The effects of future extreme precipitation events on stream hydrology and hydraulics of stream crossing structures

Army field training exercises are conducted to replicate real-world combat requirements and are inherently subject to the effects of the prevailing climate and weather conditions. Adapting to variability of climate is part of realistic training and extreme storm events and associated flooding risks can temporarily limit access to training lands and other training features such as water crossings. If an increase in intensity and incidence of extreme precipitation events is realized, installations associated with river systems are likely to have increased flood risk and associated prevention and mitigation costs. Low water crossings (LWCs) are especially susceptible to changes in intensity and incidence of extreme precipitation events with regards to infrastructure usability, resilience, and safety. The June 2, 2016 incident at Fort Hood, TX where five soldiers from the 3rd Battalion, 16th Field Artillery Regiment, 2nd Armored Brigade Combat Team, 1st Cavalry Division drowned when their troop carrier overturned at a flooded LWC, shows the safety risks associated with LWCs. The first objective of this study is to examine the stationary assumption of total annual precipitation, total annual wet days and wet hours, and regional frequency analysis for a range of design storms and extreme events. Both parametric and non-parametric statistical tests were used to detect trends. In addition, precipitation frequency estimates were calculated for the 0.5-, 1-, 2-, 5-, 10-, 25-, 50-, and 100-year Annual Return Interval (ARIs) and durations of 1-, 2-, 3-, 6-, 12-, and 24-hr; and 2-, 5-, and 10-days for three different time periods 1970-1989, 1980-1999, and 1990-2009. The results suggest the assumption that precipitation is stationary over time with regards to total annual rainfall and storm frequency is not valid for the three Midwest regions, Central Indiana, East Central Illinois, and Central Michigan. The second objective is to analyze projected precipitation data from four climate models with regards to total annual precipitation, total annual wet days and wet hours, and regional frequency analysis for a range of design storms and extreme events and compare findings to analyses of historic precipitation data. Four dynamically downscaled CMIP5 global climate models were bias corrected using quantile mapping. The average projected (2080-2099) design storm of the four climate models across all locations, durations, and return periods is larger than the corresponding observed design storm and usually significantly larger based on the standard deviation of the model results, especially for return periods greater than 1 year. The four models provided bias-corrected precipitation output that agreed in general trends, however, the precise levels of precipitation increases varied substantially, especially for the 2040-2059 projected timeframe. The third objective is to apply projected climate model precipitation to hydrologic models to determine projected stream flow characteristics and compare to current stream flow characteristics. The result indicate increases in peak flood events across all return periods for the projected timeframes compared to observed conditions. In Indiana and Michigan the projected (2080-2099) peak flow events are larger than the projected (2040-2059) peak flows while in Illinois the projected (2080-2099) peak flow events are larger than or equal to the former events. Analysis of the number of days projected stream flow exceeds the 0.5-, 1-, and 10-yr design flows during the 20-yr simulation showed a wide range of results between the two models representing the upper and lower bounds of maximum precipitation estimates for a majority of return periods for each projected timeframe at each location. Generally there was an increase in exceedances during the projected timeframes compared to current conditions, but on a yearly average basis the increase were minimal. The fourth objective is to route projected design flow and continuous stream flow hydrographs through hydraulic models to determine usability and sustainability of current structures and feasibility of alternative designs for projected flow regimes. The results indicate the riverine crossing structures considered for this study are projected to see an increase in the magnitude and frequency of high flow events by the end of this century. The projected (2080-2099) 10-yr event is on the order of the present 50-yr (sometimes 25-yr or 100-yr) event for many of the studied streams, suggesting possible future conditions should be considered when designing new infrastructure. Unfortunately the uncertainty inherent in the climate modeling makes it difficult to develop specific recommendations on how to revise current LWC design criteria with regards to climate change in the study regions. The continuous model simulations and projections proved to underestimate average yearly flow durations for small flow events with very frequent return periods. Special care must be taken when using and applying frequent events from dynamically downscaled climate model precipitation data. An investigation into the timing and intensity of very frequent observed and simulated precipitation events could be needed before applying similar climate model data to hydrologic and hydraulic models. Overall, they study showed that the riverine crossing structures considered for this study are projected to see an increase in the magnitude and frequency of high flow events by the end of this century. The changes in hydrologic flows were constant with changes in projected precipitation. The four climate models provided bias-corrected precipitation output that agreed in general trends but the precise levels of precipitation increases varied substantially, especially for the 2040-2059 projected timeframe. In addition, watershed specific variables, such as those found in Michigan, can add a great deal of uncertainty to modeling results. The projected increases in precipitation and subsequent changes in peak flood events are large enough that corresponding impacts on stormwater infrastructure design should be considered, however, the uncertainty of the future projections makes it difficult to develop specific design recommendations

Report for the Urban Flooding Awareness Act

Illinois General AssemblyOpe

The Experiment for Space Radiation Analysis: Probing the Earth\u27s Radiation Belts Using a CubeSat Platform

The Experiment for Space Radiation Analysis (ESRA) is the latest of a series of Demonstration and Validation missions built by the Los Alamos National Laboratory, with the focus on testing a new generation of plasma and energetic particle sensors. The primary motivation for the ESRA payloads is to minimize size, weight, power, and cost while still providing necessary mission data. These new instruments will be demonstrated by ESRA through testing and on-orbit operations to increase their technology readiness level such that they can support the evolution of technology and mission objectives. This project will leverage a commercial off-the-shelf CubeSat avionics bus and commercial satellite ground networks to reduce the cost and timeline associated with traditional DemVal missions. The system will launch as a ride share with the DoD Space Test Program to be inserted in Geosynchronous Transfer Orbit (GTO) and allow observations of the Earth’s radiation belts. The ESRA CubeSat consists of two science payloads and several subsystems: the Wide-field-of-view Plasma Spectrometer, the Energetic Charged Particle telescope, high voltage power supply, payload processor, flight software architecture, and distributed processor module. The ESRA CubeSat will provide measurements of the plasma and energetic charged particle populations in the GTO environment for ions ranging from ~100 eV to ~1000 MeV and electrons with energy ranging from 100 keV to 20 MeV. ESRA will utilize a commercial 12U bus and demonstrate a low-cost, rapidly deployable spaceflight platform with sufficient SWAP to enable efficient measurements of the energetic particle populations in the dynamic radiation belts

Development of Low-Water Crossing Design Guidelines for Very Low ADT Routes in Illinois

The Illinois Department of Transportation (IDOT) and local agencies monitor and regulates the 146,764 mi of roadway that are open to public travel in the State of Illinois. There are many old and aging bridges, culverts, and low-water crossings on rural low-volume roads that need to be replaced. Low-water crossings (LWCs) have been used as an economical alternative to culverts and bridges, designed without overtopping, on low-volume roads where there is low number of floods. The lack of design guidance has posed difficulty for county engineers in Illinois in deciding when, where, and which type of low-water crossing to use. The resulting structure is often either overdesigned or underdesigned. A study was conducted to design the guidelines for LWCs in Illinois at the University of Illinois at Urbana-Champaign in collaboration with the U.S. Army Corps of Engineers - Construction Engineering Research Laboratory (CERL) and support from the IDOT. The study included literature review, a LWC survey, and case studies on LWCs in Illinois. The results from a survey conducted among the county engineers in Illinois about their experience with LWCs are presented, along with commonly used LWCs, site considerations, selection criteria, and signage requirements. Design criteria and procedure for the LWCs design, construction, and best management practices are also discussed. Additionally, case studies, design examples, and permitting requirements for LWCs are included in the report. Implementation of LWC guidelines could save local agencies significant funding, due to lower construction and maintenance costs, less channel and flood plain blockage, and better adaptability and storm-proofing characteristics, as well as reduced impacts to aquatic organism passage.Illinois Department of Transportation, R27-148Ope

Reduced Axial Scan Length Coronary Calcium Scoring Reduces Radiation Dose and Provides Adequate Clinical Decision-Making Before Coronary CT Angiography

Extensive coronary artery calcium (CAC) diminishes the accuracy of coronary computed tomography angiography (CCTA). Many imagers adjust CCTA acquisition parameters depending on a preCCTA Agatston CAC score to optimize diagnostic accuracy. Typical preCCTA CAC imaging adds considerably to radiation exposure, partially attributable to imaging beyond the area known for highest CAC, the proximal coronary arteries. We aimed to determine whether a z-axis reduced scan length (RSL) would identify the majority of CAC and provide adequate information to computed tomography angiography providers relative to a standard full-scan length (FSL) preCCTA noncontrast CT. We retrospectively examined 200 subjects. The mean CAC scores detected in RSL and FSL were 77.4 (95% CI 50.6 to 104.3) and 93.9 (95% CI 57.3 to 130.5), respectively. RSL detected 81% of the FSL CAC. Among false negatives, with no CAC detected in RSL, FSL CAC severity was minimal (mean score 2.8). There was high concordance, averaging 88%, between CCTA imaging parameter adjustment decisions made by 2 experienced imagers based on either RSL or FSL. CAC detected and decision concordance decreased with increasing CAC burden. CAC detected was lower, and false negatives were more common in the right coronary artery owing to its anatomic course, placing larger segments outside RSL. Axial scan length and effective dose decreased 59% from FSL (∼14.5 cm/∼1.1 mSv) to RSL (∼5.9 cm/∼0.45 mSv). This retrospective study suggests that RSL identifies most CAC, results in similar CCTA acquisition parameter modifications, and reduces radiation exposure. Our colleagues corroborated these results in a recently published prospective study