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Full-Text Articles in Physical Sciences and Mathematics
Watershed Response To Climate Change And Fire-Burns In The Upper Umatilla River Basin, Usa, Kimberly Crystal Yazzie, Heejun Chang
Watershed Response To Climate Change And Fire-Burns In The Upper Umatilla River Basin, Usa, Kimberly Crystal Yazzie, Heejun Chang
Geography Faculty Publications and Presentations
This study analyzed watershed response to climate change and forest fire impacts in the upper Umatilla River Basin (URB), Oregon, using the precipitation runoff modeling system. Ten global climate models using Coupled Intercomparison Project Phase 5 experiments with Representative Concentration Pathways (RCP) 4.5 and 8.5 were used to simulate the effects of climate and fire-burns on runoff behavior throughout the 21st century. We observed the center timing (CT) of flow, seasonal flows, snow water equivalent (SWE) and basin recharge. In the upper URB, hydrologic regime shifts from a snow-rain-dominated to rain-dominated basin. Ensemble mean CT occurs 27 days earlier in …
Utilizing Humidity And Temperature Data To Advance Monitoring And Prediction Of Meteorological Drought, Ali Behrangi, Paul C. Loikith, Eric J. Fetzer, Hai M. Nguyen, Stephanie L. Granger
Utilizing Humidity And Temperature Data To Advance Monitoring And Prediction Of Meteorological Drought, Ali Behrangi, Paul C. Loikith, Eric J. Fetzer, Hai M. Nguyen, Stephanie L. Granger
Geography Faculty Publications and Presentations
The fraction of land area over the Continental United States experiencing extreme hot and dry conditions has been increasing over the past several decades, consistent with expectation from anthropogenic climate change. A clear concurrent change in precipitation, however, has not been confirmed. Vapor pressure deficit (VPD), combining temperature and humidity, is utilized here as an indicator of the background atmospheric conditions associated with meteorological drought. Furthermore, atmospheric conditions associated with warm season drought events are assessed by partitioning associated VPD anomalies into the temperature and humidity components. This approach suggests that the concurrence of anomalously high temperature and low humidity …
Quantifying Uncertainty In Urban Flooding Analysis Considering Hydro-Climatic Projection And Urban Development Effects, Il-Won Jung, Heejun Chang, Hamid Moradkhani
Quantifying Uncertainty In Urban Flooding Analysis Considering Hydro-Climatic Projection And Urban Development Effects, Il-Won Jung, Heejun Chang, Hamid Moradkhani
Geography Faculty Publications and Presentations
How will the combined impacts of land use change, climate change, and hydrologic modeling influence changes in urban flood frequency and what is the main uncertainty source of the results? Will such changes differ by catchment with different degrees of current and future urban development? We attempt to answer these questions in two catchments with different degrees of urbanization, the Fanno catchment with 84% urban land use and the Johnson catchment with 36% urban land use, both located in the Pacific Northwest of the US. Five uncertainty sources – general circulation model (GCM) structures, future greenhouse gas (GHG) emission scenarios, …
Winter Precipitation Intensity And Enso/Pdo Variability In The Willamette Valley Of Oregon, Sarah Praskievicz, Heejun Chang
Winter Precipitation Intensity And Enso/Pdo Variability In The Willamette Valley Of Oregon, Sarah Praskievicz, Heejun Chang
Geography Faculty Publications and Presentations
There is growing concern about the effects of inter-annual climatic variability, such as the El-Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO), on regional hydrology and water resources. We analyzed patterns of wintertime precipitation intensity, using both simple intensity and number of heavy precipitation days per year, for eight stations in northwestern Oregon’s Willamette Valley for the period 1972–2006, and examined the separate and combined influence of ENSO and PDO on precipitation intensity. The analysis was accomplished using Kendall’s tau and analysis of variance (ANOVA) to determine differences in precipitation intensity among combinations of positive and negative ENSO …