Social and Behavioral Sciences Commons^™

Towards More Equitable And Climate Resilient Communities With Jola Ajibade, Jola Ajibade

PDXPLORES Podcast

In this episode of PDXPLORES, Professor Jola Ajibade discusses research examining how cascading social and environmental hazards might impact communities in the Portland metro region and what policymakers and community members can do to mitigate the risks and promote a more just, livable, and sustainable urban future.

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The Influence Of Microsite Conditions On Early Performance Of Planted Nothofagus Nitida Seedlings When Restoring Degraded Coastal Temperate Rain Forests, Jan R. Bannister, Manuel Acevedo, German Travieso, Andres Holz, Nicole Galindo

Geography Faculty Publications and Presentations

Widespread impacts of changes in land use, climate, and disturbance regimes continue to affect mature forests and their subsequent post-disturbance recovery. In South American temperate rainforests, the recovery of the original composition, structure, and ecological services of now-degraded old-growth forests is additionally hampered by the aggressive competition that the native Chusquea bamboo understory exerts on juvenile trees, thus arresting ecological succession. In this study, we aim to evaluate the early performance of Nothofagus nitida seedlings (pioneer tree species that tolerate shade) planted beneath nurse canopy following removal of the understory, and to define which microsite conditions can facilitate N. nitida …

Combating Ecosystem Collapse From The Tropics To The Antarctic, Dana M. Bergstrom, Barbara C. Wienecke, John Van Den Hoff, Lesley Hughes, David B. Lindenmayer, Tracy D. Ainsworth, Christopher M. Baker, Lucie Bland, David M J S Bowman, Shaun T. Brooks, Josep G. Canadell, Andrew J. Constable, Katherine A. Dafforn, Michael H. Depledge, Catherine R. Dickson, Norman C. Duke, Kate J. Helmstedt, Andrés Holz

Geography Faculty Publications and Presentations

Globally, collapse of ecosystems-potentially irreversible change to ecosystem structure, composition and function-imperils biodiversity, human health and well-being. We examine the current state and recent trajectories of 19 ecosystems, spanning 58° of latitude across 7.7 M km , from Australia's coral reefs to terrestrial Antarctica. Pressures from global climate change and regional human impacts, occurring as chronic 'presses' and/or acute 'pulses', drive ecosystem collapse. Ecosystem responses to 5-17 pressures were categorised as four collapse profiles-abrupt, smooth, stepped and fluctuating. The manifestation of widespread ecosystem collapse is a stark warning of the necessity to take action. We present a three-step assessment and …

Stratospheric Polar Vortex Variability In The Northern Hemisphere: The Effects Of Climate Change On Polar Vortex Trends And Future Projections, John Earl Rogers

Dissertations and Theses

Regions that have experienced recent successive cold winters such as the Northeast of North America and Siberia have endured critical social and economic impacts from anomalous low temperatures in recent years, despite warming global temperatures. It is well known that the Tropospheric Polar Vortex (TPV), or jet stream, is a primary influence on many mid-latitude winter weather patterns. However, the strong circumpolar westerlies that maximize at around 60° latitude just above the tropopause, known as the Stratospheric Polar Vortex (SPV), can affect tropospheric circulation and thus winter weather in the Northern Hemisphere. Strong upward propagating waves can affect the geographic …

More Than The Sum Of Its Parts: How Disturbance Interactions Shape Forest Dynamics Under Climate Change, Melissa S. Lucash, Robert M. Scheller, Brian R. Sturtevant, Eric J. Gustafson, Alec M. Kretchun, Jane R. Foster

Geography Faculty Publications and Presentations

Interactions among disturbances are seldom quantified, and how they will be affected by climate change is even more uncertain. In this study, we sought to better understand how interactions among disturbances shift under climate change by applying a process-based landscape disturbance and succession model (LANDIS-II) to project disturbance regimes under climate change in north-central Minnesota, USA. Specifically, we (1) contrasted mortality rates and the extent of disturbance for four individual (single) disturbance regimes (fire, insects, wind, or forest management) vs. all four disturbance regimes operating simultaneously (concurrent) under multiple climate change scenarios and (2) determined how climate change interacts with …

Future Flooding Impacts On Transportation Infrastructure And Traffic Patterns Resulting From Climate Change, Heejun Chang, Martin Lafrenz, Il-Won Jung, Miguel A. Figliozzi, Rolando Melgoza, David Ruelas, Deena Platman, Cindy Pederson

Geography Faculty Publications and Presentations

This study investigated potential impacts of climate change on travel disruption resulting from road closures in two urban watersheds in the Portland metropolitan area. We used ensemble climate change scenarios, a hydrologic model, stream channel survey, a hydraulic model, and a travel forecast model to develop an integrated impact assessment method. High-resolution climate change scenarios are based on the combinations of two emission scenarios and eight general circulation models. The Precipitation-Runoff Modeling System was calibrated and validated for the period 1988-2006, and simulated for determining the probability of floods from 2020-2049. We surveyed stream cross sections at five road crossings …

Examining The Effects Of Climate Change And Urban Development On Water Demand: A Multi-Scale Analysis Of Future Water Demand In Hillsboro, Oregon, Lily Arielle House-Peters

Dissertations and Theses

In the Portland, Oregon, metropolitan area, suburban cities such as Hillsboro are projected to grow as people seek affordable housing near a rapidly growing metropolis. This thesis examines the combined impact of climate change and urban development on both neighborhood and municipal scale residential water demand in Hillsboro, Oregon. I use two models, a surface energy balance model, Local-scale Urban Meteorological Parameterization Scheme (LUMPS), and a system dynamics model, CCDomestic, to investigate changes in residential water demand in the 2040s at two distinct spatial scales, the neighborhood and the municipality. I calibrate and validate each model to the reference period …

Climatic And Spatial Variations Of Mount Rainier's Glaciers For The Last 12,000 Years, Michael Leslie Hekkers

Dissertations and Theses

Regional paleoclimatic proxies and current local climate variables and were analyzed to reconstruct paleoglaciers in an effort to assess glacier change On Mount Rainier. Despite the dry and generally warm conditions (sea surface temperatures (SST) -0.15°C to +1.8°C relative to current temperatures), the previously documented McNeeley II advance (10,900 - 9,950 cal yr B.P.) was likely produced by air temperature fluctuations. The average SST record and the terrestrial climate proxies show cooling temperatures with continued dryness between McNeeley II and the Burroughs Mountain advance (3,442 - 2,153 cal yr B.P.). The paleoclimate during the Burroughs Mountain advance was both cool …

Water As A Complex System: Understanding The Dynamics In A Changing Environment, Heejun Chang

Systems Science Friday Noon Seminar Series

The water resources system is constantly evolving over space and time at a range of scales. Human-induced climate change and land development are probably two major driving forces of water resource system changes. However, the impacts of such changes are region specific, which depend on watershed characteristics such as topography and geology. Numerical simulation models are useful tools for understanding the system dynamics by allowing the multiple interactions of system components. I will introduce case studies of the Pacific Northwest that examine how changing climate and population growth affect regional water resources at multiple spatial and temporal scales and explain …

Impacts Of Climate Change And Urban Development On Water Resources In The Tualatin River Basin, Sarah Praskievicz

Dissertations and Theses

Potential impacts of climate change on the water resources of the Pacific Northwest of the United States include earlier peak runoff, reduced summer flows, and increased winter flooding. An increase in impervious surfaces, accompanied by urban development, is known to decrease infiltration and increase surface runoff. Alterations of flow amount and pathways can alter water quality through dilution or flushing effects. I used the United States Environmental Protection Agency's Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) modeling system to investigate the relative importance of future climate change and land use change in determining the quantity and quality of …

The Effects Of Climate Change And Urbanization On The Runoff Of The Rock Creek Basin, Jon J. Franczyk

Dissertations and Theses

Climate changes brought on by global warming are expected to have a significant affect on the Pacific Northwest hydrology during the 21^st Century. Current research anticipates higher mean annual temperatures and an intensification of the hydrological cycle. This is of particular concern for highly urbanized basins, which are considered more vulnerable to changes in climate. Because the majority of previous studies have addressed the influences of either climate or urban land cover changes on runoff, there is a lack of research investigating the combined effect of these factors. The Rock Creek basin (RCB), located in the Portland, OR, metropolitan …

Quantifying Twentieth Century Glacier Change In The Sierra Nevada, California, Hassan J. Basagic

Dissertations and Theses

Numerous small alpine glaciers occupy the high elevation regions of the central and southern Siena Nevada, California. These glaciers change size in response to variations in climate and are therefore important indicators of climate change. An inventory based on USGS topographic maps (l :24,000) revealed 1719 glaciers and perennial snow and ice features for a total area of 39.l5 ±7.52 km². The number of 'true' glaciers, versus non-moving ice, is estimated to be 118, covering 15.87 ± 1.69 Km². All glaciers were located on north to northeast aspects, at elevations >3000 m. Historical photographs, geologic evidence, …