1,720,986 research outputs found
Earth observation for quantifying urban growth and its application to sustainable city development
No full textUrban areas are predicted to triple by 2030 in accommodating 68% of the global population, with anthropogenic landscape modifications to impervious surfaces established as a critical driving force in local and global climate change. Accurate temporal monitoring of urban expansion and subsequent environmental issues are essential for ensuring the future sustainability of our cities. In particular the urban heat island effect is considered one of the major problems posed to humans in the 21st century associated with detrimental health impacts and increased energy demand, emissions, water output and economic expenditure. Yet, alongside a uniform modelling omission from global climate models, mitigation of the urban heat island effect lacks a global standardised framework, representative data for modelling impacts, and robust academic outputs for policy incorporation. These limitations are precluding effective data-informed governance. This thesis presents a holistic policy-applicable approach for accurately monitoring and sustainably planning (re)development in relation to metropolitan and local level urban temperature dynamics. This is achieved through generating land cover maps from Earth observation data using a temporally consistent methodology with refinements to urban estimates based upon comparison to high resolution imagery. Variations between changes in land cover and land surface temperature are determined at the metropolitan level to aid sustainable urban growth plans. Temperature is then minimised at the local level through a modelling approach to optimally place vegetation with a proposed new development. The application area for this thesis is the Perth Metropolitan Region in Western Australia which has experienced sustained outward,non-strategic and low density expansion in response to booming natural resource sector. The presented methodology makes progress to aligning urban heat island mitigation efforts with global targets including the United Nation’s Sustainable Development Goals and New Urban Agenda, providing a reproducible method, transferable to other global metropolitan regions to improve sustainable city planning
Environmental livelihood security in Southeast Asia and Oceania
No full textThis policy brief integrates sustainable livelihoods thinking into discussions on environmental security and the water-food-energy nexus, responding both to a gap in the literature and to emerging policy discourse. We present the first conceptualization of ‘environmental livelihood security’, a concept which draws upon frameworks of water-energy-food security and sustainable livelihoods. The geographical focus is Southeast Asia and Oceania, a region where populations are particularly vulnerable and threatened by the impacts of a changing climate. Various socio-environmental pressures act as an external forcing mechanism on communities attaining environmental livelihood security in this region. We provide a primer for using geospatial information to enable the development of a framework to spatially assess environmental livelihood security. The value of this research is highlighted through linkages to ongoing sustainable development and climate-compatible discussions, and by identifying the relevance for influencing policy agendas
An assessment of earthquake vulnerabilities in Kathmandu, Nepal for identification of optimal immediate aid sites
No full textPre-event vulnerability assessments are an emerging discipline within earthquake risk studies. However, owing to extensive data collection for appropriate building stock representation and associated vulnerability, the majority of studies fail to comprehend the multifaceted nature of building vulnerability for pre-event assessments. Furthermore, few studies explore optimal immediate aid sites for the distribution of aid materials in a post-event scenario. New and novel tools recently released by the Global Earthquake Model (GEM) are implemented to overcome limitations of previous studies, permitting standardised repeatable Worldwide results, fulfilling the call from the Organisation for Economic Cooperation and Development (OCED) for the establishment of open source risk assessment tools
Urbanisation-induced land cover temperature dynamics for sustainable future urban heat island mitigation
No full textUrban land cover is one of the fastest global growing land cover types which permanently alters land surface properties and atmospheric interactions, often initiating an urban heat island effect. Urbanisation comprises a number of land cover changes within metropolitan regions. However, these complexities have been somewhat neglected in temperature analysis studies of the urban heat island effect, whereby over-simplification ignores the heterogeneity of urban surfaces and associated land surface temperature dynamics. Accurate spatial information pertaining to these land cover change – temperature relationships across space is essential for policy integration regarding future sustainable city planning to mitigate urban heat impacts. Through a multi-sensor approach, this research disentangles the complex spatial heterogeneous variations between changes in land cover (Landsat data) and land surface temperature (MODIS data), to understand the urban heat island effect dynamics in greater detail for appropriate policy integration. The application area is the rapidly expanding Perth Metropolitan Region (PMR) in Western Australia (WA). Results indicate that land cover change from forest to urban is associated with the greatest annual daytime and nighttime temperature change of 0.40 °C and 0.88 °C respectively. Conversely, change from grassland to urban minimises temperature change at 0.16 °C and 0.77 °C for annual daytime and nighttime temperature respectively. These findings are important to consider for proposed developments of the city as such detail is not currently considered in the urban growth plans for the PMR. The novel intra-urban research approach presented can be applied to other global metropolitan regions to facilitate future transition towards sustainable cities, whereby urban heat impacts can be better managed through optimised land use planning, moving cities towards alignment with the 2030 sustainable development goals and the City Resilience Framework (CRF)
Classified earth observation data between 1990 and 2015 for the Perth Metropolitan Region, Western Australia using the Import Vector Machine algorithm
No full textThis dataset represents land cover for 7 sequential snapshots (1990, 2000, 2003, 2005, 2007, 2013 and 2015) over the Perth Metropolitan Region, Western Australia (WA) derived from medium resolution Landsat data. Cloud free imagery was acquired in or close to the month of July coinciding with WA's winter months coinciding with peak green-up facilitating the greatest contrast between spectrally similar surfaces (e.g. bare earth and urban). Imagery was first standardised and normalised to remove inherent residual noise (e.g. differences in modelled atmospheric correction parameters) whilst permitting classification of all imagery based upon a single classification model. The model was computed from the 2005 image representing the month post maximum rainfall of all considered imagery associated with peak greenness and maximum spectral separability. Classification of the normalised data was achieved with the Import Vector Machine (IVM) algorithm following a hybrid forward/backward strategy that adds import vectors whilst continuously testing validity in each step, producing a sparse and more accurate classification solution. Classified land cover data is provided in raster format (.tif) and divided into the classes: bare earth (1), grassland (2), low urban albedo (e.g. asphalt (3)), water (4), forest (5) and high urban albedo (e.g. concrete (6)). Please see MacLachlan et al. (2017) for further details.
Supplement to: MacLachlan, A.; Biggs, E.; Roberts, G.; Boruff, B. Urban Growth Dynamics in Perth, Western Australia: Using Applied Remote Sensing for Sustainable Future Planning. Land 2017, 6, 9. doi:10.3390/land6010009
Also available at the pangea data publisher for earth and environmental science. doi: doi.pangaea.de/10.1594/PANGAEA.871017</span
Sustainable City Planning: A Data-Driven Approach for Mitigating Urban Heat
Full text linkUrban areas are expected to triple by 2030 in order to accommodate 60% of the global population. Anthropogenic landscape modifications expand coverage of impervious surfaces inducing the urban heat island (UHI) effect, a critical twenty first century challenge associated with increased economic expenditure, energy consumption, and adverse health impacts. Yet, omission of UHI measures from global climate models and metropolitan planning methodologies precludes effective sustainable development governance. We present an approach that integrates Earth observation and climate data with three-dimensional urban models to determine optimal tree placement (per square meter) within proposed urban developments to enable more effective localized UHI mitigation. Such data-driven planning decisions will enhance the future sustainability of our cities to align with current global urban development agendas
Sub-pixel land cover classification for improved urban area estimates using Landsat
Full text linkUrban areas are Earth’s fastest growing land use that impact hydrological and ecological systems and the surface energy balance. The identification and extraction of accurate spatial information relating to urban areas is essential for future sustainable city planning owing to its importance within global environmental change and human-environment interactions. However, monitoring urban expansion using medium resolution (30-250m) imagery remains challenging due to the variety of surface materials that contribute to measured reflectance resulting in spectrally mixed pixels. This research integrates high spatial resolution orthophotos and Landsat imagery to identify differences across a range of diverse urban subsets within the rapidly expanding Perth Metropolitan Region, Western Australia. Results indicate that calibrating Landsat derived sub-pixel land cover estimates with correction values (calculated from spatially explicit comparisons of sub-pixel Landsat values to classified high resolution data which accounts for over (under) estimations of Landsat) reduces moderate resolution urban area over (under) estimates by on average 55.08% for the Perth Metropolitan Region. This approach can be applied to other urban areas globally through use of frequently available and/or low cost high spatial resolution imagery (e.g. using Google Earth). This will improve urban growth estimations to help monitor and measure change whilst providing metrics to facilitate sustainable urban development targets within cities around the world
Urban growth dynamics in Perth, Western Australia: using applied remote sensing for sustainable future planning
Full text linkEarth observation data can provide valuable assessments for monitoring the spatial extent of (un)sustainable urban growth of the world’s cities to better inform planning policy in reducing associated economic, social and environmental costs. Western Australia has witnessed rapid economic expansion since the turn of the century founded upon extensive natural resource extraction. Thus, Perth, the state capital of Western Australia, has encountered significant population and urban growth in response to the booming state economy. However, the recent economic slowdown resulted in the largest decrease in natural resource values that Western Australia has ever experienced. Here, we present multi-temporal urban expansion statistics from 1990 to 2015 for Perth, derived from Landsat imagery. Current urban estimates used for future development plans and progress monitoring of infill and density targets are based upon aggregated census data and metrics unrepresentative of actual land cover change, underestimating overall urban area. Earth observation provides a temporally consistent methodology, identifying areal urban area at higher spatial and temporal resolution than current estimates. Our results indicate that the spatial extent of the Perth Metropolitan Region has increased 45% between 1990 and 2015, over 320 km2. We highlight the applicability of earth observation data in accurately quantifying urban area for sustainable targeted planning practices
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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