Engineering Commons^™

Interdependencies Between Wildfire-Induced Alterations In Soil Properties, Near-Surface Processes, And Geohazards, Farshid Vahedifard, Masood Abdollahi, Ben A. Leshchinsky, Timothy D. Stark, Mojtaba Sadegh, Amir Aghakouchak

Civil Engineering Faculty Publications and Presentations

The frequency, severity, and spatial extent of destructive wildfires have increased in several regions globally over the past decades. While direct impacts from wildfires are devastating, the hazardous legacy of wildfires affects nearby communities long after the flames have been extinguished. Post-wildfire soil conditions control the persistence, severity, and timing of cascading geohazards in burned landscapes. The interplay and feedback between geohazards and wildfire-induced changes to soil properties, land cover conditions, and near-surface and surface processes are still poorly understood. Here, we synthesize wildfire-induced processes that can affect the critical attributes of burned soils and their conditioning of subsequent geohazards. …

Statistical And Deep Learning Models For Reference Evapotranspiration Time Series Forecasting: A Comparison Of Accuracy, Complexity, And Data Efficiency, Arman Ahmadi, Andre Daccache, Mojtaba Sadegh, Richard L. Snyder

Civil Engineering Faculty Publications and Presentations

Reference evapotranspiration (ETo) is an essential variable in agricultural water resources management and irrigation scheduling. An accurate and reliable forecast of ETo facilitates effective decision-making in agriculture. Although numerous studies assessed various methodologies for ETo forecasting, an in-depth multi-dimensional analysis evaluating different aspects of these methodologies is missing. This study systematically evaluates the complexity, computational cost, data efficiency, and accuracy of ten models that have been used or could potentially be used for ETo forecasting. These models range from well-known statistical forecasting models like seasonal autoregressive integrated moving average (SARIMA) to state-of-the-art deep learning (DL) algorithms like temporal fusion transformer …

Social Vulnerability Of The People Exposed To Wildfires In U.S. West Coast States, Arash Modaresi Rad, John T. Abatzoglou, Erica Fleishman, Miranda H. Mockrin, Volker C. Radeloff, Yavar Pourmohamad, Megan Cattau, J. Michael Johnson, Philip Higuera, Nicholas J. Nauslar, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Understanding of the vulnerability of populations exposed to wildfires is limited. We used an index from the U.S. Centers for Disease Control and Prevention to assess the social vulnerability of populations exposed to wildfire from 2000–2021 in California, Oregon, and Washington, which accounted for 90% of exposures in the western United States. The number of people exposed to fire from 2000–2010 to 2011–2021 increased substantially, with the largest increase, nearly 250%, for people with high social vulnerability. In Oregon and Washington, a higher percentage of exposed people were highly vulnerable (>40%) than in California (~8%). Increased social vulnerability of …

Shrinkage And Consolidation Characteristics Of Chitosan-Amended Soft Soil: A Sustainable Alternate Landfill Liner Material, Romana Mariyam Rasheed, Arif Ali Baig Moghal, Sai Sampreeth Reddy Jannepally, Ateekh Ur Rehman, Bhaskar C. S. Chittoori

Civil Engineering Faculty Publications and Presentations

Kuttanad is a region that lies in the southwest part of Kerala, India, and possesses soft soil, which imposes constraints on many civil engineering applications owing to low shear strength and high compressibility. Chemical stabilizers such as cement and lime have been extensively utilized in the past to address compressibility issues. However, future civilizations will be extremely dependent on the development of sustainable materials and practices such as the use of bio-enzymes, calcite precipitation methods, and biological materials as a result of escalating environmental concerns due to carbon emissions of conventional stabilizers. One such alternative is the utilization of biopolymers. …

Machine Learning-Enabled Regional Multi-Hazards Risk Assessment Considering Social Vulnerability, Tianjie Zhang, Donglei Wang, Yang Lu

Civil Engineering Faculty Publications and Presentations

The regional multi-hazards risk assessment poses difficulties due to data access challenges, and the potential interactions between multi-hazards and social vulnerability. For better natural hazards risk perception and preparedness, it is important to study the nature-hazards risk distribution in different areas, specifically a major priority in the areas of high hazards level and social vulnerability. We propose a multi-hazards risk assessment method which considers social vulnerability into the analyzing and utilize machine learning-enabled models to solve this issue. The proposed methodology integrates three aspects as follows: (1) characterization and mapping of multi-hazards (Flooding, Wildfires, and Seismic) using five machine learning …

Application Of Connected Vehicle Data To Assess Safety On Roadways, Mandar Khanal, Nathaniel Edelmann

Civil Engineering Faculty Publications and Presentations

Using surrogate safety measures is a common method to assess safety on roadways. Surrogate safety measures allow for proactive safety analysis; the analysis is performed prior to crashes occurring. This allows for safety improvements to be implemented proactively to prevent crashes and the associated injuries and property damage. Existing surrogate safety measures primarily rely on data generated by microsimulations, but the advent of connected vehicles has allowed for the incorporation of data from actual cars into safety analysis with surrogate safety measures. In this study, commercially available connected vehicle data are used to develop crash prediction models for crashes at …

Unconventional Water Resources: Global Opportunities And Challenges, Zahra Karimidastenaei, Tamara Avellán, Mojtaba Sadegh, Bjørn Kløve, Ali Torabi Haghighi

Civil Engineering Faculty Publications and Presentations

Water is of central importance for reaching the Sustainable Development Goals (SDGs) of the United Nations. With predictions of dire global water scarcity, attention is turning to resources that are considered to be unconventional, and hence called Unconventional Water Resources (UWRs). These are considered as supplementary water resources that need specialized processes to be used as water supply. The literature encompasses a vast number of studies on various UWRs and their usefulness in certain environmental and/or socio-economic contexts. However, a recent, all-encompassing article that brings the collective knowledge on UWRs together is missing. Considering the increasing importance of UWRs in …

Discrepancies In Changes In Precipitation Characteristics Over The Contiguous United States Based On Six Daily Gridded Precipitation Datasets, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Variability and spatiotemporal changes in precipitation characteristics can have profound socioenvironmental impacts. Several studies have shown that the frequency and/or magnitude of precipitation events have changed over the contiguous United States (CONUS) in the past decades. Most previous studies used only one precipitation dataset and only investigated mean or extreme precipitation. Here, using 6 gridded daily precipitation datasets, we show that there are substantial discrepancies in the changes in characteristics of both extreme and non-extreme precipitation events from 1983 to 2017. Our results highlight that using a single record to study precipitation changes can potentially lead to biased results. Using …

Coevolution Of Machine Learning And Process-Based Modelling To Revolutionize Earth And Environmental Sciences: A Perspective, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Machine learning (ML) applications in Earth and environmental sciences (EES) have gained incredible momentum in recent years. However, these ML applications have largely evolved in ‘isolation’ from the mechanistic, process-based modelling (PBM) paradigms, which have historically been the cornerstone of scientific discovery and policy support. In this perspective, we assert that the cultural barriers between the ML and PBM communities limit the potential of ML, and even its ‘hybridization’ with PBM, for EES applications. Fundamental, but often ignored, differences between ML and PBM are discussed as well as their strengths and weaknesses in light of three overarching modelling objectives in …

Novel Damage Index-Based Rapid Evaluation Of Civil Infrastructure Subsurface Defects Using Thermography Analytics, Tianjie Zhang, Md Asif Rahman, Alex Peterson, Yang Lu

Civil Engineering Faculty Publications and Presentations

The qualitative measurement is a common practice in infrastructure condition inspection when using Infrared Thermography (IRT), as it can effectively locate the defected area non-destructively and non-contact. However, a quantitative evaluation becomes more significant because it can help decision makers figure out specific compensation plans to deal with defects. In this work, an IRT-based novel damage index, damage density, was proposed to quantify the significance of subsurface defects. This index is extracted from IR images using our thermography analytics framework. The proposed framework includes thermal image processing, defect edge detection, and thermal gradient map calculations. A modified root mean square …

Benthic Biolayer Structure Controls Whole-Stream Reactive Transport, Kevin R. Roche, Marco Dentz

Civil Engineering Faculty Publications and Presentations

Hyporheic zone reaction rates are highest just below the sediment-water interface, in a shallow region called the benthic biolayer. Vertical variability of hyporheic reaction rates leads to unexpected reaction kinetics for stream-borne solutes, compared to classical model predictions. We show that deeper, low-reactivity locations within the hyporheic zone retain solutes for extended periods, which delays reactions and causes solutes to persist at higher concentrations in the stream reach than would be predicted by classical approaches. These behaviors are captured by an upscaled model that reveals the fundamental physical and chemical processes in the hyporheic zone. We show how time scales …

Groundwater Level Modeling With Machine Learning: A Systematic Review And Meta-Analysis, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Groundwater is a vital source of freshwater, supporting the livelihood of over two billion people worldwide. The quantitative assessment of groundwater resources is critical for sustainable management of this strained resource, particularly as climate warming, population growth, and socioeconomic development further press the water resources. Rapid growth in the availability of a plethora of in-situ and remotely sensed data alongside advancements in data-driven methods and machine learning offer immense opportunities for an improved assessment of groundwater resources at the local to global levels. This systematic review documents the advancements in this field and evaluates the accuracy of various models, following …

Copulas For Hydroclimatic Analysis: A Practice-Oriented Overview, Faranak Tootoonchi, Mojtaba Sadegh, Jan Olaf Haerter, Olle Räty, Thomas Grabs, Claudia Teutschbein

Civil Engineering Faculty Publications and Presentations

A warming climate is associated with increasing hydroclimatic extremes, which are often interconnected through complex processes, prompting their concurrence and/or succession, and causing compound extreme events. It is critical to analyze the risks of compound events, given their disproportionately high adverse impacts. To account for the variability in two or more hydroclimatic variables (e.g., temperature and precipitation) and their dependence, a rising number of publications focuses on multivariate analysis, among which the notion of copula-based probability distribution has attracted tremendous interest. Copula is a mathematical function that expresses the joint cumulative probability distribution of multiple variables. Our focus is to …

Increasing Heat-Stress Inequality In A Warming Climate, Mohammad Reza Alizadeh, John T. Abatzoglou, Jan F. Adamowski, Jeffrey P. Prestemon, Bhaskar Chittoori, Ata Akbari Asanjan, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Adaptation is key to minimizing heatwaves' societal burden; however, our understanding of adaptation capacity across the socioeconomic spectrum is incomplete. We demonstrate that observed heatwave trends in the past four decades were most pronounced in the lowest-quartile income region of the world resulting in >40% higher exposure from 2010 to 2019 compared to the highest-quartile income region. Lower-income regions have reduced adaptative capacity to warming, which compounds the impacts of higher heatwave exposure. We also show that individual contiguous heatwaves engulfed up to 2.5-fold larger areas in the recent decade (2010–2019) as compared to the 1980s. Widespread heatwaves can overwhelm …

Multiphysics Numerical Modeling Of Transient Transport Of Pfas, Pierrette Iradukunda, Arvin Farid

Civil Engineering Faculty Publications and Presentations

The need to understand the fate and transport of Per- and Polyfluoroalkyl substances (PFAS) has grown due to the widespread contamination of the environment by them. PFAS are persistent, mobile, toxic manmade chemicals of great concern that contribute to the contamination of soil and groundwater. The presence of PFAS in unsaturated soil complicates their transport due to the impact of the air–water interface and solid-phase adsorption. The air–water interface can significantly increase the retention of PFAS during its transport. In this paper, a numerical model has been developed to study the transport of PFAS by coupling transient seepage and advection-dispersion, …

Multi-Type Assessment Of Global Droughts And Teleconnections, Zahir Nikraftar, Abdorrahman Mostafaie, Mojtaba Sadegh, Javad Hatami Afkueieh, Biswajeet Pradhan

Civil Engineering Faculty Publications and Presentations

Several drought indices have been developed based on various processes (e.g., precipitation, soil moisture, vegetation health) that respond differently to modes of climate variability, shadowing their relatability to teleconnections, which in turn, limits drought forecasting. In this study, we advanced the multivariate analysis of droughts by using long-term Terrestrial Water Storage estimates, soil moisture and precipitation data along with normalized difference vegetation index. To this end, we employed a Vine copula approach using Archimedean and Elliptical copula families to generate two novel multivariate drought indices called Combined Standardized Drought Index (CSDI), based on agricultural, meteorological, hydrological and ecological univariate indices …

Double Averaging Analysis Applied To A Large Eddy Simulation Of Coupled Turbulent Overlying And Porewater Flow, Yan Ping Lian, Jonathan Dallman, Benjamin Sonin, Kevin R. Roche, Aaron I. Packman, Wing Kam Liu, Gregory J. Wagner

Civil Engineering Faculty Publications and Presentations

Freestream turbulence in rivers is a key contributor to the flux of dissolved nutrients, carbon, and other ecologically important solutes into porewater. To advance understanding of turbulent hyporheic exchange and porewater transport, we investigate flow over and through a rough bed of spheres using large eddy simulation (LES). We apply double averaging (combined space and time averaging) to the LES results to determine the mean velocity distribution, momentum balance, and drag forces. Our simulations show large-scale freestream structures interacting strongly with vortices generated at the surfaces of individual spheres to control turbulent momentum fluxes into the bed. The transition between …

Polar Ice As An Unconventional Water Resource: Opportunities And Challenges, Zahra Karimidastenaei, Björn Klöve, Mojtaba Sadegh, Ali Torabi Haghighi

Civil Engineering Faculty Publications and Presentations

Global water resources are under pressure due to increasing population and diminishing conventional water resources caused by global warming. Water scarcity is a daunting global problem which has prompted efforts to find unconventional resources as an appealing substitute for conventional water, particularly in arid and semiarid regions. Ice is one such unconventional water resource, which is available mainly in the Arctic and Antarctic. In this study, opportunities and challenges in iceberg utilization as a source of freshwater were investigated on the basis of a systematic literature review (SLR). A search in three databases (Scopus, Web of Science, and ProQuest) yielded …

Effects Of Air-Injection Pressure On Airflow Pattern Of Air Sparging, Arvin Farid, Atena Najafi, Jim Browning, Elisa Barney Smith

Civil Engineering Faculty Publications and Presentations

Air sparging is a remediation technology for treating soil/groundwater contaminated with volatile organic compounds (VOCs). VOC removal during air sparging is rendered less effective because of the random formation of air channels, creating preferential paths for airflow, thus limiting remediation to these channels, referred to as a zone of influence (ZOI). Pulsation is a popular method used to improve the effectiveness of air sparging through cyclic operation, with the hope that air channels would form elsewhere. Pulsation makes air sparging more time-consuming. This paper studies the effects of one cycle of pulsation and air pressure on the airflow pattern and …

Avoiding Water Bankruptcy In The Drought-Troubled Southwest: What The Us And Iran Can Learn From Each Other, Mojtaba Sadegh, Ali Mirchi, Amir Aghakouchak, Kaveh Madani

Civil Engineering Faculty Publications and Presentations

The 2021 water year ends on Sept. 30, and it was another hot, dry year in the western U.S., with almost the entire region in drought. Reservoirs vital for farms, communities and hydropower have fallen to dangerous lows.

The biggest blow came in August, when the U.S. government issued its first ever water shortage declaration for the Colorado River, triggering water use restrictions.

In response, farmers and cities across the Southwest are now finding new, often unsustainable ways to meet their future water needs. Las Vegas opened a lower-elevation tunnel to Lake Mead, a Colorado River reservoir where water levels …

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 …

Wip: Halting Attrition In Civil Engineering Programs Through Lower-Division Engagement Course Implementation, Briceland Mclaughlin, Nick Hudyma, Robert Hamilton, Bhaskar Chittoori, Mojtaba Sadegh, Sondra M. Miller

Civil Engineering Faculty Publications and Presentations

This work in progress paper will describe how a department of civil engineering has built 1-credit engagement courses into the first two years of a new curriculum design to increase retention rates, create a sense of belonging, showcase civil engineering principles and practicality to non-majors, and begin engaging alumni and local civil engineering professionals.

Retention is a core issue for academic departments in the STEM fields. In civil engineering, we have seen a large number of students depart the major each fall and spring semester for various, preventable reasons. This is true for traditional, non-traditional, and transfer students alike. Students …

A Practical Framework To Assess The Sustainability And Resiliency Of Civil Infrastructure, Thomas Adam Robbins, Bhaskar C. S. Chittoori

Civil Engineering Faculty Publications and Presentations

Research within civil engineering is focusing on newer ideas and philosophies such as sustainability and resiliency (S&R). This is evident in the development of frameworks for assessing the sustainability or the resiliency of civil infrastructures. Several frameworks have been developed by researchers to quantify the S&R of civil infrastructures. It is evident that the S&R are not mutually exclusive, and it is important to assess these aspects at the same time and that frameworks are able to accommodate simultaneous assessments. While there are other frameworks that follow a unified approach to S&R assessments, they do not account for the risk …

Anthropogenic Drought: Definition, Challenges, And Opportunities, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Traditional, mainstream definitions of drought describe it as deficit in water-related variables or water-dependent activities (e.g., precipitation, soil moisture, surface and groundwater storage, and irrigation) due to natural variabilities that are out of the control of local decision-makers. Here, we argue that within coupled human-water systems, drought must be defined and understood as a process as opposed to a product to help better frame and describe the complex and interrelated dynamics of both natural and human-induced changes that define anthropogenic drought as a compound multidimensional and multiscale phenomenon, governed by the combination of natural water variability, climate change, human decisions …

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 …

Environmental Geotechnics: Challenges And Opportunities In The Post-Covid-19 World, Arvin Farid

Civil Engineering Faculty Publications and Presentations

The outbreak of the coronavirus disease 2019 (Covid-19) pandemic not only has created a health crisis across the world but is also expected to impact negatively the global economy and societies at a scale that is maybe larger than that of the 2008 financial crisis. Simultaneously, it has inevitably exerted many negative consequences on the geoenvironment on which human beings depend. The current paper articulates the role of environmental geotechnics in elucidating and mitigating the effects of the current pandemic. It is the belief of all authors that the Covid-19 pandemic presents not only significant challenges but also opportunities for …

Compound Extremes Drive The Western Oregon Wildfires Of September 2020, John T. Abatzoglou, David E. Rupp, Larry W. O'Neill, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Several very large high‐impact fires burned nearly 4,000 km² of mesic forests in western Oregon during September 7–9, 2020. While infrequent, very large high‐severity fires have occurred historically in western Oregon, the extreme nature of this event warrants analyses of climate and meteorological drivers. A strong blocking pattern led to an intrusion of dry air and strong downslope east winds in the Oregon Cascades following a warm‐dry 60‐day period that promoted widespread fuel flammability. Viewed independently, both the downslope east winds and fuel dryness were extreme, but not unprecedented. However, the concurrence of these drivers resulted in compound extremes …

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 …