Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

Remote Sensing Of Water Use Efficiency And Terrestrial Drought Recovery Across The Contiguous United States, Behzad Ahmadi, Ali Ahmadalipour, Glenn Tootle Mar 2019

Remote Sensing Of Water Use Efficiency And Terrestrial Drought Recovery Across The Contiguous United States, Behzad Ahmadi, Ali Ahmadalipour, Glenn Tootle

Civil and Environmental Engineering Faculty Publications and Presentations

Ecosystem water-use efficiency (WUE) is defined as the ratio of carbon gain (i.e., gross primary productivity; GPP) to water consumption (i.e., evapotranspiration; ET). WUE is markedly influential on carbon and water cycles, both of which are fundamental for ecosystem state, climate and the environment. Drought can affect WUE, subsequently disturbing the composition and functionality of terrestrial ecosystems. In this study, the impacts of drought on WUE and its components (i.e., GPP and ET) are assessed across the Contiguous US (CONUS) at fine spatial and temporal resolutions. Soil moisture simulations from land surface modeling are utilized to detect and characterize agricultural …


Mechanics And Historical Evolution Of Sea Level Blowouts In New York Harbor, Praneeth Gurumurthy, Philip Orton, Stefan A. Talke, Nickitas Georgas, James F. Booth Jan 2019

Mechanics And Historical Evolution Of Sea Level Blowouts In New York Harbor, Praneeth Gurumurthy, Philip Orton, Stefan A. Talke, Nickitas Georgas, James F. Booth

Civil and Environmental Engineering Faculty Publications and Presentations

Wind-induced sea level blowouts, measured as negative storm surge or extreme low water (ELW), produce public safety hazards and impose economic costs (e.g., to shipping). In this paper, we use a regional hydrodynamic numerical model to test the effect of historical environmental change and the time scale, direction, and magnitude of wind forcing on negative and positive surge events in the New York Harbor (NYH). Environmental sensitivity experiments show that dredging of shipping channels is an important factor affecting blowouts while changing ice cover and removal of other roughness elements are unimportant in NYH. Continuously measured water level records since …


Bigger Tides, Less Flooding: Effects Of Dredging On Barotropic Dynamics In A Highly Modified Estuary, David K. Ralston, Stefan Talke, W. Rockwell Geyer, Hussein A. M. Al-Zubaidi, Christopher K. Sommerfield Jan 2019

Bigger Tides, Less Flooding: Effects Of Dredging On Barotropic Dynamics In A Highly Modified Estuary, David K. Ralston, Stefan Talke, W. Rockwell Geyer, Hussein A. M. Al-Zubaidi, Christopher K. Sommerfield

Civil and Environmental Engineering Faculty Publications and Presentations

Since the late nineteenth century, channel depths have more than doubled in parts of New York Harbor and the tidal Hudson River, wetlands have been reclaimed and navigational channels widened, and river flow has been regulated. To quantify the effects of these modifications, observations and numerical simulations using historical and modern bathymetry are used to analyze changes in the barotropic dynamics. Model results and water level records for Albany (1868 to present) and New York Harbor (1844 to present) recovered from archives show that the tidal amplitude has more than doubled near the head of tides, whereas increases in the …


Effects Of Water Level Fluctuation On Thermal Stratification In A Typical Tributary Bay Of Three Gorges Reservoir, China, Juxiang Jin, Scott Wells, Defu Liu, Guolu Yang, Senlin Zhu, Jun Ma, Zhengjian Yang Jan 2019

Effects Of Water Level Fluctuation On Thermal Stratification In A Typical Tributary Bay Of Three Gorges Reservoir, China, Juxiang Jin, Scott Wells, Defu Liu, Guolu Yang, Senlin Zhu, Jun Ma, Zhengjian Yang

Civil and Environmental Engineering Faculty Publications and Presentations

Xiangxi River is a typical tributary of Three Gorges Reservoir (TGR) in China. Based on field observations in 2010, thermal stratification was significant in most months of the year. Through field data analysis and numerical simulations, the seasonal and spatial variation of thermal stratification as related to the impact of the operation of TGR were investigated. Thermal stratification was most pronounced from April to September in the Xiangxi River tributary. Air temperature (AT) and water level (WL) were the two dominant variables impacting thermal stratification. AT affected the surface water temperature promoting the formation of thermal stratification, and high WLs …


Improved Drought Resilience Through Continuous Water Service Monitoring And Specialized Institutions—A Longitudinal Analysis Of Water Service Delivery Across Motorized Boreholes In Northern Kenya, Nick Turman-Bryant, Corey L. Nagel, Lauren Stover, Christian Muragijimana, Evan A. Thomas Jan 2019

Improved Drought Resilience Through Continuous Water Service Monitoring And Specialized Institutions—A Longitudinal Analysis Of Water Service Delivery Across Motorized Boreholes In Northern Kenya, Nick Turman-Bryant, Corey L. Nagel, Lauren Stover, Christian Muragijimana, Evan A. Thomas

Systems Science Faculty Publications and Presentations

Increasing frequency and severity of drought is driving increased use of groundwater resources in arid regions of Northern Kenya, where approximately 2.5 million people depend on groundwater for personal use, livestock, and limited irrigation. As part of a broader effort to provide more sustainable water, sanitation, and hygiene services in the region, we have collected data related to site functionality and use for approximately 120 motorized boreholes across five counties. Using a multilevel model to account for geospatial and temporal clustering, we found that borehole sites, which counties had identified as strategic assets during drought, ran on average about 1.31 …


Floodplains Provide Important Amphibian Habitat Despite Multiple Ecological Threats, Meredith Holgerson, Adam Duarte, Marc P. Hayes, Michael J. Adams, Julie A. Tyson, Keith A. Douville, Angela L. Strecker Jan 2019

Floodplains Provide Important Amphibian Habitat Despite Multiple Ecological Threats, Meredith Holgerson, Adam Duarte, Marc P. Hayes, Michael J. Adams, Julie A. Tyson, Keith A. Douville, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

Floodplain ponds and wetlands are productive and biodiverse ecosystems, yet they face multiple threats including altered hydrology, land use change, and non-native species. Protecting and restoring important floodplain ecosystems requires understanding how organisms use these habitats and respond to altered environmental conditions. We developed Bayesian models to evaluate occupancy of six amphibian species across 103 off-channel aquatic habitats in the Chehalis River floodplain, Washington State, USA. The basin has been altered by changes in land use, reduced river–wetland connections, and the establishment of non-native American bullfrogs (Rana catesbeiana = Lithobates catesbeianus) and centrarchid fishes, all of which we hypothesized could …