Elevated Risk of Compound Extreme Precipitation Preceded by Extreme Heat Events in the Upper Midwestern United States

Compound extreme events can potentially cause deadlier socio-economic consequences. Although several studies focused on individual extreme climate events, the occurrence of compound extreme events is still not well studied in the upper Midwestern United States. In this study, compound extreme precipitation preceded by extreme hot day events was investigated. Results showed a strong linkage between extreme precipitation events and extreme hot days. A significant increasing trend was noticed mainly in Iowa (10.1%), northern parts of Illinois (5.04%), and Michigan (5.04%). Results also showed a higher intensity of extreme precipitation events preceded by an extremely hot day compared to the intensity of extreme precipitation events not preceded by an extremely hot day, mostly in the central and lower parts of Minnesota, western and upper parts of Iowa, lower and upper parts of Illinois, parts of Ohio, Michigan, and Wisconsin for 1950–2010. In other words, extreme heat contributed to more extreme precipitation events. Our findings would provide important insights related to flood management under future climate change scenarios in the region

Combining Environmental Monitoring and Remote Sensing Technologies to Evaluate Cropping System Nitrogen Dynamics at the Field-Scale

Nitrogen (N) losses from cropping systems in the U.S. Midwest represent a major environmental and economic concern, negatively impacting water and air quality. While considerable research has investigated processes and controls of N losses in this region, significant knowledge gaps still exist, particularly related to the temporal and spatial variability of crop N uptake and environmental losses at the field-scale. The objectives of this study were (i) to describe the unique application of environmental monitoring and remote sensing technologies to quantify and evaluate relationships between artificial subsurface drainage nitrate (NO3-N) losses, soil nitrous oxide (N2O) emissions, soil N concentrations, corn (Zea mays L.) yield, and remote sensing vegetation indices, and (ii) to discuss the benefits and limitations of using recent developments in technology to monitor cropping system N dynamics at field-scale. Preliminary results showed important insights regarding temporal (when N losses primarily occurred) and spatial (measurement footprint) considerations when trying to link N2O and NO3-N leaching losses within a single study to assess relationship between crop productivity and environmental N losses. Remote sensing vegetation indices were significantly correlated with N2O emissions, indicating that new technologies (e.g., unmanned aerial vehicle platform) could represent an integrative tool for linking sustainability outcomes with improved agronomic efficiencies, with lower vegetation index values associated with poor crop performance and higher N2O emissions. However, the potential for unmanned aerial vehicle to evaluate water quality appears much more limited because NO3-N losses happened prior to early-season crop growth and image collection. Building on this work, we encourage future research to test the usefulness of remote sensing technologies for monitoring environmental quality, with the goal of providing timely and accurate information to enhance the efficiency and sustainability of food production

Modeling fate and transport of Cryptosporidium parvum and rotavirus in overland flow

In the United States, there have been at least 1870 outbreaks associated with drinking water during the period of 1920 to 2002, causing 883,806 illnesses. Most of these outbreaks are resulted due to the presence of microbial pathogens in drinking water. Cryptosporidium parvum (C. parvum) has been recognized as one of the most frequently occurring microbial contaminants that can cause infection and diarrhea in many mammalian hosts, including humans. About 403,000 of an estimated 1.61 million residents in the Milwaukee area became ill with the stomach cramps, fever, diarrhea and dehydration caused by the outbreak of C. parvum in 1993. It was the largest waterborne disease outbreak in documented United States history. Similarly, rotavirus is the leading cause of death among children around the world. Each year more than two million children are hospitalized due to rotavirus infection and more than 500,000 children die from diarrheal disease caused by rotavirus. Past studies have demonstrated that environmental factors such as rainfall intensity and duration, slope, soil type and surface cover conditions significantly affect the transport of C. parvum oocyst and rotavirus in surface flow. Laboratory experiments conducted at the University of Illinois have demonstrated C. parvum oocysts and rotavirus transport is greatly influenced by climatic and soil-surface conditions like slope, soil types, soil texture, and ground cover. The objective of this study was to simulate the fate and transport of C. parvum and rotavirus in overland flow in different ground cover and slope conditions. Transport of pathogens in overland flow can be simulated mathematically by including terms for the concentration of the pathogens in the liquid phase (in suspension or free-floating) and the solid phase (adsorbed to the soil solid particles like clay, sand and silt). Advection, adsorption, and decay processes have been considered in the physically-based model. The mass balance equations have been solved using numerical technique to predict spatial and temporal changes in pathogen concentrations in two phases. In order to capture the dynamics of sediment-bound pathogen, the Water Erosion Prediction Project (WEPP) is coupled with the pathogen transport model. Outputs from WEPP simulations (flow velocity, depth, saturated conductivity and the soil particle fraction exiting in flow) are transferred as input to the pathogen transport model. Altogether four soil types (Alvin, Catlin, Darwin and Newberry), four slope conditions (1.5, 2.5, 3.0 and 4.5%), three rainfall intensities (2.54, 6.35 and 9.0 cm/hr), and three different surface cover conditions (bare, Brome grass and Fescue) have been used in the experimental investigations. Results of C. parvum and rotavirus transport from these conditions have been used in calibrating and validating the model simulation results. Model simulation results of C. parvum and rotavirus transport through soil surface with and without any ground cover (bare soil) have produced very good agreement between observed and predicted results in most cases. Experimental data on pathogen transport showed multiple peaks in few cases. It was noted that the model results could capture only first observed peak in pathogen break through curve but could not replicate multiple peaks in pathogen transport that were found in experimental results. Additionally, there were more parameters used in model calibration for vegetated surface compared to surface without ground cover. This study provides both success and challenges of the Cryptosporidium parvum and rotavirus modeling and list future activities so that a pathogen transport model can be reasonably used under different climatic and soil conditions

The Efficiency of a Pyramid-shaped Solar Still

Clean water is essential for human life. The availability of clean water affects people worldwide. A large number of people without direct access to clean drinking water live within close proximity of an ocean, and therefore have direct access to saltwater. A low-cost, sustainable method for removing the salt from the water would have huge benefits for these people. Different types of desalination models have recently been developed to remove salt and purify the water. However, these models either have a very low yield of purified water or are cost prohibitive for most people in poor regions of the world. The objective of this study was to create a cost-efficient solar-still desalination model that can be used anywhere in the world, especially in developing countries that currently lack the infrastructure and resources to provide clean water to residents. The system designed in this study was able to effectively evaporate water in the first step of the purification process. However, only preliminary results were obtained due to time limitation and the need to make design modifications to improve the collection of the evaporated water.Ope

The Efficiency of a Trapezoid-shaped Solar Still

Drinking water is scarce in developing countries and is becoming a limiting resource for the entire world. This experiment focuses on the enhancement of a solar purification model known as a solar still. The improvement of the solar still will make purifying water a viable option in poor areas of the world and the solar still will reduce the amount of water purified using petroleum-based energy sources and help temper the ongoing water crisis. A solar still model with a polyethylene top and a mirror inside was tested for three hours on three different days and the purified water measured. The model barely yielded results, with only one of the three days producing a measurable amount of water. While the tests yielded very little purified water, the model did evaporate a significant amount of water, which could mean that by fixing a small design flaw, this system could be a solution to water scarcity on islands and other areas with limited access to fresh, clean drinking water.Ope

Blood Flow Simulation through a Rat's Aortic Arch

Rat models are used to examine the blood flow in a setting similar to that of humans. For this research, we are interested in creating a working model which we can use to further investigate aortic malfunction for the purpose of improving blood flow in patients with blood vessel disorder. Initially, we designed the working model of a rat aortic arch with adequate geometry using Solidworks. We defined the proper boundary conditions to perform blood flow simulations on the aortic arch. For inlet boundary, we took velocity information of a lab rat, obtained using Doppler velocimetry. This data was then imported into Matlab to generate a function expression using a curve fitting tool. For the outlet, because the pressure boundary conditions are a priori unknown, we simulated the model with different gage pressure within realistic bounds to test their effect. We applied zero gage pressure at the bottom outlets, and zero, 5 mm Hg and 20 mm Hg gage pressure at top outlets to test our model using three cases. The model was imported into Comsol Multiphysics to perform the various transient simulations. We found that the flow is relatively robust to the unknown outlet pressure. We were also able to measure the pressure stress on the aorta, which is crucial for future study on aortic rigidity.Mechanical Engineering, Department ofHonors Colleg

Low-Water Crossings: An Overview of Designs Implemented along Rural, Low-Volume Roads

Replacement of many old and aging bridges, culverts, and low-water crossings on rural low-volume roads is an increasing concern throughout the United States. The economic burden for many local bodies can be huge if these structures are to be replaced by a bridge or culvert. A low-water crossing (LWC) is a feasible and efficient road-stream crossing structure that can be used on these roads as an economical alternative to culverts and bridges. Three types of commonly used LWCs; unvented fords, vented fords and low-water bridges; their selection criteria, environmental considerations, design process, materials selection, signage and permitting requirements are included in this paper. Some of the issues with the existing LWCs are the safety in the crossing and effects on aquatic organism passage and surrounding environment. Through proper design, construction, and installation of proper signage, the functionality and reliability of LWCs can be improved. The study provides engineers and other practitioners in the United States and elsewhere with a proper set of information and design procedures for using LWCs

Evaluation of Various Perimeter Barrier Products

Construction activities entail substantial disturbance of topsoil and vegetative cover. As a result, stormwater runoff and erosion rates are increased significantly. If the soil erosion and subsequently generated sediment are not contained within the site, they would have a negative off-site impact as well as a detrimental influence on the receiving water body. In this study, replicable large-scale tests were used to analyze the ability of products to prevent sediment from exiting the perimeter of a site via sheet flow. The goal of these tests was to compare products to examine how well they retain sediment and how much ponding occurs upstream, as well as other criteria of interest to the Illinois Department of Transportation. The products analyzed were silt fence, woven monofilament geotextile, Filtrexx Siltsoxx, ERTEC ProWattle, triangular silt dike, sediment log, coconut coir log, Siltworm, GeoRidge, straw wattles, and Terra-Tube. Joint tests and vegetated buffer strip tests were also conducted. The duration of each test was 30 minutes, and 116 pounds of clay-loam soil were mixed with water in a 300 gallon tank. The solution was continuously mixed throughout the test. The sediment-water slurry was uniformly discharged over an 8 ft by 20 ft impervious 3:1 slope. The bottom of the slope had a permeable zone (8 ft by 8 ft) constructed from the same soil used in the mixing. The product was installed near the center of this zone. Water samples were collected at 5 minute intervals upstream and downstream of the product. These samples were analyzed for total sediment concentration to determine the effectiveness of each product. The performance of each product was evaluated in terms of sediment removal, ponding, ease of installation, and sustainability.IDOT-ICT-190Ope

Analysis of Best Management Practices Implementation on Water Quality Using the Soil and Water Assessment Tool

The formation of hypoxic zone in the Gulf of Mexico can be traced to agricultural watersheds in the Midwestern United States that are artificially drained in order to make the land suitable for agriculture. A number of best management practices (BMPs) have been introduced to improve the water quality in the region but their relative effectivenss of these BMPs in reducing nutrient load has not been properly quantified. In order to determine the BMPs useful for reducing nutrient discharge from a tile drained watershed, a Soil and Water Assessment Tool (SWAT) model was calibrated and validated for water flow and nitrate load using experimental data from the Little Vermillion River (LVR) watershed in east-central Illinois. Then, the performance of four common BMPs (reduced tillage, cover crop, filter strip and wetlands) were evaluated. For BMPs, the usage of rye as cover crop performed the best in reducing nitrate discharge from the watershed as a single BMP, with an average annual nitrate load reduction of 54.5%. Combining no tillage and rye cover crops had varying results over the period simulated, but the average nitrate reduction was better than using rye cover crops with conventional tillage, with the average annual nitrate discharge decreased by 60.5% (an improvement of 13% over rye only)