much of sub-Saharan Africa, this region facing dramatic changes in the number, extent, and environmental impacts of large-scale infrastructure projects. A particular concern is how such projects will affect important wildlife habitats, protected areas, and environmental services.