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Physical Sciences and Mathematics Commons

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Full-Text Articles in Physical Sciences and Mathematics

Empirical Models For Predicting Water And Heat Flow Properties Of Permafrost Soils, Michael T. O'Connor, M. Bayani Cardenas, Stephen B. Ferencz, Yue Wu, Bethany T. Neilson, Jingyi Chen, George W. Kling May 2020

Empirical Models For Predicting Water And Heat Flow Properties Of Permafrost Soils, Michael T. O'Connor, M. Bayani Cardenas, Stephen B. Ferencz, Yue Wu, Bethany T. Neilson, Jingyi Chen, George W. Kling

Publications

Warming and thawing in the Arctic are promoting biogeochemical processing and hydrologic transport in carbon‐rich permafrost and soils that transfer carbon to surface waters or the atmosphere. Hydrologic and biogeochemical impacts of thawing are challenging to predict with sparse information on arctic soil hydraulic and thermal properties. We developed empirical and statistical models of soil properties for three main strata in the shallow, seasonally thawed soils above permafrost in a study area of ~7,500 km2 in Alaska. The models show that soil vertical stratification and hydraulic properties are predictable based on vegetation cover and slope. We also show that …


Ueb Parallel: Distributed Snow Accumulation And Melt Modeling Using Parallel Computing, Tseganeh Z. Gichamo, David G. Tarboton Dec 2019

Ueb Parallel: Distributed Snow Accumulation And Melt Modeling Using Parallel Computing, Tseganeh Z. Gichamo, David G. Tarboton

Publications

The Utah Energy Balance (UEB) model supports gridded simulation of snow processes over a watershed. To enhance computational efficiency, we developed two parallel versions of the model, one using the Message Passing Interface (MPI) and the other using NVIDIA's CUDA code on Graphics Processing Unit (GPU). Evaluation of the speed-up and efficiency of the MPI version shows that the effect of input/output (IO) operations on the parallel model performance increases as the number of processor cores increases. As a result, although the computation kernel scales well with the number of cores, the efficiency of the parallel code as a whole …


Ensemble Streamflow Forecasting Using An Energy Balance Snowmelt Model Coupled To A Distributed Hydrologic Model With Assimilation Of Snow And Streamflow Observations, Tseganeh Zekiewos Gichamo, David G. Tarboton Oct 2019

Ensemble Streamflow Forecasting Using An Energy Balance Snowmelt Model Coupled To A Distributed Hydrologic Model With Assimilation Of Snow And Streamflow Observations, Tseganeh Zekiewos Gichamo, David G. Tarboton

Publications

In many river basins across the world, snowmelt is an important source of streamflow. However, detailed snowmelt modeling is hampered by limited input data and uncertainty arising from inadequate model structure and parametrization. Data assimilation that updates model states based on observations, reduces uncertainty and improves streamflow forecasts. In this study, we evaluated the Utah Energy Balance (UEB) snowmelt model coupled to the Sacramento Soil Moisture Accounting (SAC‐SMA) and rutpix7 stream routing models, integrated within the Research Distributed Hydrologic Model (RDHM) framework for streamflow forecasting. We implemented an ensemble Kalman filter for assimilation of snow water equivalent (SWE) observations in …


Estimating Discharge In Low-Order Rivers With High-Resolution Aerial Imagery, Tyler V. King, Bethany T. Neilson, Mitchell T. Rasmussen Feb 2018

Estimating Discharge In Low-Order Rivers With High-Resolution Aerial Imagery, Tyler V. King, Bethany T. Neilson, Mitchell T. Rasmussen

Publications

Remote sensing of river discharge promises to augment in situ gauging stations, but the majority of research in this field focuses on large rivers (>50 m wide). We present a method for estimating volumetric river discharge in low-order (wide) rivers from remotely sensed data by coupling high-resolution imagery with one-dimensional hydraulic modeling at so-called virtual gauging stations. These locations were identified as locations where the river contracted under low flows, exposing a substantial portion of the river bed. Topography of the exposed river bed was photogrammetrically extracted from high-resolution aerial imagery while the geometry of the remaining inundated portion …


Monthly Paleostreamflow Reconstruction From Annual Tree-Ring Chronologies, James H. Stagge, David E. Rosenberg, R. J. Derose, Tammy M. Rittenour Feb 2018

Monthly Paleostreamflow Reconstruction From Annual Tree-Ring Chronologies, James H. Stagge, David E. Rosenberg, R. J. Derose, Tammy M. Rittenour

Publications

Paleoclimate reconstructions are increasingly used to characterize annual climate variability prior to the instrumental record, to improve estimates of climate extremes, and to provide a baseline for climate-change projections. To date, paleoclimate records have seen limited engineering use to estimate hydrologic risks because water systems models and managers usually require streamflow input at the monthly scale. This study explores the hypothesis that monthly streamflows can be adequately modeled by statistically decomposing annual flow reconstructions. To test this hypothesis, a multiple linear regression model for monthly streamflow reconstruction is presented that expands the set of predictors to include annual streamflow reconstructions, …