Engineering Commons^™

Catchment Processes Can Amplify The Effect Of Increasing Rainfall Variability, Marc F. Müller, Kevin R. Roche, David N. Dralle

Civil Engineering Faculty Publications and Presentations

By filtering the incoming climate signal when producing streamflow, river basins can attenuate—or amplify—projected increases in rainfall variability. A common perception is that river systems dampen rainfall variability by averaging spatial and temporal variations in their watersheds. However, by analyzing 671 watersheds throughout the United States, we find that many catchments actually amplify the coefficient of variation of rainfall, and that these catchments also likely amplify changes in rainfall variability. Based on catchment-scale water balance principles, we relate that faculty to the interplay between two fundamental hydrological processes: water uptake by vegetation and the storage and subsequent release of water …

Warming Enabled Upslope Advance In Western Us Forest Fires, Mohammad Reza Alizadeh, John T. Abatzoglou, Charles H. Luce, Jan F. Adamowski, Arvin Farid, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Increases in burned area and large fire occurrence are widely documented over the western United States over the past half century. Here, we focus on the elevational distribution of forest fires in mountainous ecoregions of the western United States and show the largest increase rates in burned area above 2,500 m during 1984 to 2017. Furthermore, we show that high-elevation fires advanced upslope with a median cumulative change of 252 m (−107 to 656 m; 95% CI) in 34 y across studied ecoregions. We also document a strong interannual relationship between high-elevation fires and warm season vapor pressure deficit (VPD). …

Western Fires Are Burning Higher In The Mountains At Unprecedented Rates: It’S A Clear Sign Of Climate Change, Mojtaba Sadegh, John Abatzoglou, Mohammad Reza Alizadeh

Civil Engineering Faculty Publications and Presentations

The Western U.S. appears headed for another dangerous fire season, and a new study shows that even high mountain areas once considered too wet to burn are at increasing risk as the climate warms.

Nearly two-thirds of the U.S. West is in severe to exceptional drought right now, including large parts of the Rocky Mountains, Cascades and Sierra Nevada. The situation is so severe that the Colorado River basin is on the verge of its first official water shortage declaration, and forecasts suggest another hot, dry summer is on the way.

Warm and dry conditions like these are a recipe …

Another Dangerous Fire Season Is Looming In The Western U.S., And The Drought-Stricken Region Is Headed For A Water Crisis, Mojtaba Sadegh, Amir Aghakouchak, John Abatzoglou

Civil Engineering Faculty Publications and Presentations

Just about every indicator of drought is flashing red across the western U.S. after a dry winter and warm early spring. The snowpack is at less than half of normal in much of the region. Reservoirs are being drawn down, river levels are dropping and soils are drying out.

It’s only May, and states are already considering water use restrictions to make the supply last longer. California’s governor declared a drought emergency in 41 of 58 counties. In Utah, irrigation water providers are increasing fines for overuse. Some Idaho ranchers are talking about selling off livestock because rivers and reservoirs …

Pooling Data Improves Multimodel Idf Estimates Over Median-Based Idf Estimates: Analysis Over The Susquehanna And Florida, Abhishekh Kumar Srivastava, Richard Grotjahn, Paul Aaron Ullrich, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Traditional multimodel methods for estimating future changes in precipitation intensity, duration, and frequency (IDF) curves rely on mean or median of models’ IDF estimates. Such multimodel estimates are impaired by large estimation uncertainty, shadowing their efficacy in planning efforts. Here, assuming that each climate model is one representation of the underlying data generating process, i.e., the Earth system, we propose a novel extension of current methods through pooling model data: (i) evaluate performance of climate models in simulating the spatial and temporal variability of the observed annual maximum precipitation (AMP), (ii) bias-correct and pool historical and future AMP data of …