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Champaign, IL, United States

Angel J.R.,Illinois State Water Survey | Kunkel K.E.,Desert Research Institute
Journal of Great Lakes Research | Year: 2010

Future climate change and its impact on Lake Michigan is an important issue for water supply planning in Illinois. To estimate possible future levels of the Great Lakes due to climate change, the output of 565 model runs from 23 Global Climate Models were applied to a lake-level model developed by the Great Lakes Environmental Research Laboratory (GLERL). In this study, three future emission scenarios were considered: the B1, A1B, and A2 emission scenarios representing relatively low, moderate, and high emissions, respectively. The results showed that the A2 emission scenario yielded the largest changes in lake levels of the three emission scenarios. Of the three periods examined, lake levels in 2080-2094 exhibited the largest changes. The response of Lake Superior was the smallest of the Great Lakes, while lakes Michigan-Huron, Erie, and Ontario were similar in their response over time and between emission scenarios. For Lake Michigan-Huron, the median changes in lake levels at 2080-2094 were -0.25, -0.28, and -0.41 m for the B1, A1B, and A2 emission scenarios, respectively. However, the range in lake levels was considerable. The wide range of results is due to the differences in emission scenarios and the uncertainty in the model simulations. Selecting model simulations based on their historical performance does little to reduce the uncertainty. The wide range of lake-level changes found here make it difficult to envision the level of impacts that change in future lake levels would cause. © 2009 Elsevier B.V. Source

Verma S.,Urbana University | Markus M.,Illinois State Water Survey | Cooke R.A.,Urbana University
Journal of Hydrology | Year: 2012

This study used Monte Carlo sub-sampling and error-corrected statistical methods to estimate annual nitrate-N loads from two watersheds in central Illinois. The study objectives were (1) to evaluate the performance of various statistical load estimation methods for different combinations of monitoring durations and frequencies on nitrate-N load estimation accuracy, and (2) to develop and validate new empirical error correction techniques applied to the selected load estimation methods. We compared three load estimation methods (the 7-parameter regression estimator, the ratio estimator, and the flow-weighted average estimator) applied at 1, 2, 4, 6, and 8-week sampling frequencies and 1, 2, 3, and 6-year monitoring durations. Five error correction techniques; the existing composite method, and four new error correction techniques developed in this study; were applied to each combination of sampling frequency, monitoring duration and load estimation method. The newly proposed error correction techniques resulted in most accurate load estimates in 33 of 38 acceptable sampling combinations for both watersheds. On average, the most accurate error correction technique, (proportional rectangular) resulted in 15% and 30% more accurate load estimates when compared to the most accurate uncorrected load estimation method (ratio estimator) for the two watersheds. Using more accurate load estimation methods it is also possible to design more cost-effective monitoring plans by achieving the same load estimation accuracy with fewer observations. © 2012 Elsevier B.V. Source

Anderson B.T.,Boston University | Hayhoe K.,Texas Tech University | Liang X.-Z.,Illinois State Water Survey
Climatic Change | Year: 2010

Potential changes in summertime hydroclimatology over the northeastern (NE) region of the USA induced by increases in greenhouse gas (GHG) concentrations are investigated using a state-of-the-art regional climate modeling system. Results for a higher emissions scenario illustrate changes that may occur if dependence on fossil fuels continues over the coming century. Summertime precipitation is projected to decrease across much of the central NE, but increase over the southernmost and northernmost portions of the domain. Evaporation is expected to increase across the entire domain. The balance between these two results in a decrease in soil moisture content across most of the domain (by approximately 10 mm) and an increase in the summertime soil-moisture depletion rate (by approximately 10 mm/month). At the same time, an increase in both atmospheric near-surface specific and saturation specific humidity is projected, resulting in an increase in relative humidity across the southern portion of the domain, with slight decreases over the northern portion. Combined with an average increase in summer temperatures of 3. 5°C, the projected increase in relative humidity results in a marked increase in the average daily maximum heat index for the region on the order of 3. 9°C, as well as a 350-400% increase in the number of days with heat index values exceeding 32. 2°C (90°F)-the level of "extreme caution". Taken together, these high-resolution, dynamically-generated projections confirm the potential for significant summertime climate change impacts on the NE over the coming century as suggested by previous studies. © Springer Science+Business Media B.V. 2009. Source

Zhou Q.,Lawrence Berkeley National Laboratory | Birkholzer J.T.,Lawrence Berkeley National Laboratory | Mehnert E.,Illinois State Geological Survey | Lin Y.,Illinois State Water Survey | Zhang K.,Lawrence Berkeley National Laboratory
Ground Water | Year: 2010

Integrated modeling of basin- and plume-scale processes induced by full-scale deployment of CO2 storage was applied to the Mt. Simon Aquifer in the Illinois Basin. A three-dimensional mesh was generated with local refinement around 20 injection sites, with approximately 30 km spacing. A total annual injection rate of 100 Mt CO2 over 50 years was used. The CO2-brine flow at the plume scale and the single-phase flow at the basin scale were simulated. Simulation results show the overall shape of a CO2 plume consisting of a typical gravity-override subplume in the bottom injection zone of high injectivity and a pyramid-shaped subplume in the overlying multilayered Mt. Simon, indicating the important role of a secondary seal with relatively low-permeability and high-entry capillary pressure. The secondary-seal effect is manifested by retarded upward CO2 migration as a result of multiple secondary seals, coupled with lateral preferential CO2 viscous fingering through high-permeability layers. The plume width varies from 9.0 to 13.5 km at 200 years, indicating the slow CO2 migration and no plume interference between storage sites. On the basin scale, pressure perturbations propagate quickly away from injection centers, interfere after less than 1 year, and eventually reach basin margins. The simulated pressure buildup of 35 bar in the injection area is not expected to affect caprock geomechanical integrity. Moderate pressure buildup is observed in Mt. Simon in northern Illinois. However, its impact on groundwater resources is less than the hydraulic drawdown induced by long-term extensive pumping from overlying freshwater aquifers. Copyright © 2009 The Author(s). Journal compilation © 2009 National Ground Water Association. Source

Changnon S.A.,Illinois State Water Survey
Natural Hazards | Year: 2011

High winds are one of the nation's leading damage-producing storm conditions. They do not include winds from tornadoes, winter storms, nor hurricanes, but are strong winds generated by deep low pressure centers, by thunderstorms, or by air flow over mountain ranges. The annual average property and crop losses in the United States from windstorms are $379 million and windstorms during 1959-1997 caused an average of 11 deaths each year. Windstorms range in size from a few hundred to hundreds of thousands square kilometers, being largest in the western United States where 40% of all storms exceed 135,000 km2. In the eastern United States, windstorms occur at a given location, on average, 1.4 times a year, whereas in the western US point averages are 1.9. Midwestern states average between 15 and 20 wind storms annually; states in the east average between 10 and 25 storms per year; and West Coast states average 27-30 storms annually. Storms causing insured property losses >$1 million, labeled catastrophes, during 1952-2006 totaled 176, an annual average of 3.2. Catastrophic windstorm losses were highest in the West and Northwest climate regions, the only form of severe weather in the United States with maximum losses on the West Coast. Most western storms occurred in the winter, a result of Pacific lows, and California has had 31 windstorm catastrophes, more than any other state. The national temporal distribution of catastrophic windstorms during 1952-2006 has a flat trend, but their losses display a distinct upward trend with time, peaking during 1996-2006. © 2011 Springer Science+Business Media B.V. Source

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