scholarly journals Statistical Comparisons of Watershed-Scale Response to Climate Change in Selected Basins across the United States

2011 ◽  
Vol 15 (14) ◽  
pp. 1-26 ◽  
Author(s):  
John Risley ◽  
Hamid Moradkhani ◽  
Lauren Hay ◽  
Steve Markstrom
Keyword(s):  
Climate Change ◽  
United States ◽  
The United States ◽  
First Century ◽  
Energy Output ◽  
Daily Streamflow ◽  
Watershed Models ◽  
Monthly Streamflow ◽  
Twenty First Century ◽  
The Impact

Abstract In an earlier global climate-change study, air temperature and precipitation data for the entire twenty-first century simulated from five general circulation models were used as input to precalibrated watershed models for 14 selected basins across the United States. Simulated daily streamflow and energy output from the watershed models were used to compute a range of statistics. With a side-by-side comparison of the statistical analyses for the 14 basins, regional climatic and hydrologic trends over the twenty-first century could be qualitatively identified. Low-flow statistics (95% exceedance, 7-day mean annual minimum, and summer mean monthly streamflow) decreased for almost all basins. Annual maximum daily streamflow also decreased in all the basins, except for all four basins in California and the Pacific Northwest. An analysis of the supply of available energy and water for the basins indicated that ratios of evaporation to precipitation and potential evapotranspiration to precipitation for most of the basins will increase. Probability density functions (PDFs) were developed to assess the uncertainty and multimodality in the impact of climate change on mean annual streamflow variability. Kolmogorov–Smirnov tests showed significant differences between the beginning and ending twenty-first-century PDFs for most of the basins, with the exception of four basins that are located in the western United States. Almost none of the basin PDFs were normally distributed, and two basins in the upper Midwest had PDFs that were extremely dispersed and skewed.

scholarly journals Watershed-Scale Response to Climate Change through the Twenty-First Century for Selected Basins across the United States

2011 ◽  
Vol 15 (17) ◽  
pp. 1-37 ◽  
Author(s):  
Lauren E. Hay ◽  
Steven L. Markstrom ◽  
Christian Ward-Garrison
Keyword(s):  
Climate Change ◽  
United States ◽  
Coupled Model ◽  
The United States ◽  
Lessons Learned ◽  
First Century ◽  
Emission Scenarios ◽  
Watershed Model ◽  
Geographical Regions ◽  
Twenty First Century

Abstract The hydrologic response of different climate-change emission scenarios for the twenty-first century were evaluated in 14 basins from different hydroclimatic regions across the United States using the Precipitation-Runoff Modeling System (PRMS), a process-based, distributed-parameter watershed model. This study involves four major steps: 1) setup and calibration of the PRMS model in 14 basins across the United States by local U.S. Geological Survey personnel; 2) statistical downscaling of the World Climate Research Programme’s Coupled Model Intercomparison Project phase 3 climate-change emission scenarios to create PRMS input files that reflect these emission scenarios; 3) run PRMS for the climate-change emission scenarios for the 14 basins; and 4) evaluation of the PRMS output. This paper presents an overview of this project, details of the methodology, results from the 14 basin simulations, and interpretation of these results. A key finding is that the hydrological response of the different geographical regions of the United States to potential climate change may be very different, depending on the dominant physical processes of that particular region. Also considered is the tremendous amount of uncertainty present in the climate emission scenarios and how this uncertainty propagates through the hydrologic simulations. This paper concludes with a discussion of the lessons learned and potential for future work.

Characterizing Climate-Change Impacts on the 1.5-yr Flood Flow in Selected Basins across the United States: A Probabilistic Approach

2011 ◽  
Vol 15 (18) ◽  
pp. 1-16 ◽  
Author(s):  
John F. Walker ◽  
Lauren E. Hay ◽  
Steven L. Markstrom ◽  
Michael D. Dettinger
Keyword(s):  
Climate Change ◽  
United States ◽  
Probabilistic Approach ◽  
The United States ◽  
Empirical Orthogonal Functions ◽  
First Century ◽  
Climate Projections ◽  
Climate Change Scenarios ◽  
Twenty First Century ◽  
Temporal Shifts

Abstract The U.S. Geological Survey Precipitation-Runoff Modeling System (PRMS) model was applied to basins in 14 different hydroclimatic regions to determine the sensitivity and variability of the freshwater resources of the United States in the face of current climate-change projections. Rather than attempting to choose a most likely scenario from the results of the Intergovernmental Panel on Climate Change, an ensemble of climate simulations from five models under three emissions scenarios each was used to drive the basin models. Climate-change scenarios were generated for PRMS by modifying historical precipitation and temperature inputs; mean monthly climate change was derived by calculating changes in mean climates from current to various future decades in the ensemble of climate projections. Empirical orthogonal functions (EOFs) were fitted to the PRMS model output driven by the ensemble of climate projections and provided a basis for randomly (but representatively) generating realizations of hydrologic response to future climates. For each realization, the 1.5-yr flood was calculated to represent a flow important for sediment transport and channel geomorphology. The empirical probability density function (pdf) of the 1.5-yr flood was estimated using the results across the realizations for each basin. Of the 14 basins studied, 9 showed clear temporal shifts in the pdfs of the 1.5-yr flood projected into the twenty-first century. In the western United States, where the annual peak discharges are heavily influenced by snowmelt, three basins show at least a 10% increase in the 1.5-yr flood in the twenty-first century; the remaining two basins demonstrate increases in the 1.5-yr flood, but the temporal shifts in the pdfs and the percent changes are not as distinct. Four basins in the eastern Rockies/central United States show at least a 10% decrease in the 1.5-yr flood; the remaining two basins demonstrate decreases in the 1.5-yr flood, but the temporal shifts in the pdfs and the percent changes are not as distinct. Two basins in the eastern United States show at least a 10% decrease in the 1.5-yr flood; the remaining basin shows little or no change in the 1.5-yr flood.

Biosurveillance: A Modern Look

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
James Lee Brooks
Keyword(s):  
United States ◽  
Homeland Security ◽  
The United States ◽  
First Century ◽  
Direct Result ◽  
Current State ◽  
Twenty First Century ◽  
Security Operations

AbstractThe early part of the twenty-first century saw a revolution in the field of Homeland Security. The 9/11 attacks, shortly followed thereafter by the Anthrax Attacks, served as a wakeup call to the United States and showed the inadequacy of the current state of the nation’s Homeland Security operations. Biodefense, and as a direct result Biosurveillance, changed dramatically after these tragedies, planting the seeds of fear in the minds of Americans. They were shown that not only could the United States be attacked at any time, but the weapon could be an invisible disease-causing agent.

Conclusion: Sincerity Dreams

2017 ◽  
Author(s):  
Ellen Rutten
Keyword(s):  
United States ◽  
Popular Culture ◽  
Western Europe ◽  
The United States ◽  
First Century ◽  
Contemporary Culture ◽  
Cultural Paradigms ◽  
Twenty First Century ◽  
Inclusive Analysis

This conclusion reflects on today's dreams of renewing or revitalizing sincerity and rejects the notion that they are outdated or do not deserve any of our attention. It cites the work of several scholars to show that sincerity is anything but obsolete in twenty-first-century popular culture. Indeed, today's strivings to renew sincerity have not been neglected by scholars such as R. Jay Magill Jr., Epstein, and Yurchak. The rhetoric on new sincerity has been addressed in thoughtful analyses of contemporary culture that have helped the author in crafting a comprehensive and geographically inclusive analysis of present-day sincerity rhetoric. In post-Communist Russia, debates on a shift to late or post-postmodern cultural paradigms are thriving with at least as much fervor as—and possibly more than—in Western Europe or the United States. This conclusion discusses the newly gained insights which the author's sincerity study offers.

The United States and the Americas: A Twenty-First-Century View

1999 ◽  
Vol 78 (5) ◽  
pp. 178 ◽  
Author(s):  
Kenneth Maxwell ◽  
Albert Fishlow ◽  
James Jones
Keyword(s):  
United States ◽  
The United States ◽  
First Century ◽  
Twenty First Century
Sign in / Sign up

Export Citation Format

Share Document