Browsing Earth and Environmental Systems by Title
Now showing items 30-33 of 33
Under the Influence of Large Woody Debris: A Survey of the La Crosse River In the Upper Midwest Driftless AreaStreams are dynamic environments driven by the force of gravity and shaped by local climate, geology, and vegetation. Large woody debris (LWD) can have important influences on stream processes. The main influence of LWD on these systems is a resistance to flow; this added roughness induces a multitude of channel adjustments. Despite the importance of LWD, streams have been heavily managed by humankind, often involving the removal of debris to improve flow. Recent studies have highlighted the significance of large woody debris in mountain streams, particularly in the Pacific Northwest of the United States and Canada. However, there has been little research on the influence of LWD on streams in the Upper Midwest. This study will specifically investigate a stream (the La Crosse River) in southwestern Wisconsin’s Driftless Area. This area remained untouched by glaciers during the Last Glacial Maximum, but outwash from melting glaciers was deposited here, making the main bed material coarse sand. Combining stream survey methods (channel cross-sections) and a wood census, the influence of LWD was determined through statistical analysis of measurements of stream (velocity, depth, and width) and LWD (total counts, length, DBH, and volume) characteristics, in conjunction with qualitative analysis of detailed cross-sections. LWD are present in the study reach, but few relationships proved statistically significant, while local influences (initiation of scour and deposition) are clearly seen. Explanations of human, regional, historical, and bed form influences are explored.
Urban Flash Flood Risk Assessment and Inundation Model Utilizing GIS for Terre Haute, IndianaUse of ArcGIS to examine flash flooding variables and produce a flash flood risk assessment and inundation model for Terre Haute, Indiana. Risk assessment, produced within ArcGIS, indicates that an increase in developed area leads to an increase in very high flash flood risk area and majority of very high risk area resides in developed areas of Terre Haute. Inundation model, produced using ArcGIS and Python, indicates that the proposed model can determine locations of flash flooding, but spatial extent of model predicted flooding is not reliable based on field validation.
Using Analogues to Simulate Intensity, Trajectory, and Dynamical Changes in Alberta Clippers with Global Climate ChangeAlberta Clippers are extratropical cyclones that form in the lee of the Canadian Rocky Mountains and traverse through the Great Plains and Midwest regions of the United States. With the imminent threat of global climate change and its effects on regional teleconnection patterns like El Niño-Southern Oscillation (ENSO), properties of Alberta Clipper could be altered as a result of changing atmospheric circulation patterns. Since the Great Plains and Midwest regions both support a large portion of the national population and agricultural activity, the effects of global climate change on Alberta Clippers could affect these areas in a variety of ways. Despite this reasoning, relatively few studies have addressed Alberta Clippers, especially in comparison to the other North American storm tracks. In this study, the effects of global climate change on Alberta Clippers are examined by using atmospheric analogues chosen from 1950-2012 based on temperature and ENSO characteristics. Composite maps of regional MSLP at 12-hr intervals, 300mb vector wind and geopotential height at the time of cyclogenesis, and 850mb temperature and geopotential height patterns 36 hours after Clipper formation are constructed. Difference maps of 300mb geopotential height patterns between each of the analogues are also constructed. One-way ANOVA tests are also used to analyze Alberta Clipper latitude and longitude values at t=0, Clipper trajectory azimuths from t=0 to t=60, central MSLP values for these storms twelve hours after formation, and MSLP pressure gradients at t=24. The results from these tests indicate that, of the four analogues, the Cold and El Niño years are the most dissimilar, maintaining statistically significant differences in upper-level wind magnitude and starting longitude values. MSLP at t=12 is lower in the Cold storms than the El Niño storms, but statistical significance between these values is not quite achieved. Furthermore, geopotential height differences and their associated rate of change with respect to map distance indicate that the 300mb geopotential height patterns of the El Niño and Cold analogues are quite different from one another. The La Niña and Warm analogue years are different from one another with respect to latitude and longitude values of Alberta Clippers at cyclogenesis. Based on these results, the effects of temperature increase alone will not influence the properties of Alberta Clippers as much as changes in ENSO that could be caused by global climate change.
USING THE SPATIAL VARIABILITY OF LEAD IN URBAN SOILS AND DEMOGRAPHIC VARIABLES TO PREDICT EXPOSURE RISKS: AN ENVIRONMENTAL JUSTICE ANALYSIS IN TERRE HAUTE, INDIANATerre Haute, Indiana, is similar to many older cities throughout the United States with a history of manufacturing and industry that relied on extensive road and rail networks. This industrial history has resulted in the presence of over 20 brownfields and even a Superfund Site within the city today. Historic neighborhoods and abundance of pre-1950’s homes is another characteristic of the city. Unfortunately, improper removal and deterioration of lead (Pb) paints, as well as high Pb solder used in gutters, appear to be significant sources of soil Pb in Terre Haute. Despite the fact that most new environmental sources of Pb pollution have been eradicated, many areas of the city still have elevated soil Pb concentrations and the city continues to have children with elevated blood Pb levels. With the Center for Disease Control’s recent reduction in screening levels for blood Pb from 10 μg/dL to 5 μg/dL, the occurrence of children with childhood Pb poisoning could be greater than previously recognized. The goal of this study was to better understand the modern-day spatial distribution of Pb in surface soils across the city of Terre Haute. To achieve this goal, surface soil samples were collected across the city. New data were collected from city-owned properties (i.e. parks, cemeteries, and abandoned lots), Indiana State University land holdings within the city, residential properties, and community gardens. Data collected from residential areas included samples near the road, from beneath the gutter dripline of the house, in the backyard, in the garden, and other areas of importance to the homeowner. Samples were analyzed via handheld X-ray fluorescence (XRF) analyzer on site to provide homeowner with immediate feedback with the ultimate goal of increasing the use of safer urban gardening practices. Samples were then dried and crushed to re-analyze with the portable XRF, and samples with values >200 ppm Pb were processed and analyzed with the ICP-OES to verify the results. Results produced a wide range of Pb concentrations, from <5 ppm to >30,000 ppm for the residential areas. The spatial distribution of Pb was determined using a simple ordinary kriging method and Empirical Bayesian Kriging method by analyzing the total sample set, samples collected near the road, samples from yards and gardens, and under the gutter driplines of homes were also kriged. Samples collected near the gutter dripline had the highest Pb concentrations, while overall spatial trends depict higher Pb concentrations in the historic portion of the city, with concentrations decreasing with distance from the older part of the city. The predicted Pb concentrations generated from the total sample set was then compared to demographic, environmental, and infrastructure characteristics for Terre Haute. OLS regressions using both maximum and average Pb concentrations indicate a statistically significant (p=0.000) positive correlation between high Pb concentrations and percentage of vacant homes. Maximum and average Pb concentrations were then linked to individual U.S. Census block groups with associated demographic attributes. Bivariate local indicator of spatial association (Bi-LISA) analysis indicates populations of low socio-economic status are regularly being exposed to higher Pb concentrations in their neighborhoods, while populations with higher socio-economic status are exposed to lower Pb concentrations. The higher Pb concentrations and populations with lower socio-economic status both occur in the central portion of the city where historic development occurred representing environmental injustice.