scholarly journals Global urban growth between 1870 and 2100 from integrated high resolution mapped data and urban dynamic modeling

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Xuecao Li ◽  
Yuyu Zhou ◽  
Mohamad Hejazi ◽  
Marshall Wise ◽  
Chris Vernon ◽  
...  

AbstractLong term, global records of urban extent can help evaluate environmental impacts of anthropogenic activities. Remotely sensed observations can provide insights into historical urban dynamics, but only during the satellite era. Here, we develop a 1 km resolution global dataset of annual urban dynamics between 1870 and 2100 using an urban cellular automata model trained on satellite observations of urban extent between 1992 and 2013. Hindcast (1870–1990) and projected (2020–2100) urban dynamics under the five Shared Socioeconomic Pathways (SSPs) were modeled. We find that global urban growth under SSP5, the fossil-fuelled development scenario, was largest with a greater than 40-fold increase in urban extent since 1870. The high resolution dataset captures grid level urban sprawl over 200 years, which can provide insights into the urbanization life cycle of cities and help assess long-term environmental impacts of urbanization and human–environment interactions at a global scale.

Author(s):  
Y.A. Maleeks ◽  
A.O. Aliyu ◽  
A. Bala ◽  
A.U. Isiaka ◽  
K.Z. Atta

The pattern of development in a city is mostly governed by urban dynamics, with population increase being the primary driving force. Built-up cover is the most important predictor of urban expansion. Zuru metropolis in Kebbi State has witnessed remarkable developmental activities caused by human influences such as buildings, road constructions, and population growth for over decades. Urban growth was ascertained for a period of 30 years through the analysis of Landsat imagery of 1988, 1998, 2008 and 2018. The datasets were classified into five (5) land covers, namely, built-up, water body, rocky surface, vegetation, and others. Quantitative assessment of the urban growth was ascertained by computing post-classification LC dynamics and Land Consumption Rate/Land Absorption Coefficient (LCR/LAC). The results showed that the built-up cover (urban area) conspicuously increased with area of 693.35 ha, 728.74 ha, 5210.5 ha and 6845.75 ha respectively for the period of study (1988 – 2018). The increment in built-up area was indicative of population growth from 1988 to 2018. The study revealed that between 1988 to 2018 showed that built-up increased by 11.78%, while rocky surface and water body have shrunk by 16.44% and 0.02% respectively, which can be attributed to anthropogenic activities in which rocky surface and waterbody have been transformed into built-up cover. It further revealed that the urban area experienced crowdedness in the years 2008 and 2018 respectively due to high LCR values of 2.71% compared to LCR values of 0.0714% and 0.0558% in 1988 and 1998. Land transformation into urban area and spread of the population to the outskirts of the study area was prominent between 1998 and 2008 due to high LAC value of 0.0998. The study concluded that there was transformation of rocky surface and waterbody into urban area, which was caused by population growth, human and agricultural activities in Zuru metropolis.


2016 ◽  
Vol 33 (7) ◽  
pp. 1519-1538 ◽  
Author(s):  
Paul W. Staten ◽  
Brian H. Kahn ◽  
Mathias M. Schreier ◽  
Andrew K. Heidinger

AbstractThis paper describes a cloud type radiance record derived from NOAA polar-orbiting weather satellites using cloud properties retrieved from the Advanced Very High Resolution Radiometer (AVHRR) and spectral brightness temperatures (Tb) observed by the High Resolution Infrared Radiation Sounder (HIRS). The authors seek to produce a seamless, global-scale, long-term record of cloud type and Tb statistics intended to better characterize clouds from seasonal to decadal time scales. Herein, the methodology is described in which the cloud type statistics retrieved from AVHRR are interpolated onto each HIRS footprint using two cloud classification methods. This approach is tested over the northeast tropical and subtropical Pacific Ocean region, which contains a wide variety of cloud types during a significant ENSO variation from 2008 to 2009. It is shown that the Tb histograms sorted by cloud type are realistic for all HIRS channels. The magnitude of Tb biases among spatially coincident satellite intersections over the northeast Pacific is a function of cloud type and wavelength. While the sign of the bias can change, the magnitudes are generally small for NOAA-18 and NOAA-19, and NOAA-19 and MetOp-A intersections. The authors further show that the differences between calculated standard deviations of cloud-typed Tb well exceed intersatellite calibration uncertainties. The authors argue that consideration of higher-order statistical moments determined from spectral infrared observations may serve as a useful long-term measure of small-scale spatial changes, in particular cloud types over the HIRS–AVHRR observing record.


Author(s):  
A. D. Chalfoun

Abstract Purpose of Review Anthropogenic activities can lead to the loss, fragmentation, and alteration of wildlife habitats. I reviewed the recent literature (2014–2019) focused on the responses of avian, mammalian, and herpetofaunal species to oil and natural gas development, a widespread and still-expanding land use worldwide. My primary goals were to identify any generalities in species’ responses to development and summarize remaining gaps in knowledge. To do so, I evaluated the directionality of a wide variety of responses in relation to taxon, location, development type, development metric, habitat type, and spatiotemporal aspects. Recent Findings Studies (n = 70) were restricted to the USA and Canada, and taxonomically biased towards birds and mammals. Longer studies, but not those incorporating multiple spatial scales, were more likely to detect significant responses. Negative responses of all types were present in relatively low frequencies across all taxa, locations, development types, and development metrics but were context-dependent. The directionality of responses by the same species often varied across studies or development metrics. Summary The state of knowledge about wildlife responses to oil and natural gas development has developed considerably, though many biases and gaps remain. Studies outside of North America and that focus on herpetofauna are lacking. Tests of mechanistic hypotheses for effects, long-term studies, assessment of response thresholds, and experimental designs that isolate the effects of different stimuli associated with development, remain critical. Moreover, tests of the efficacy of habitat mitigation efforts have been rare. Finally, investigations of the demographic effects of development across the full annual cycle were absent for non-game species and are critical for the estimation of population-level effects.


2021 ◽  
Vol 10 (6) ◽  
pp. 384
Author(s):  
Javier Martínez-López ◽  
Bastian Bertzky ◽  
Simon Willcock ◽  
Marine Robuchon ◽  
María Almagro ◽  
...  

Protected areas (PAs) are a key strategy to reverse global biodiversity declines, but they are under increasing pressure from anthropogenic activities and concomitant effects. Thus, the heterogeneous landscapes within PAs, containing a number of different habitats and ecosystem types, are in various degrees of disturbance. Characterizing habitats and ecosystems within the global protected area network requires large-scale monitoring over long time scales. This study reviews methods for the biophysical characterization of terrestrial PAs at a global scale by means of remote sensing (RS) and provides further recommendations. To this end, we first discuss the importance of taking into account the structural and functional attributes, as well as integrating a broad spectrum of variables, to account for the different ecosystem and habitat types within PAs, considering examples at local and regional scales. We then discuss potential variables, challenges and limitations of existing global environmental stratifications, as well as the biophysical characterization of PAs, and finally offer some recommendations. Computational and interoperability issues are also discussed, as well as the potential of cloud-based platforms linked to earth observations to support large-scale characterization of PAs. Using RS to characterize PAs globally is a crucial approach to help ensure sustainable development, but it requires further work before such studies are able to inform large-scale conservation actions. This study proposes 14 recommendations in order to improve existing initiatives to biophysically characterize PAs at a global scale.


2021 ◽  
Vol 13 (5) ◽  
pp. 949
Author(s):  
Salman Qureshi ◽  
Saman Nadizadeh Shorabeh ◽  
Najmeh Neysani Samany ◽  
Foad Minaei ◽  
Mehdi Homaee ◽  
...  

Due to irregular and uncontrolled expansion of cities in developing countries, currently operational landfill sites cannot be used in the long-term, as people will be living in proximity to these sites and be exposed to unhygienic circumstances. Hence, this study aims at proposing an integrated approach for determining suitable locations for landfills while considering their physical expansion. The proposed approach utilizes the fuzzy analytical hierarchy process (FAHP) to weigh the sets of identified landfill location criteria. Furthermore, the weighted linear combination (WLC) approach was applied for the elicitation of the proper primary locations. Finally, the support vector machine (SVM) and cellular automation-based Markov chain method were used to predict urban growth. To demonstrate the applicability of the developed approach, it was applied to a case study, namely the city of Mashhad in Iran, where suitable sites for landfills were identified considering the urban growth in different geographical directions for this city by 2048. The proposed approach could be of use for policymakers, urban planners, and other decision-makers to minimize uncertainty arising from long-term resource allocation.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Melissa Ong ◽  
Mark Gibson ◽  
Gerald Coakley

Abstract Case report - Introduction Severe acute respiratory coronavirus 2 (SARS-CoV-2) is a novel virus that can lead to an excessive immune activation and cytokine response known as Coronavirus disease 2019 (COVID-19) which predominantly affects the lungs. Patients with chronic inflammatory disease on biological immunosuppressive treatments may be at a higher risk of contracting SARS-CoV-2. However, it is yet to be determined whether immunomodulatory medications used in inflammatory diseases have protective capabilities against severe outcomes. Case report - Case description A 51-year old female with a 13-year history of rheumatoid arthritis (RA) presented to hospital with fever, exertional breathlessness, and a non-productive cough. She was diagnosed with seropositive erosive RA at the age of 38 and was on 6-monthly Rituximab infusions and Leflunomide on admission. She had relatively stable pulmonary fibrosis (diagnosed in 2010). Her chest CTs in 2010 and 2018 noted bilateral basal subpleural ground glass change with limited honeycombing and spirometry study revealed FEV1 of 2.2 (82% predicted), VC of 2.7 (87% predicted), DLCO of 7.0 (78% predicted) and kCO of 1.6 (78% predicted). On admission in March 2020, she was hypoxic (oxygen saturation of 88% in room air) and had raised inflammatory markers (CRP 341mg/dL, d-Dimer 914ng/ml, Ferritin 3141ng/ml, LDH 672U/L). Her last Rituximab infusion was 3 months prior and leflunomide was withheld on admission. SARS-CoV-2 PCR nasopharyngeal swab was positive, and she was recruited to the RECOVERY trial, being randomized to Lopinavir-Ritonavir for 10 days. Her oxygen requirements increased, and a CT pulmonary angiogram excluded pulmonary embolism but revealed ground glass changes and extensive multilobar consolidation. She was eligible for recruitment into RECOVERY-2 (tocilizumab) given the ongoing oxygen requirement and elevated CRP, but she was randomised to usual care. She was commenced on 80mg of IV methylprednisolone, a dose chosen because of its proven effectiveness in Acute Respiratory Distress Syndrome. She clinically improved and was discharged from hospital 20 days after starting Methylprednisolone with a CRP of 17mg/dL. Two months after discharge, the patient had repeat spirometry study which noted FEV1 of 1.4 (57% predicted), VC of 1.5 (52% predicted), DLCO of 2.4 (28% predicted) and kCO of 1.0 (47% predicted). A repeat high-resolution chest CT reported significant improvement of peripheral ground glass changes and consolidation, but she is still fatigued and more breathless than previously. Case report - Discussion The RECOVERY trial concluded that Dexamethasone reduced mortality in intubated patients and in hospitalised patients with COVID-19 with a high oxygen requirement. The results were published after this patient was discharged. A hyperinflammatory response to COVID-19 is seen in a subset of patients, and our own hospital data suggest that this condition affects around 5% of admitted COVID-19 patients, but that extreme hyperferritinaemia above 10,000 is extremely rare. Similar responses (known as Haemophagocytic Lymphohistiocytosis [HLH]) are seen with a variety of viral and bacterial infections, in malignancy and in inflammatory rheumatic diseases (Macrophage Activation Syndrome [MAS]), but typically HLH and MAS patients have ferritin > 10,000. It appears unlikely that true HLH is a significant manifestation of COVID-19 infection, but moderate hyperferritinaemia is not uncommon and the results of this study, taken together with case reports and series from China and Italy suggest that similar treatments to those used in HLH may transform the prognosis for COVID-19 patients in this subset. It is unknown whether the recent Rituximab infusion had a role in reducing the “cytokine storm” and delaying progression to severe COVID-19. However, it may be argued that the remaining T cells in B cell depleted patients are sufficient for viral clearance. The long-term impact of SARS-CoV-2 on pulmonary function is still unclear. Our patient had a major deterioration in her lung function when compared to her baseline. There was severe reduction in gas transfer post COVID-19. However, her repeat high resolution CT chest reported substantial improvement in ground glass changes and consolidation. The long-term prognosis is still uncertain. Initial fears that patients on DMARDs and biological therapies for inflammatory rheumatic disease would be extremely vulnerable to COVID-19 have not been confirmed, but patients with extra-articular manifestations on combinations of DMARDs and biological therapies may be a subset at higher risk. Case report - Key learning points Our Intensivist colleagues, early in the COVID-19 outbreak, were understandably cautious about using heavily immunosuppressive treatments for a life-threatening viral infection. Using a multi-disciplinary approach at a time when knowledge of how to treat this condition was rudimentary, along with informed consent from an intelligent and thoughtful patient, we were able to plot a middle path to suppress hyperinflammation without using massively immunosuppressive doses of steroid, with a successful outcome. This patient illustrates one aspect of the hyper-inflammatory response seen in a subset of the most critically ill patients with COVID-19. At the time of writing, the RECOVERY 2 trial is yet to be published, but the rapid improvement in inflammatory markers including CRP and Ferritin, along with a dramatic improvement in clinical state, suggest that relatively modest doses of parenteral steroid have life-saving potential at far lower cost and greater worldwide availability than biological therapies such as Tocilizumab or Anakinra. Trials of Tocilizumab in RECOVERY2 and of Anakinra coordinated by the Hyperinflammation Histio UK Haemophagocytosis Across Specialty Collaboration (HASC), as well as international randomised controlled trials will be critical in determining the optimal treatment strategy for this subset of critically ill COVID-19 patients. The experience of our patient suggests that one arm of such studies should include a relatively modest dose of parenteral steroid, be that Dexamethasone or Methylprednisolone, particularly given that COVID-19 is affecting countries across the developing, as well as the developed, world.


2021 ◽  
pp. 146801812110191
Author(s):  
William Hynes

New economic thinking and acting through a systemic approach could outline policy alternatives to tackle the global-scale systemic challenges of financial, economic, social and environmental emergencies, and help steer our recovery out of the current crisis. A systemic recovery requires an economic approach that balances several factors - markets and states, efficiency and resilience, growth and sustainability, national and global stability, short-term emergency measures and long-term structural change. To achieve this, we need to think beyond our policy silos, comprehend our interconnections, and build resilience into our systems.


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