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Articles 61 - 90 of 232
Full-Text Articles in Geography
Impacts Of Covid-19 On Us Agri-Food Supply Chain Businesses: Regional Survey Results, Hikaru Hanawa Peterson, Gigi Digiacomo, Christa D. Court, Michelle Miller, Gustavo Oliveira, Andrew W. Stevens, Li Zhang, Lauri M. Baker, Joseph Nowak, Eyrika Orlando, Bijeta Bijen Saha
Impacts Of Covid-19 On Us Agri-Food Supply Chain Businesses: Regional Survey Results, Hikaru Hanawa Peterson, Gigi Digiacomo, Christa D. Court, Michelle Miller, Gustavo Oliveira, Andrew W. Stevens, Li Zhang, Lauri M. Baker, Joseph Nowak, Eyrika Orlando, Bijeta Bijen Saha
Geography
Visible disruptions of appropriate food distribution for end consumers during the onset of the COVID-19 pandemic prompted calls for an urgent, renewed look at how the U.S. agri-food system is impacted by and responds to pandemics, natural disasters, and human-made crises. Previous studies suggest the COVID-19 pandemic yielded uneven impacts across agri-food supply chain segments and regions. For a rigorously comparable assessment of the impact of COVID-19 on agri-food businesses, a survey was administered from February to April 2021 to five segments of the agri-food supply chain in three study regions (California, Florida, and the two-state region of Minnesota-Wisconsin). Results …
Itsdm: Isolation Forest-Based Presence-Only Species Distribution Modelling And Explanation In R, Lei Song, Lyndon Estes
Itsdm: Isolation Forest-Based Presence-Only Species Distribution Modelling And Explanation In R, Lei Song, Lyndon Estes
Geography
Multiple statistical algorithms have been used for species distribution modelling (SDM). Due to shortcomings in species occurrence datasets, presence-only methods (such as MaxEnt) have become increasingly widely used. However, sampling bias remains a challenging issue, particularly for density-based approaches. The Isolation Forest (iForest) algorithm is a presence-only method less sensitive to sampling patterns and over-fitting because it fits the model by describing the unsuitable instead of suitable conditions. Here, we present the itsdm package for species distribution modelling with iForest, which provides a workflow wrapper for the algorithms in iForest family and convenient tools for model diagnostic and post-modelling analysis. …
Situational Analysis And Urban Theory, Mark Davidson
Situational Analysis And Urban Theory, Mark Davidson
Geography
Urban geographers have been pursuing divergent theoretical projects. Some have pushed urban theory to become ageographical, the goal being to search out and explain of a globally omnipotent urbanization process. Others have moved in a different direction, seeking to detail how singular constellations of processes produce only particular urban places. This theoretical divergence has led some to question whether middle-range urban theories continue to have purchase today. This paper seeks to contribute to this attempt to rekindle an interest in middle-range urban theory by examining the relevance of Karl Popper’s situational analysis to how we understand contemporary urbanization. © The …
Adaptation Rationales And Benefits: A Foundation For Understanding Adaptation Impact, Edward R. Carr, Johanna Nalau
Adaptation Rationales And Benefits: A Foundation For Understanding Adaptation Impact, Edward R. Carr, Johanna Nalau
Geography
Efforts to achieve coordinated, effective, and impactful adaptation outcomes are complicated by factors ranging from the local specificity of adaptation needs to the challenges of politics and prioritization that drive funding decisions. However, these and other challenges are perpetuated and exacerbated by poorly constructed, often implicit, and generally institution- or context-specific impact pathways connecting policy/institutional priorities through their materialization in specific actions to their intended outcomes. We call these impact pathways adaptation rationales, as they represent the logic of an adaptation action. The implicit nature of most current adaptation rationales makes it difficult to identify and test the accuracy and …
A Comprehensive Satellite-Based Assessment Across The Pacific Arctic Distributed Biological Observatory Shows Widespread Late-Season Sea Surface Warming And Sea Ice Declines With Significant Influences On Primary Productivity, Karen E. Frey, Josefino C. Comiso, Larry V. Stock, Luisa N C Young, Lee W. Cooper, Jacqueline M. Grebmeier
A Comprehensive Satellite-Based Assessment Across The Pacific Arctic Distributed Biological Observatory Shows Widespread Late-Season Sea Surface Warming And Sea Ice Declines With Significant Influences On Primary Productivity, Karen E. Frey, Josefino C. Comiso, Larry V. Stock, Luisa N C Young, Lee W. Cooper, Jacqueline M. Grebmeier
Geography
Massive declines in sea ice cover and widespread warming seawaters across the Pacific Arctic region over the past several decades have resulted in profound shifts in marine ecosystems that have cascaded throughout all trophic levels. The Distributed Biological Observatory (DBO) provides sampling infrastructure for a latitudinal gradient of biological "hotspot" regions across the Pacific Arctic region, with eight sites spanning the northern Bering, Chukchi, and Beaufort Seas. The purpose of this study is two-fold: (a) to provide an assessment of satellite-based environmental variables for the eight DBO sites (including sea surface temperature (SST), sea ice concentration, annual sea ice persistence …
Four Fundamental Questions To Evaluate Land Change Models With An Illustration Of A Cellular Automata–Markov Model, Cláudia M. Viana, Robert Gilmore Pontius, Jorge Rocha
Four Fundamental Questions To Evaluate Land Change Models With An Illustration Of A Cellular Automata–Markov Model, Cláudia M. Viana, Robert Gilmore Pontius, Jorge Rocha
Geography
Numerous models exist for users to simulate land change to communicate with an audience concerning future land change. This article raises four fundamental questions to help model users decide whether to use any model: (1) Can the user understand the model? (2) Can the audience understand the model? (3) Can the user control the model? (4) Does the model address the goals of the specific application? This article applies these questions to the popular cellular automata–Markov (CA–Markov) model as IDRISI’s CA–Markov module expresses. Sensitivity analysis examines 120 ways to set the module’s parameters. Verification compares the module’s behavior to the …
Ten New Insights In Climate Science 2023/2024, Mercedes Bustamante, Joyashree Roy, Daniel Ospina, Ploy Achakulwisut, Anubha Aggarwal, Ana Bastos, Wendy Broadgate, Josep G. Canadell, Edward Carr, Deliang Chen, Helen A. Cleugh, Kristie L. Ebi
Ten New Insights In Climate Science 2023/2024, Mercedes Bustamante, Joyashree Roy, Daniel Ospina, Ploy Achakulwisut, Anubha Aggarwal, Ana Bastos, Wendy Broadgate, Josep G. Canadell, Edward Carr, Deliang Chen, Helen A. Cleugh, Kristie L. Ebi
Geography
Non-technical summary: We identify a set of essential recent advances in climate change research with high policy relevance, across natural and social sciences: (1) looming inevitability and implications of overshooting the 1.5°C warming limit, (2) urgent need for a rapid and managed fossil fuel phase-out, (3) challenges for scaling carbon dioxide removal, (4) uncertainties regarding the future contribution of natural carbon sinks, (5) intertwinedness of the crises of biodiversity loss and climate change, (6) compound events, (7) mountain glacier loss, (8) human immobility in the face of climate risks, (9) adaptation justice, and (10) just transitions in food systems. Technical …
A Century Of Drought In HawaiʻI: Geospatial Analysis And Synthesis Across Hydrological, Ecological, And Socioeconomic Scales, Abby G. Frazier, Christian P. Giardina, Thomas W. Giambelluca, Laura Brewington, Yi Leng Chen, Pao Shin Chu, Lucas Berio Fortini, Danielle Hall, David A. Helweg, Victoria W. Keener, Ryan J. Longman, Matthew P. Lucas, Alan Mair, Delwyn S. Oki, Julian J. Reyes, Stephanie G. Yelenik, Clay Trauernicht
A Century Of Drought In HawaiʻI: Geospatial Analysis And Synthesis Across Hydrological, Ecological, And Socioeconomic Scales, Abby G. Frazier, Christian P. Giardina, Thomas W. Giambelluca, Laura Brewington, Yi Leng Chen, Pao Shin Chu, Lucas Berio Fortini, Danielle Hall, David A. Helweg, Victoria W. Keener, Ryan J. Longman, Matthew P. Lucas, Alan Mair, Delwyn S. Oki, Julian J. Reyes, Stephanie G. Yelenik, Clay Trauernicht
Geography
Drought is a prominent feature of Hawaiʻi’s climate. However, it has been over 30 years since the last comprehensive meteorological drought analysis, and recent drying trends have emphasized the need to better understand drought dynamics and multi-sector effects in Hawaiʻi. Here, we provide a comprehensive synthesis of past drought effects in Hawaiʻi that we integrate with geospatial analysis of drought characteristics using a newly developed 100-year (1920–2019) gridded Standardized Precipitation Index (SPI) dataset. The synthesis examines past droughts classified into five categories: Meteorological, agricultural, hydrological, ecological, and socioeconomic drought. Results show that drought duration and magnitude have increased significantly, consistent …
Optimizing Automated Kriging To Improve Spatial Interpolation Of Monthly Rainfall Over Complex Terrain, Matthew P. Lucas, Ryan J. Longman, Thomas W. Giambelluca, Abby G. Frazier, Jared Mclean, Sean B. Cleveland, Yu Fen Huang, Jonghyun Lee
Optimizing Automated Kriging To Improve Spatial Interpolation Of Monthly Rainfall Over Complex Terrain, Matthew P. Lucas, Ryan J. Longman, Thomas W. Giambelluca, Abby G. Frazier, Jared Mclean, Sean B. Cleveland, Yu Fen Huang, Jonghyun Lee
Geography
Gridded monthly rainfall estimates can be used for a number of research applications, including hydrologic modeling and weather forecasting. Automated interpolation algorithms, such as the "autoKrige" function in R, can produce gridded rainfall estimates that validate well but produce unrealistic spatial patterns. In this work, an optimized geostatistical kriging approach is used to interpolate relative rainfall anomalies, which are then combined with long-term means to develop the gridded estimates. The optimization consists of the following: 1) determining the most appropriate offset (constant) to use when log-transforming data; 2) eliminating poor quality data prior to interpolation; 3) detecting erroneous maps using …
High Resolution, Annual Maps Of Field Boundaries For Smallholder-Dominated Croplands At National Scales, Lyndon D. Estes, Su Ye, Lei Song, Boka Luo, J. Ronald Eastman, Zhenhua Meng, Qi Zhang, Dennis Mcritchie, Stephanie R. Debats, Justus Muhando, Angeline H. Amukoa, Brian W. Kaloo, Jackson Makuru, Ben K. Mbatia, Isaac M. Muasa, Julius Mucha, Adelide M. Mugami, Judith M. Mugami, Francis W. Muinde, Fredrick M. Mwawaza, Jeff Ochieng, Charles J. Oduol, Purent Oduor, Thuo Wanjiku, Joseph G. Wanyoike, Ryan B. Avery, Kelly K. Caylor
High Resolution, Annual Maps Of Field Boundaries For Smallholder-Dominated Croplands At National Scales, Lyndon D. Estes, Su Ye, Lei Song, Boka Luo, J. Ronald Eastman, Zhenhua Meng, Qi Zhang, Dennis Mcritchie, Stephanie R. Debats, Justus Muhando, Angeline H. Amukoa, Brian W. Kaloo, Jackson Makuru, Ben K. Mbatia, Isaac M. Muasa, Julius Mucha, Adelide M. Mugami, Judith M. Mugami, Francis W. Muinde, Fredrick M. Mwawaza, Jeff Ochieng, Charles J. Oduol, Purent Oduor, Thuo Wanjiku, Joseph G. Wanyoike, Ryan B. Avery, Kelly K. Caylor
Geography
Mapping the characteristics of Africa’s smallholder-dominated croplands, including the sizes and numbers of fields, can provide critical insights into food security and a range of other socioeconomic and environmental concerns. However, accurately mapping these systems is difficult because there is 1) a spatial and temporal mismatch between satellite sensors and smallholder fields, and 2) a lack of high-quality labels needed to train and assess machine learning classifiers. We developed an approach designed to address these two problems, and used it to map Ghana’s croplands. To overcome the spatio-temporal mismatch, we converted daily, high resolution imagery into two cloud-free composites (the …
Ten Facts About Land Systems For Sustainability, Patrick Meyfroidt, Ariane De Bremond, Casey M. Ryan, Emma Archer, Richard Aspinall, Abha Chhabra, Gilberto Camara, Rinku Roy Chowdhury, Esteve Corbera, Ruth Defries, Sandra Díaz, Jinwei Dong, Erle C. Ellis, Karl Heinz Erb, Janet A. Fisher, Rachael D. Garrett, Nancy E. Golubiewski, H. Ricardo Grau, J. Morgan Grove, Helmut Haberl, Andreas Heinimann, Patrick Hostert, Esteban G. Jobbágy, Suzi Kerr, Tobias Kuemmerle, Eric F. Lambin, Sandra Lavorel, Sharachandra Lele, Ole Mertz, Peter Messerli, Graciela Metternicht, Darla K. Munroe, Harini Nagendra
Ten Facts About Land Systems For Sustainability, Patrick Meyfroidt, Ariane De Bremond, Casey M. Ryan, Emma Archer, Richard Aspinall, Abha Chhabra, Gilberto Camara, Rinku Roy Chowdhury, Esteve Corbera, Ruth Defries, Sandra Díaz, Jinwei Dong, Erle C. Ellis, Karl Heinz Erb, Janet A. Fisher, Rachael D. Garrett, Nancy E. Golubiewski, H. Ricardo Grau, J. Morgan Grove, Helmut Haberl, Andreas Heinimann, Patrick Hostert, Esteban G. Jobbágy, Suzi Kerr, Tobias Kuemmerle, Eric F. Lambin, Sandra Lavorel, Sharachandra Lele, Ole Mertz, Peter Messerli, Graciela Metternicht, Darla K. Munroe, Harini Nagendra
Geography
Land use is central to addressing sustainability issues, including biodiversity conservation, climate change, food security, poverty alleviation, and sustainable energy. In this paper, we synthesize knowledge accumulated in land system science, the integrated study of terrestrial social-ecological systems, into 10 hard truths that have strong, general, empirical support. These facts help to explain the challenges of achieving sustainability in land use and thus also point toward solutions. The 10 facts are as follows: 1) Meanings and values of land are socially constructed and contested; 2) land systems exhibit complex behaviors with abrupt, hard-to-predict changes; 3) irreversible changes and path dependence …
A Process-Model Perspective On Recent Changes In The Carbon Cycle Of North America, Guillermo Murray-Tortarolo, Benjamin Poulter, Rodrigo Vargas, Daniel Hayes, Anna M. Michalak, Christopher A. Williams, Lisamarie Windham-Myers, Jonathan A. Wang, Kimberly P. Wickland, David Butman, Hanqin Tian, Stephen Sitch, Pierre Friedlingstein, Mike O’Sullivan, Peter Briggs, Vivek Arora, Danica Lombardozzi, Atul K. Jain, Wenping Yuan, Roland Séférian, Julia Nabel, Andy Wiltshire, Almut Arneth, Sebastian Lienert, Sönke Zaehle, Vladislav Bastrikov, Daniel Goll, Nicolas Vuichard, Anthony Walker, Etsushi Kato, Xu Yue, Zhen Zhang
A Process-Model Perspective On Recent Changes In The Carbon Cycle Of North America, Guillermo Murray-Tortarolo, Benjamin Poulter, Rodrigo Vargas, Daniel Hayes, Anna M. Michalak, Christopher A. Williams, Lisamarie Windham-Myers, Jonathan A. Wang, Kimberly P. Wickland, David Butman, Hanqin Tian, Stephen Sitch, Pierre Friedlingstein, Mike O’Sullivan, Peter Briggs, Vivek Arora, Danica Lombardozzi, Atul K. Jain, Wenping Yuan, Roland Séférian, Julia Nabel, Andy Wiltshire, Almut Arneth, Sebastian Lienert, Sönke Zaehle, Vladislav Bastrikov, Daniel Goll, Nicolas Vuichard, Anthony Walker, Etsushi Kato, Xu Yue, Zhen Zhang
Geography
Continental North America has been found to be a carbon (C) sink over recent decades by multiple studies employing a variety of estimation approaches. However, several key questions and uncertainties remain with these assessments. Here we used results from an ensemble of 19 state-of-the-art dynamic global vegetation models from the TRENDYv9 project to improve these estimates and study the drivers of its interannual variability. Our results show that North America has been a C sink with a magnitude of 0.37 ± 0.38 (mean and one standard deviation) PgC year−1 for the period 2000–2019 (0.31 and 0.44 PgC year−1 in each …
Chinese Neoglobalization In East Africa: Logics, Couplings And Impacts, Pádraig R. Carmody, James T. Murphy
Chinese Neoglobalization In East Africa: Logics, Couplings And Impacts, Pádraig R. Carmody, James T. Murphy
Geography
The most significant case of transnational state capitalism today is China's Belt and Road Initiative (BRI) which seeks to expand/extend the country's geoeconomic and geopolitical integrations globally. We conceptualise the BRI as manifest principally through industrial offshoring, infrastructure investments and exports from China. These vectors articulate with particular places, forming transnational couplings that shape development outcomes. We examine the BRI's couplings and their development implications in the East African countries of Djibouti, Ethiopia and Kenya where China has engaged significantly. We demonstrate the contingent manner of BRI's variegations; its pragmatism, flexibility, and limitations as a hegemonic or developmental project.
Linking Tree Cover Change To Historical Management Practices In Urban Parks, Sabine Nix, Lara A. Roman, Marc Healy, John Rogan, Hamil Pearsall
Linking Tree Cover Change To Historical Management Practices In Urban Parks, Sabine Nix, Lara A. Roman, Marc Healy, John Rogan, Hamil Pearsall
Geography
Context: Urban tree canopy (UTC) in parks is shaped by complex interactions between social and ecological processes over decades. To understand UTC change in parks, it is critical to identify and characterize the unique set of social processes that drive long-term change. Objectives: We sought to uncover the feedbacks between social processes and long-term UTC changes in parks of a post-industrial city that experienced substantial population loss and park disinvestment. Methods: Our mixed-methods approach involved quantifying spatiotemporal UTC changes and connecting those changes to historical management practices for three parks in Philadelphia, PA (US). We delineated UTC using aerial imagery …
What Makes Wildfires Destructive In California?, Alexandra D. Syphard, Jon E. Keeley, Mike Gough, Mitchell Lazarz, John Rogan
What Makes Wildfires Destructive In California?, Alexandra D. Syphard, Jon E. Keeley, Mike Gough, Mitchell Lazarz, John Rogan
Geography
As human impacts from wildfires mount, there is a pressing need to understand why structures are lost in destructive fires. Despite growing research on factors contributing to structure loss, fewer studies have focused on why some fires are destructive and others are not. We characterized overall differences between fires that resulted in structure loss (“destructive fires”) and those that did not (“non-destructive wildfires”) across three California regions. Then, we performed statistical analyses on large fires only (≥100 ha) to distinguish the primary differences between large destructive large fires and large non-destructive fires. Overall, destructive fires were at least an order …
Applying Landscape Fragmentation Analysis To Icescape Environments: Potential Impacts For The Pacific Walrus (Odobenus Rosmarus Divergens), Anthony Himmelberger, K E. Frey, Florencia Sangermano
Applying Landscape Fragmentation Analysis To Icescape Environments: Potential Impacts For The Pacific Walrus (Odobenus Rosmarus Divergens), Anthony Himmelberger, K E. Frey, Florencia Sangermano
Geography
Sea-ice cover across the Arctic has declined rapidly over the past several decades owing to amplified climate warming. The Pacific walrus (Odobenus rosmarus divergens) relies on sea-ice floes in the St. Lawrence Island (SLI) and Wainwright regions of the Bering and Chukchi seas surrounding Alaska as a platform for rest, feeding and reproduction. Lower concentrations of thick ice floes are generally associated with earlier seasonal fragmentation and shorter annual persistence of sea-ice cover, potentially affecting the life history of the Pacific walrus. In this study, 24 Landsat satellite images were classified into thick ice, thin ice or open water to …
Probabilistic Tracking Of Annual Cropland Changes Over Large, Complex Agricultural Landscapes Using Google Earth Engine, Sitian Xiong, Priscilla Baltezar, Morgan A. Crowley, Michael Cecil, Stefano C. Crema, Eli Baldwin, Jeffrey A. Cardille, Lyndon Estes
Probabilistic Tracking Of Annual Cropland Changes Over Large, Complex Agricultural Landscapes Using Google Earth Engine, Sitian Xiong, Priscilla Baltezar, Morgan A. Crowley, Michael Cecil, Stefano C. Crema, Eli Baldwin, Jeffrey A. Cardille, Lyndon Estes
Geography
Cropland expansion is expected to increase across sub-Saharan African (SSA) countries in the next thirty years to meet growing food needs across the continent. These land transformations will have cascading social and ecological impacts that can be monitored using novel Earth observation techniques that produce datasets complementary to national cropland surveys. In this study, we present a flexible Bayesian data synthesis workflow on Google Earth Engine (GEE) that can be used to fuse optical and synthetic aperture radar data and demonstrate its ability to track agricultural change at national scales. We adapted the previously developed Bayesian Updating of Land Cover …
New Political Ecologies Of Renewable Energy, Sarah Knuth, Ingrid Behrsin, Anthony Levenda, James Mccarthy
New Political Ecologies Of Renewable Energy, Sarah Knuth, Ingrid Behrsin, Anthony Levenda, James Mccarthy
Geography
The critique of fossil fuel regimes has been a foundational concern for the field of political ecology, in its drives to expose the injustices and harms of energy extractivism and its early warnings of the climate crisis. However, it is increasingly evident that renewable energy sources and their infrastructures will carry their own costs and trade-offs, and that critique, resistance and alternative movement-building are needed to forge a truly just renewable energy transition. This theme issue underlines the many ways in which political ecology is well-positioned to lead critical and engaged scholarship in support of energy/climate justice. In this introduction …
Emerging Hot Spot Analysis To Indicate Forest Conservation Priorities And Efficacy On Regional To Continental Scales: A Study Of Forest Change In Selva Maya 2000-2020, Nicholas Cuba, Laura A. Sauls, Anthony J. Bebbington, Denise Humphreys Bebbington, Avecita Chicchon, Pilar Delpino Marimón, Oscar Diaz, Susanna Hecht, Susan Kandel, Tracey Osborne, Rebecca Ray, Madelyn Rivera, John Rogan, Viviana Zalles
Emerging Hot Spot Analysis To Indicate Forest Conservation Priorities And Efficacy On Regional To Continental Scales: A Study Of Forest Change In Selva Maya 2000-2020, Nicholas Cuba, Laura A. Sauls, Anthony J. Bebbington, Denise Humphreys Bebbington, Avecita Chicchon, Pilar Delpino Marimón, Oscar Diaz, Susanna Hecht, Susan Kandel, Tracey Osborne, Rebecca Ray, Madelyn Rivera, John Rogan, Viviana Zalles
Geography
Despite the importance of preserving contiguous tropical forest areas to maintain biodiversity and terrestrial carbon stocks, methodological challenges continue to hinder broad-scale analysis of threats to these forests. Emerging Hot Spot Analysis (EHSA) is a spatial-statistical method that conveys complex information about the temporal dynamics of deforestation across a range of moderate to coarse spatial scales. Using Global Forest Change (GFC) data as inputs, EHSA produces spatially comprehensive, gridded outputs that represent a standardized, reproduceable way to instantiate contiguous forest tracts as spatial objects. Doing so allows aggregation of other GFC-derived values and analysis of alternative geographic configurations besides sub-national …
Albedo Changes Caused By Future Urbanization Contribute To Global Warming, Zutao Ouyang, Pietro Sciusco, Tong Jiao, Sarah Feron, Cheyenne Lei, Fei Li, Ranjeet John, Peilei Fan, Xia Li, Christopher A. Williams, Guangzhao Chen, Chenghao Wang, Jiquan Chen
Albedo Changes Caused By Future Urbanization Contribute To Global Warming, Zutao Ouyang, Pietro Sciusco, Tong Jiao, Sarah Feron, Cheyenne Lei, Fei Li, Ranjeet John, Peilei Fan, Xia Li, Christopher A. Williams, Guangzhao Chen, Chenghao Wang, Jiquan Chen
Geography
The replacement of natural lands with urban structures has multiple environmental consequences, yet little is known about the magnitude and extent of albedo-induced warming contributions from urbanization at the global scale in the past and future. Here, we apply an empirical approach to quantify the climate effects of past urbanization and future urbanization projected under different shared socioeconomic pathways (SSPs). We find an albedo-induced warming effect of urbanization for both the past and the projected futures under three illustrative scenarios. The albedo decease from urbanization in 2018 relative to 2001 has yielded a 100-year average annual global warming of 0.00014 …
A Modified Vegetation Photosynthesis And Respiration Model (Vprm) For The Eastern Usa And Canada, Evaluated With Comparison To Atmospheric Observations And Other Biospheric Models, Sharon M. Gourdji, Anna Karion, Israel Lopez-Coto, Subhomoy Ghosh, Kimberly L. Mueller, Yu Zhou, Christopher A. Williams, Ian T. Baker, Katharine D. Haynes, James R. Whetstone
A Modified Vegetation Photosynthesis And Respiration Model (Vprm) For The Eastern Usa And Canada, Evaluated With Comparison To Atmospheric Observations And Other Biospheric Models, Sharon M. Gourdji, Anna Karion, Israel Lopez-Coto, Subhomoy Ghosh, Kimberly L. Mueller, Yu Zhou, Christopher A. Williams, Ian T. Baker, Katharine D. Haynes, James R. Whetstone
Geography
Atmospheric CO2 measurements from a dense surface network can help to evaluate terrestrial biosphere model (TBM) simulations of Net Ecosystem Exchange (NEE) with two key benefits. First, gridded CO2 flux estimates can be evaluated over regional scales, not possible using flux tower observations at discrete locations for model evaluation. Second, TBM ability to explain atmospheric CO2 fluctuations due to the biosphere can be directly tested, an important objective for anthropogenic emissions monitoring using atmospheric observations. Here, we customize the Vegetation Photosynthesis and Respiration Model (VPRM) for an eastern North American domain with strong biological activity upwind of urban areas. Parameters …
Modeling The Spatial Distribution Of The Current And Future Ecosystem Services Of Urban Tree Planting In Chicopee And Fall River, Massachusetts, R. Moody, N. Geron, M. Healy, J. Rogan, Deborah Martin
Modeling The Spatial Distribution Of The Current And Future Ecosystem Services Of Urban Tree Planting In Chicopee And Fall River, Massachusetts, R. Moody, N. Geron, M. Healy, J. Rogan, Deborah Martin
Geography
Mature urban tree canopy cover disrupts the local effects of urban heat islands and provides important ecosystem services such as energy savings through evaporation and shading, pollution removal, storm runoff control, and carbon sequestration. Sustainable urban tree canopy relies on the planting of juvenile trees. Typically, tree planting programs are only evaluated by the number of trees planted and there is a lack of analysis of juvenile trees post-planting. This study examines the value and distribution of energy savings provided by juvenile trees and how that value changes considering predicted tree growth and mortality by 2050. Using i-Tree Eco software, …
Ownership Is A Habit Of Mind: How Community Land Trusts Expose Key Consensual Fictions Of Urban Property, Deborah Martin
Ownership Is A Habit Of Mind: How Community Land Trusts Expose Key Consensual Fictions Of Urban Property, Deborah Martin
Geography
Community land trusts (“CLTs”) have garnered attention as a novel,
non-state organizational mechanism for enabling permanently
affordable homeownership. In canonical form, they separate
a home from the land upon which it sits, holding the land in trust
and selling the home for its value without the land. Additionally,
CLTs use ground lease restrictions to constrain the resale process
and enforce long-term reproduction of affordability. Herein, we
argue that given the “actually existing” character of CLT practices,
the legal vocabulary CLTs use is not most directly nor most accu-
rately descriptive. The nature of the present intervention is empha-
tically not …
Beyond Biomass To Carbon Fluxes: Application And Evaluation Of A Comprehensive Forest Carbon Monitoring System, Yu Zhou, Christopher A. Williams, Natalia Hasler, Huan Gu, Robert Kennedy
Beyond Biomass To Carbon Fluxes: Application And Evaluation Of A Comprehensive Forest Carbon Monitoring System, Yu Zhou, Christopher A. Williams, Natalia Hasler, Huan Gu, Robert Kennedy
Geography
Accurate quantification of forest carbon stocks and fluxes over regions is needed to monitor forest resources as they respond to changes in climate, disturbance and management, and also to evaluate contributions of forest sector to the regional and global carbon balances. In previous work we introduced a national forest carbon monitoring system (NFCMS) that combines forest inventory data, satellite remote sensing of stand biomass and forest disturbances, and an ecosystem carbon cycle model to assess contemporary forest carbon dynamics at a 30 m resolution. In this study, we evaluate the NFCMS estimates of biomass and carbon fluxes with available data …
Encoding A Categorical Independent Variable For Input To Terrset’S Multi-Layer Perceptron, Emily Evenden, Robert Gilmore Pontius
Encoding A Categorical Independent Variable For Input To Terrset’S Multi-Layer Perceptron, Emily Evenden, Robert Gilmore Pontius
Geography
The profession debates how to encode a categorical variable for input to machine learning algorithms, such as neural networks. A conventional approach is to convert a categorical variable into a collection of binary variables, which causes a burdensome number of correlated variables. TerrSet’s Land Change Modeler proposes encoding a categorical variable onto the continuous closed interval from 0 to 1 based on each category’s Population Evidence Likelihood (PEL) for input to the Multi-Layer Perceptron, which is a type of neural network. We designed examples to test the wisdom of these encodings. The results show that encoding a categorical variable based …
The Total Operating Characteristic From Stratified Random Sampling With An Application To Flood Mapping, Zhen Liu, Robert Gilmore Pontius
The Total Operating Characteristic From Stratified Random Sampling With An Application To Flood Mapping, Zhen Liu, Robert Gilmore Pontius
Geography
The Total Operating Characteristic (TOC) measures how the ranks of an index variable distinguish between presence and absence in a binary reference variable. Previous methods to generate the TOC required the reference data to derive from a census or a simple random sample. However, many researchers apply stratified random sampling to collect reference data because stratified random sampling is more efficient than simple random sampling for many applications. Our manuscript derives a new methodology that uses stratified random sampling to generate the TOC. An application to flood mapping illustrates how the TOC compares the abilities of three indices to diagnose …
A Near-Real-Time Approach For Monitoring Forest Disturbance Using Landsat Time Series: Stochastic Continuous Change Detection, Su Ye, John Rogan, Zhe Zhu, J. Ronald Eastman
A Near-Real-Time Approach For Monitoring Forest Disturbance Using Landsat Time Series: Stochastic Continuous Change Detection, Su Ye, John Rogan, Zhe Zhu, J. Ronald Eastman
Geography
Forest disturbances greatly affect the ecological functioning of natural forests. Timely information regarding extent, timing and magnitude of forest disturbance events is crucial for effective disturbance management strategies. Yet, we still lack accurate, near-real-time and high-performance remote sensing tools for monitoring abrupt and subtle forest disturbances. This study presents a new approach called ‘Stochastic Continuous Change Detection (S-CCD)’ using a dense Landsat data time series. S-CCD improves upon the ‘COntinuous monitoring of Land Disturbance (COLD)’ approach by incorporating a mathematical tool called the ‘state space model’, which treats trends and seasonality as stochastic processes, allowing for modeling temporal dynamics of …
Toward The Development Of Deep Learning Analyses For Snow Avalanche Releases In Mountain Regions, Yunzhi Chen, Wei Chen, Omid Rahmati, Fatemeh Falah, Dominik Kulakowski, Saro Lee, Fatemeh Rezaie, Mahdi Panahi, Aref Bahmani, Hamid Darabi, Ali Torabi Haghighi, Huiyuan Bian
Toward The Development Of Deep Learning Analyses For Snow Avalanche Releases In Mountain Regions, Yunzhi Chen, Wei Chen, Omid Rahmati, Fatemeh Falah, Dominik Kulakowski, Saro Lee, Fatemeh Rezaie, Mahdi Panahi, Aref Bahmani, Hamid Darabi, Ali Torabi Haghighi, Huiyuan Bian
Geography
Snow avalanches impose a considerable threat to infrastructure and human safety in snow bound mountain areas. Nevertheless, the spatial prediction of snow avalanches has received little research attention in many vulnerable parts of the world, particularly in developing countries. The present study investigates the applicability of a stand alone convolutional neural network (CNN) model, as a deep learning approach, along with two metaheuristic algorithms including grey wolf optimization (CNN-GWO) and imperialist competitive algorithm (CNN-ICA) in snow avalanche modelling in the Darvan watershed, Iran. The analysis was based on thirteen potential drivers of avalanche occurrence and an inventory map of previously …
Effects Of Bark Beetle Outbreaks On Forest Landscape Pattern In The Southern Rocky Mountains, U.S.A., Kyle C. Rodman, Robert A. Andrus, Cori L. Butkiewicz, Teresa B. Chapman, Nathan S. Gill, Brian J. Harvey, Dominik Kulakowski, Niko J. Tutland, Thomas T. Veblen, Sarah J. Hart
Effects Of Bark Beetle Outbreaks On Forest Landscape Pattern In The Southern Rocky Mountains, U.S.A., Kyle C. Rodman, Robert A. Andrus, Cori L. Butkiewicz, Teresa B. Chapman, Nathan S. Gill, Brian J. Harvey, Dominik Kulakowski, Niko J. Tutland, Thomas T. Veblen, Sarah J. Hart
Geography
Since the late 1990s, extensive outbreaks of native bark beetles (Curculionidae: Scolytinae) have affected coniferous forests throughout Europe and North America, driving changes in carbon storage, wildlife habitat, nutrient cycling, and water resource provisioning. Remote sensing is a cru-cial tool for quantifying the effects of these disturbances across broad landscapes. In particular, Landsat time series (LTS) are increasingly used to characterize outbreak dynamics, including the presence and severity of bark beetle-caused tree mortality, though broad-scale LTS-based maps are rarely informed by detailed field validation. Here we used spatial and temporal information from LTS products, in combination with extensive field data …
The Atmospheric Carbon And Transport (Act)-America Mission, Kenneth J. Davis, Edward V. Browell, Sha Feng, Thomas Lauvaux, Michael D. Obland, Sandip Pal, Bianca C. Baier, David F. Baker, Ian T. Baker, Zachary R. Barkley, Kevin W. Bowman, Yu Yan Cui, A. Scott Denning, Joshua P. Digangi, Jeremy T. Dobler, Alan Fried, Tobias Gerken, Klaus Keller, Bing Lin, Amin R. Nehrir, Caroline P. Normile, Christopher W. O'Dell, Lesley E. Ott, Anke Roiger, Andrew E. Schuh, Colm Sweeney, Yaxing Wei, Brad Weir, Ming Xue, Christopher A. Williams
The Atmospheric Carbon And Transport (Act)-America Mission, Kenneth J. Davis, Edward V. Browell, Sha Feng, Thomas Lauvaux, Michael D. Obland, Sandip Pal, Bianca C. Baier, David F. Baker, Ian T. Baker, Zachary R. Barkley, Kevin W. Bowman, Yu Yan Cui, A. Scott Denning, Joshua P. Digangi, Jeremy T. Dobler, Alan Fried, Tobias Gerken, Klaus Keller, Bing Lin, Amin R. Nehrir, Caroline P. Normile, Christopher W. O'Dell, Lesley E. Ott, Anke Roiger, Andrew E. Schuh, Colm Sweeney, Yaxing Wei, Brad Weir, Ming Xue, Christopher A. Williams
Geography
The Atmospheric Carbon and Transport (ACT)-America NASA Earth Venture Suborbital Mission set out to improve regional atmospheric greenhouse gas (GHG) inversions by exploring the intersection of the strong GHG fluxes and vigorous atmospheric transport that occurs within the midlatitudes. Two research aircraft instrumented with remote and in situ sensors to measure GHG mole fractions, associated trace gases, and atmospheric state variables collected 1,140.7 flight hours of research data, distributed across 305 individual aircraft sorties, coordinated within 121 research flight days, and spanning five 6-week seasonal flight campaigns in the central and eastern United States. Flights sampled 31 synoptic sequences, including …