Engineering Commons^™

Wildfires Force Thousands To Evacuate Near Los Angeles: Here’S How The 2020 Western Fire Season Got So Extreme, Mojtaba Sadegh, Ata Akbari Asanjan, Mohammad Reza Alizadeh

Civil Engineering Faculty Publications and Presentations

Two wildfires erupted on the outskirts of cities near Los Angeles, forcing more than 100,000 people to evacuate their homes Monday as powerful Santa Ana winds swept the flames through dry grasses and brush. With strong winds and extremely low humidity, large parts of California were under red flag warnings.

High fire risk days have been common this year as the 2020 wildfire season shatters records across the West.

More than 4 million acres have burned in California – 4% of the state’s land area and more than double the previous annual record. Five of the state’s six largest historical …

Increasing Concurrence Of Wildfire Drivers Tripled Megafire Critical Danger Days In Southern California Between 1982 And 2018, Mohammad Sadegh Khorshidi, Philip E. Dennison, Mohammad Reza Nikoo, Amir Aghakouchak, Charles H. Luce, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Wildfire danger is often ascribed to increased temperature, decreased humidity, drier fuels, or higher wind speed. However, the concurrence of drivers—defined as climate, meteorological and biophysical factors that enable fire growth—is rarely tested for commonly used fire danger indices or climate change studies. Treating causal factors as independent additive influences can lead to inaccurate inferences about shifting hazards if the factors interact as a series of switches that collectively modulate fire growth. As evidence, we show that in Southern California very large fires and 'megafires' are more strongly associated with multiple drivers exceeding moderate thresholds concurrently, rather than direct relationships …

Changes In The Exposure Of California’S Levee-Protected Critical Infrastructure To Flooding Hazard In A Warming Climate, Iman Mallakpour, Mojtaba Sadegh, Amir Aghakouchak

Civil Engineering Faculty Publications and Presentations

Levee systems are an important part of California's water infrastructure, engineered to provide resilience against flooding and reduce flood losses. The growth in California is partly associated with costly infrastructure developments that led to population expansion in the levee protected areas. Therefore, potential changes in the flood hazard could have significant socioeconomic consequences over levee protected areas, especially in the face of a changing climate. In this study, we examine the possible impacts of a warming climate on flood hazard over levee protected land in California. We use gridded maximum daily runoff from global circulation models (GCMs) that represent a …

Decision-Support System For Lid Footprint Planning And Urban Runoff Mitigation In The Lower Rio Grande Valley Of South Texas, Javier Guerrero, Taufiqul Alam, Ahmed Mahmoud, Kim D. Jones, Andrew Ernest

Civil Engineering Faculty Publications and Presentations

To address regional flooding in the United States, federal and state agencies are adopting strict drainage policies in any large-scale commercial development within the watershed boundary. The conventional approach of implementing a wet detention pond (WP) reduces the land cover and causes operation and maintenance challenges eventually. The present study developed a decision-support system (DSS) in the Lower Rio Grande Valley region of South Texas for optimal selection of Best Management Practices (BMPs) by substituting a portion of the WP footprint with three regionally promising low-impact development practices, namely, porous concrete pavement (PCP), bioretention (BR), and bioswale (BS). Source Load …

Water Quality Improvement And Pollutant Removal By Two Regional Detention Facilities With Constructed Wetlands In South Texas, Javier Guerrero, Ahmed Mahmoud, Taufiqul Alam, Muhammed A. Chowdhury, Adeniyi Adetayo, Andrew Ernest, Kim D. Jones

Civil Engineering Faculty Publications and Presentations

Stormwater runoff introduces several pollutants to the receiving water bodies that may cause degradation of the water quality. Stormwater management systems such as detention facilities and wetland can improve the water quality by removing various pollutants associated with the runoff. The objective of this research project is to determine the performance and efficiency of two major regional detention facilities (RDFs) with different designs and structures in reducing pollutants based on various storm events in McAllen, Texas. The two sites are the McAuliffe RDF and the Morris RDF; each site was incorporated with a constructed wetland with a different design and …

Probabilistic Hazard Assessment Of Contaminated Sediment In Rivers, Shahab Aldin Shojaeezadeh, Mohammad Reza Nikoo, Ali Mirchi, Iman Mallakpour, Amir Aghakouchak, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

We propose a probabilistic framework rooted in multivariate and copula theory to assess heavy metal hazard associated with contaminated sediment in freshwater rivers that provide crucial ecosystem services such as municipal water source, eco-tourism, and agricultural irrigation. Exploiting the dependence structure between suspended sediment concentration (SSC) and different heavy metals, we estimate the hazard probability associated with each heavy metal at different SSC levels. We derive these relationships for warm (spring-summer) and cold (fall-winter) seasons, as well as stormflow condition, to unpack their nonlinear associations under different environmental conditions. To demonstrate its efficacy, we apply our proposed generic framework to …

Mitigation Localized Flooding - Development Of A Green Infrastructure Master Plan In The Lower Rio Grande Valley, Andrew Ernest, Javier Guerrero, Ahmed Mahmoud, Roxana Tello, Jose Figueroa, Jorge Hernandez

Civil Engineering Faculty Publications and Presentations

The City of Mercedes in partnership with the Lower Rio Grande Valley (LRGV) and The University of Texas Rio Grande Valley (UTRGV) proposed to develop a demonstration green infrastructure (GI) master plan to mitigate localized flooding in a high priority region within the city limits of the City. Local governments in the LRGV control localized flooding and stormwater runoff by adopting strict drainage design policies. During the course of this project, participating in local governments and the project team reviewed the city drainage policy. The project team identified those that already incorporate GI language, provided GI related information to the …