Organization | • | Illinois State Water Survey | [X] |
| | 81: | | Title: | | | | | Volume/Number: | 2002 | | | | Issuing Agency: | | | | | Description: | Sedimentation detracts from the use of any water-supply lake by reducing lake depth and volume, with a reduction of reserve water-supply capacity and possible burying of intake structures. Sedimentation of a reservoir is a natural process that can be accelerated or slowed by human activities in the watershed. Lake Decatur is located in Macon County, northeast of Decatur, Illinois. The location of the dam is 39 49' 28' north latitude and 88 57' 30' west longitude in Section 22, T.16N., R.2W., Macon County, Illinois. The dam impounds the Sangamon River in the Sangamon River basin. The watershed is a portion of Hydrologic Unit 07130006 as defined by the U.S. Geological Survey. The lake was constructed in 1922 with a spillway level of 610 feet above mean sea level (feet-msl). In 1956, a set of hydraulic gates was installed on the original spillway to allow variable lake levels from 610 feet-msl to 615 feet-msl. The portions of the lake surveyed for the present study were the Big and Sand Creek basins. These basins are the two major tributary stream basins formed to the south (Sand Creek) and east (Big Creek) of the main body of the lake. They receive the flow of Sand, Big, and Long Creeks. Lake Decatur has been surveyed to document sedimentation conditions nine times since 1930. Five of these survey efforts (1936, 1946, 1956, 1966, and 1983) were sufficiently detailed to be termed full lake sedimentation surveys. The survey discussed in detail in this report is not a full lake sedimentation survey. However, additional work included in the present study could be combined with the 2000 survey of Basin 6 of Lake Decatur to provide a complete baseline survey for future reference. Sedimentation has reduced Big Creek basin capacity from 2,754 acre-feet (ac-ft) in 1922 to 1,512 ac-ft in 2001. The 2001 basin capacity was 54.9 percent of the 1922 potential basin capacity. For water-supply purposes, these volumes convert to capacities of 897 million gallons in 1922 and 493 million gallons in 2001. Sedimentation rate analyses indicate a decline in annual sediment deposition rates from 28 ac-ft (1922-1946) to 9.9 ac-ft annually (1983-2001). The long-term average annual deposition rate was 15.7 ac-ft (1922-2001). Sedimentation has reduced the Sand Creek basin capacity from 610 acre-feet (ac-ft) in 1922 to 246 ac-ft in 2001. The 2001 basin capacity was 40.3 percent of the 1922 potential basin capacity. For water-supply purposes, these volumes convert to capacities of 199 million gallons in 1922 and 80 million gallons in 2001. Sedimentation rate analyses indicate a decline in annual sediment deposition rates from 8.4 ac-ft (1922-1946) to 2.3 ac-ft annually (1983-2001). The long-term average annual deposition rate was 4.6 ac-ft (1922-2001). | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2002-09 | | | | ISL ID: | 000000000870 Original UID: 999999994347 FIRST WORD: Sedimentation | |
| 82: | | Title: | | | | | Volume/Number: | 2002 | | | | Issuing Agency: | | | | | Description: | The hydrologic regime of a natural stream is usually highly complex and encompasses a wide range of discharges. The magnitudes and frequencies at which the various discharges occur play a key role in creating the channel's morphology. The concept of 'dominant discharge' proposes that there exists a single steady discharge that, theoretically, if constantly maintained in a stream over a long period of time would form and maintain the same basic stable channel dimensions as those produced by the long-term natural hydrograph. This theoretical discharge is referred to as a stream's dominant discharge. If such a dominant discharge exists and can be accurately calculated, this discharge can be one of the tools that stream restoration personnel use to help design channels that are morphologically stable, i.e., not experiencing either excessive erosion or sediment deposition. There is no direct method to calculate a stream's dominant discharge, and stream researchers have commonly assumed that the dominant discharge can be equated with either the stream's bankfull discharge, a specific flood recurrence interval, or the stream's effective discharge. The purpose of this study is to analyze the available data and existing computational methods for the third approach, that being the estimation of effective discharges specific to Illinois streams. The effective discharge of a stream is defined as the single discharge rate that carries the most sediment over time. Note that the effective discharge is not typically a discharge associated with the most extreme flood events, which may carry large amounts of sediment load but occur infrequently. Instead it is commonly considered to be a moderately high discharge having a more modest load, but occurring frequently enough that in the long-run it carries more sediment than the extreme flood events. To facilitate computations, the effective discharge is estimated as occurring within a discharge class or increment, rather than as a single discharge. Effective discharge can be estimated using data on suspended sediment load, bed load, bed material, or total sediment load, with the method of estimation depending on the sediment transport characteristics of the stream, available data, and, to some degree, the researcher's school of thought. For this study, estimates of effective discharges are based on the suspended sediment load, which is the dominant load in most Illinois streams. Suspended sediment data collected at 88 gaging stations within Illinois were analyzed to determine which gaging stations in Illinois currently have sufficient suspended sediment data available to estimate effective discharges. A procedure was adapted from previous research and implemented to compute effective discharge values for each stream location having sufficient suspended sediment data. For each of those gaging stations, an estimate was made of the flow frequency at which the effective discharge was equaled or exceeded. For stations having adequate sediment data, flood recurrence intervals associated with effective discharge values were computed using annual maximum flow data. Correlation coefficients (r2) for 12 linear regressions are presented to describe the relationship between six effective discharge parameters and channel slope and watershed area. The data from 20 of the 88 gaging stations were deemed sufficient for computing effective discharge values. These 20 gaging stations were located on streams with watershed areas ranging from 244 to 6363 square miles (mi2). The relatively large watershed areas allow use of mean daily discharge values in computing effective discharge values. The annual maximum series analysis indicated that recurrence intervals associated with effective discharges found at these stations ranged from less than 1.01 years to 1.23 years. Such recurrence intervals are on the low end of the 1- to 3-year recurrence intervals commonly reported in other studies. However, these recurrence intervals are representative of Illinois' larger watersheds, and recurrence intervals of effective discharges in smaller Illinois watersheds could be quite different. Of the 20 qualified stations, 20 percent had effective discharge estimates that were less than the station's average mean daily discharge. Such low magnitude flow events are not usually associated with a stream's dominant discharge. Thus, geomorphic assessments and bankfull computations are required to further assess whether these and other effective discharge values are representative of the 20 individual streams' dominant discharges. Due to the small sample size, regression analyses relating specific effective discharge parameters to channel slope and watershed area were inconclusive. Effective discharge computations are particularly sensitive to how the sediment rating curve used in the computation is developed and the number of discharge classes used in the computation. The sampling frequency and duration over which the sediment samples used to create sediment rating curves also may influence effective discharge computations significantly. Thus, while stream restoration personnel will likely continue to use these and other effective discharge values as part of several tools in hydraulic and channel design applications, uncertainties in their use should be acknowledged and undue weight should not be assigned these values, as they cannot yet be expected to yield fully reliable results in applications. Like previous researchers, we recommend more comprehensive investigations that compare effective discharge estimates to bankfull discharges in combination with a geomorphic assessment of each stream's characteristics to yield a better understanding of whether currently computed effective discharge values adequately represent dominant discharges in Illinois. Suspended sediment represents the dominant sediment load in most Illinois streams. In some cases, effective discharge computations based on total loads or bed material loads may be more appropriate than using suspended sediment loads analyzed here. However, the bed load, bed material, bank material, local channel slope, and channel cross-section information required to perform these computations and analyses are almost nonexistent. While many of these data can be collected at selected stream locations, inherent difficulties in estimating bed loads in Illinois streams make this approach unfeasible. New technologies for sampling or estimating bed load most likely would need to be developed and tested. This analysis presents a comprehensive assessment of effective discharges based on the available suspended sediment and flow data in Illinois. Long-term sediment data sets are needed at more stream locations to more fully estimate and understand effective and dominant discharges in Illinois streams. The greatest need for additional data is for smaller watersheds less than approximately 200 mi2 because most potential applications of the effective discharge concept in stable channel design are for smaller watersheds. Smaller watersheds also may have significantly different geomorphic characteristics and effective discharges may behave differently than those in larger watersheds. The Illinois State Water Survey currently is measuring suspended sediment at gaging stations on 13 small watersheds, which could prove very useful in effective discharge analysis as longer data records become available at these sites. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2002-10 | | | | ISL ID: | 000000000871 Original UID: 999999994348 FIRST WORD: Effective | |
| 83: | | Title: | | | | | Volume/Number: | 2003 | | | | Issuing Agency: | | | | | Description: | The Illinois Streamflow Gaging Network has been operated by the U.S. Geological Survey (USGS) since the early 1900s. From its inception, the operation of the network has been maintained through a cooperative partnership between the USGS and state and federal agencies. Hydrologic information provided by the network is vital for the general management of Illinois' water resources. Streamflow data are continually used for forecasting floods and droughts; assessing the biological and chemical health of our streams; operating reservoirs, water supply facilities, wastewater treatment facilities, and hydroelectric plants; assessing and predicting the long-term impacts of climate and land-use trends on our streams; and numerous other important uses. The purpose of this study was to conduct a comprehensive evaluation of the use of Illinois streamflow data, with the goal that this information and analysis will be used by the network's cooperating agencies and others for current and future decisions related to funding and content of the network. Evaluations such as this have been conducted in the past, and should continue to be conducted periodically to assess whether the network meets the data needs of users in an effective manner, to assess emerging needs, and to anticipate needed programmatic changes to the network. This report identifies several emerging applications for which more and additional types of stream data likely will be needed, including applications related to stream and watershed restoration and water quality load assessment. However, in general, it is not possible to anticipate many of the future needs of the streamflow gaging program. More often than not, emerging issues will need to use streamflow data far before there is sufficient time to collect data for that specific use. The only way to have adequate data when these needs arise is to maintain a base network at locations that are representative of the streams of Illinois, such that these long-term data are available to meet a broad range of potential needs. This base network of gaging stations also is needed to provide general streamflow information for ungaged streams throughout Illinois. There are thousands of streams in Illinois, whereas the network currently includes roughly 160 continuous-streamflow gages on fewer than 110 of these streams. For other streams, flow characteristics must be estimated from the available gaging records using regional hydrologic principles. Various methods are available to evaluate the effectiveness of specific gaging records for use in this regional transfer of information. This report includes several descriptive measures of the regional value of gage information and also summarizes a numerical evaluation based on information transfer theory. No single approach can effectively describe the broad range of considerations needed to evaluate the regional value of gages. However, it is clear that applications in regional hydrology will need additional data beyond those which are currently supported by the network. Specifically, the base network is noticeably lacking data from small watersheds in rural Illinois. In addition, several hydrologic regions in Illinois have a limited number of gages for use in regional analysis. Two questionnaires were developed to ascertain the importance and uses of the data from the streamflow gaging network. The first questionnaire was distributed to all agencies that provide cooperative funding to the network. The second questionnaire was developed on an Internet Web site to be accessed and filled out by all interested users of Illinois streamflow data. In both questionnaires, the respondents were asked to identify: 1) the types of data that they most frequently use and/or are most critical for their needs; 2) categories of data applications and their relative importance; and 3) the importance of specific gages for their applications. The report provides a ranking of the relative importance of individual gages based on the responses from the questionnaires. The users indicate that river forecasting/flood warning is the overall most important category of application of streamflow data, followed by long-term flow statistics for analyzing hydrologic trends and determining human impacts to streams. However, the majority of users are more likely to use streamflow data for individual project needs such as those related to hydrologic-hydraulic modeling and design, and biological and conservation assessment. Analysis of gaging records indicates that streamflow conditions are not stationary, and vary not only from year to year but also from decade to decade as influenced by climate variability and other factors. More than half of the long-term flow records in rural areas show statistically significant increases in average and low-flow conditions that appear to occur as a result of climate variability. Statewide, over the past 25 years, there has also been an average increase of 18 percent in the estimates of the 100-year flood peak discharge as represented by long-term records. With the decline in the number of crest-stage peak-flow gages and small watershed gages, many of the records available for certain types of hydrologic analysis are older, discontinued gaging records that may not accurately represent the expected present-day, long-term hydrologic conditions. Shorter gaging records, regardless of period of record, also may not fully represent the expected long-term conditions. There is a need for analytical techniques to assess inherent differences in streamflow records and characteristics such as flood frequency that are caused by climatic variability and other factors. The network appears to be meeting most traditional current-use needs. However, there is a need to reinforce the base network, specifically regarding data for relatively small rural watersheds that are needed to address various emerging issues, long-term regional assessment, and peak flood estimation. The size of the overall network would have to be increased an additional 15-20 percent to more effectively address data needs related to small to medium-sized rural watersheds. Also, there is a growing need for new types of stream data to address specific biological and conservation issues such as stream and watershed restoration. This report only addresses streamgaging issues related to flow quantity, and thus there are no conclusions or recommendations related to water quality, precipitation, or other types of hydrologic data. Funding for the Illinois Streamflow Gaging Network is subject to uncertainties, and this is especially the case regarding potential growth or changes to the network. The National Streamflow Information Program (NSIP), initiated by the USGS in 1999, proposed that the USGS eventually would assume the costs of gages that directly meet specific federal interests. However, it is uncertain whether this or other initiatives from traditional funding sources will produce a prominent change in the size and character of the network. More likely, gaging needs for emerging issues will need to be funded from new sources currently not participating in the network. By its nature, it is essential that the base network be funded mainly through state or federal agencies with a long-term commitment to the streamflow gaging program. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2003-05 | | | | ISL ID: | 000000000872 Original UID: 999999994401 FIRST WORD: Evaluation | |
| 84: | | Title: | | | | | Volume/Number: | 2003 | | | | Issuing Agency: | | | | | Description: | The Vermilion River and Little Vermilion River watersheds lie in seven counties in east-central Illinois and west-central Indiana. The drainage areas of the Vermilion River and Little Vermilion River at their confluences with the Wabash River are 1434 and 244 square miles, respectively. The Vermilion River meets the Wabash River at river mile 257.4 and has three tributaries: North Fork, Middle Fork, and Salt Fork. The Little Vermilion River is a direct tributary of the Wabash River at river mile 247.8. Lake Vermilion, a 660-acre impounded reservoir located on the North Fork Vermilion River, is the main municipal drinking water supply for the City of Danville, Illinois. The Little Vermilion River is the main tributary for the 63-acre Georgetown Reservoir, the municipal drinking water supply for the community of Georgetown, Illinois. Approximately 88 percent of the watersheds for both rivers are in agricultural production with approximately 5 percent in forest/woodlands and wetlands. The Illinois State Water Survey (ISWS) conducted a two-year watershed monitoring study of the Vermilion River and Little Vermilion River watersheds for the Vermilion River Ecosystem Partnership-Conservation 2000 Ecosystem Program. The purpose was to assist the partnership by establishing a baseline of hydrologic and water quality data to provide a better understanding of the cumulative impacts of future best management practices implemented in the watersheds. The ISWS established a streamgaging station on the Little Vermilion River near Sidell and monitored the hydrology, sediment, and nitrate-nitrogen (nitrate-N) there and at three U.S. Geological Survey (USGS) streamgaging sites in the Vermilion River watershed (Middle Fork Vermilion River above Oakwood, North Fork Vermilion River near Bismarck, and Vermilion River near Danville). Annual sediment loads for the three Vermilion River watershed stations were approximately three times higher than loads at the Little Vermilion station. The Middle Fork station had the highest sediment loads among the three Vermilion River stations for both project years. The North Fork station had the highest annual nitrate-N load for both monitoring years. In general, annual sediment and nitrate-N loads were lower during the first monitoring year, due to below average spring season runoff. Sampling for three pesticides (atrazine, alachlor, and metolachlor) was done on a weekly basis from June to October 2002. Atrazine was the only pesticide detected during this period. The highest level sampled was 20.93 micrograms per liter (and#956;g/L) and, and all others were below 2.65 and#956;g/L. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2003-06 | | | | ISL ID: | 000000000873 Original UID: 999999994403 FIRST WORD: Sediment | |
| 85: | | Title: | | | | | Volume/Number: | 2003 | | | | Issuing Agency: | | | | | Description: | In the East St. Louis vicinity, the Illinois Department of Transportation Division of Highways (IDOT) owns 56 high-capacity wells that are used to maintain the elevation of the groundwater table below the highway surface in areas in which the highways were constructed below the original land surface. The dewatering systems are located at five sites in the alluvial valley of the Mississippi River in an area known as the American Bottoms. The alluvial deposits at the dewatering sites are about 90 to 115 feet thick and consist of fine sand, silt, and clay in the upper 10 to 30 feet, underlain by about 70 to 100 feet of medium to coarse sand. The condition and efficiency of a number of the dewatering wells became suspect in 1982 on the basis of data collected and reviewed by IDOT staff. Since 1983, IDOT and the Illinois State Water Survey have conducted a cooperative investigation to more adequately assess the operation and condition of the wells, to attempt to understand the probable causes of well deterioration, and to evaluate rehabilitation procedures used on the wells. Work scheduled for FY 00 (Phase 17) included conducting 18 condition-assessment and posttreatment step tests, monitoring of the chemical treatment of 11 wells, and observing and documenting the construction of 2 new (replacement) dewatering wells. Of the 18 step tests conducted, 11 were post-chemical-treatment step tests, 5 were routine condition assessment step tests on existing wells, and 2 were condition assessments on newly constructed wells. The results of the five condition assessment step tests indicated specific capacities ranging from 25.1 to 65.2 gallons per minute per foot (gpm/ft), corresponding to very poor to fair well conditions, respectively. It was recommended that all five wells be chemically treated in FY01. Posttreatment step tests were used to help document the rehabilitation of 11 dewatering wells during FY 00 (Phase 17): I-70 Wells 2A and 8A; 25th Street Wells 2, 3, 4, 5, 7, 8, and 9; and Missouri Avenue Wells 2 and 3. Chemical treatments used to restore the capacity of these seven wells were moderately successful. There was a wide range of improvement in specific capacity per well, ranging from 2 percent to 503 percent improvement, and averaging 124 percent based on specific-capacity data from pre- and posttreatment step tests. A sand pumpage investigation, which was conducted during 15 of the 18 step tests during FY 00, revealed that 25th Street Wells 2, 3, and 4 were pumping sand. These conditions may pose a threat to the long-term operation of these wells, especially 25th Street Well 4. Smaller amounts of sand were found following the step test for 25th Street Wells 2 and 3. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2003-08 | | | | ISL ID: | 000000000874 Original UID: 999999994406 FIRST WORD: Dewatering | |
| 86: | | Title: | | | | | Volume/Number: | 2003 | | | | Issuing Agency: | | | | | Description: | Levels of Lakes Superior, Michigan-Huron, and Erie were assessed to identify key temporal fluctuations in their averages and extreme values during the 1861-2001 period. Behavior of levels of Lakes Michigan-Huron and Superior since 1861 has included vastly different long-term distributions, differences in amount of variability over time, and differences in occurrence times of their record-high and low levels. Record high or low 15-year periods were present on one or more lakes in 64 years, and record events based on 25-year periods were present in 96 of 141 years, both representative of records during a much longer period than if the record events had occurred simultaneously on all lakes. These lake-level differences reflect significant differences in climate conditions between basins, and principally precipitation over time. There were two eras when levels of all lakes exhibited exceptional variability and extreme high and low levels, 1923-1938 and 1973-2001, reflecting considerable climatic instability over the entire Great Lakes basin. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2003-09 | | | | ISL ID: | 000000000875 Original UID: 999999994414 FIRST WORD: Temporal | |
| 87: | | Title: | | | | | Volume/Number: | 2005 | | | | Issuing Agency: | | | | | Description: | This study provides a scientific basis for developing a classification system in support of nutrient criteria development for streams and rivers based on their susceptibility to algal growth. Those streams having high algal biomass as a result of low nutrient concentration are considered susceptible to algal growth. Conversely, streams having low algal biomass and high nutrient concentration are considered less susceptible to algal growth. The process of setting nutrient criteria is complex due to various designated water uses that require different levels of water-quality protection. That complexity is compounded further by the diversity in habitat conditions. Scientists have found that a stream's response to nutrient enrichment depends on various habitat factors such as water velocity, canopy cover along the streambank, and stream width/depth. Habitat conditions may differ considerably from one reach to another and also from season to season. To account for this spatial and temporal variability, monthly aggregated reach-scale habitat conditions were used to develop the classification system. Algae are either the direct or indirect cause of most problems related to nutrient enrichment. In this study, statistical methods were applied to develop a relationship between algal biomass and nutrients (total nitrogen and total phosphorus). Residuals of the developed relationship were considered to be attributable to stream susceptibility to algal growth. Variability of the residuals (i.e., susceptibility values) then can be explained by habitat conditions. Two sets of monitoring data for Illinois streams and rivers were used to develop the statistical models. The susceptibility-habitat model uses habitat monitoring data to predict stream susceptibility, and classify these streams based on their susceptibility. Eventually, the classification system may be used to develop site-specific nutrient standards based on stream tolerance to nutrients. It also can be used to prioritize streams and rivers for the Total Maximum Daily Load (TMDL) and for watershed management purposes. This two-stage model approach was tested on two datasets for Illinois. The Fox River dataset included nine locations on the Fox River in Lake, McHenry, Kane, Kendall, and LaSalle Counties. The Illinois Environmental Protection Agency (IEPA) dataset included extensive habitat factors and nutrient data observed at 142 locations on rivers and streams throughout the state. Those data were used to estimate the nonlinear regression model (f1) for calculating susceptibility based on the habitat factors. Validation entailed comparing predicted susceptibility with 'observed' susceptibility calculated as a residual from the nutrients-algal biomass (chlorophyll a) nonlinear regression model (f2). Various combinations of linear or squared inputs were examined for both f1 and f2 models, and those models giving the best-fit statistics were identified. Results show how the proposed two-stage model could be implemented for watershed classification based on stream susceptibility. Longer, more complete datasets will be required in the future to further test the results and to finetune the models, however. | | | | Date Created: | 5 10 2005 | | | | Agency ID: | CR-2005-02 | | | | ISL ID: | 000000000876 Original UID: 999999994451 FIRST WORD: Development | |
| 88: | | Title: | | | | | Volume/Number: | 2005 | | | | Issuing Agency: | | | | | Description: | The worst winter storm on record in southern Illinois occurred on December 22-23, 2004, and then moved eastward with severe impacts for Indiana, Kentucky, and Ohio. Snowfall amounts from the storm that lasted 30 hours at many locations reached 29 inches, and more than 6 inches fell over a 137,600-square-mile area. Snowfall totals set new records across southern Illinois, the southern half of Indiana, and western Ohio. This prolonged, enormous storm system also produced a major ice storm along its southern edge in Kentucky and Ohio. This record event produced a myriad of impacts totaling $900 million in losses and costs. All aspects of transportation were affected, and the impacts were extreme because the storm occurred at a time of extensive pre-holiday travel. Traffic was paralyzed on numerous interstate highways, and thousands of persons were stranded for 6-36 hours in the bitter cold. Hundreds of airline flights were cancelled or delayed, and trains were halted at several locations. Thousands of vehicular accidents led to numerous injuries, and 17 persons died as a result of the storm. Insured property losses totaled $230 million, ranking the storm as the 32nd most damaging among the nation's 156 catastrophic winter storms since records began in 1949. Airline losses were extremely high, $260 million, and costs to remove snow and ice from highways and streets totaled $133 million. Unusual atmospheric conditions created this unique winter storm. An arctic cold front interacted with a warm, moist air mass along the Ohio River valley, producing the first phase of winter precipitation. A few hours later, a low-pressure center from east Texas moved to the northeast just south of the Ohio River valley, causing the second phase of the storm. Extremely cold arctic air covered the storm area for four days, creating record low temperatures throughout the region that limited recovery efforts. | | | | Date Created: | 5 5 2005 | | | | Agency ID: | CR-2005-03 | | | | ISL ID: | 000000000877 Original UID: 999999994452 FIRST WORD: The | |
| 89: | | Title: | | | | | Volume/Number: | 2002 | | | | Issuing Agency: | | | | | Description: | Soil erosion and nonpoint source pollution runoff rates are estimated using output from the Revised Universal Soil Loss Equation (RUSLE). The underlying influence of climate on surface transport processes as represented in the RUSLE is carried within one constant, the R-factor. It has been assumed that the R-factor is temporally stationary; that is, it does not change with time. The purpose of this study was to process climate information from the most recent decades to update the R-factor, to examine the nature of precipitation variation and change and their impacts on the R-factor over space and time, and, specifically, to test the hypothesis that storm erosivity and the R-factor are temporally stationary. This was addressed by developing a database of precipitation data and related information needed to calculate single-storm erosivity and cumulative R-factor for each half-month of the year and for the total year. In addition the 10-year, single-storm erosive index for each station is provided. The R-factor, a nonlinear, cumulative measure of the erosive energy contained in storm precipitation, was calculated directly from 15-minute rainfall data. However, because of some undocumented quality difficulties with the 15-minute data, single-storm erosivity index statistics for accumulation into R-factors were calculated from more reliable daily data through the use of a power law transfer function. These new R-factors were tested for spatial covariation, which was found to be minimal in even terrain, and related to the limited amount of station R-factor data from past studies. Comparison with past R-factor studies indicated strongly that the methodologies used adequately duplicated old R-factors based on data from the 1930s to the 1950s. General increases observed in R-factors in this study were related to increasing amounts of precipitation and storms with rainfall greater than 12.7 millimeters, especially in the western United States. Mean seasonal patterns of storm precipitation total, duration, intensity, 30-minute and 15-minute maximum intensity, kinetic energy, erosivity, and the numbers of storms also were mapped for the conterminous United States. These analyses showed distinct patterns of precipitation change with seasons and identified regions of strong gradients where climate change first may be noticed. Trend analyses of storm precipitation variables over the 1971-1999 period indicated the lack of temporal stationarity of storm characteristics. Storm duration changes were especially an important cause of the observed changes in storm precipitation totals. However, storm trends in 30-minute maximum intensity seemed to be more important in changing the patterns of storm erosivity. Examination of storm characteristic response to interannual and interdecadal variations also indicated that storm characteristics were responding at these time scales to large-scale climate system forcings. In the winter season, atmospheric teleconnections such as the Pacific/North American Pattern and the North Atlantic Oscillation were shown to influence not only storm track positions and the number of storms at a location, but also the characteristics of individual storms. El Nio and La Nia events of the Southern Oscillation (ENSO events) had distinctive impacts on storm variables in every season of the year. Even the Pacific Decadal Oscillation showed a clear effect on storm characteristics, especially in the western United States. The results of R-factors derived from modern data compared to previous R-factors combined with storm characteristic trend and variability studies indicate conclusively that storm precipitation characteristics change sufficiently over time to warrant an evaluation of the necessity to recalculate R-factors on a regular basis. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2002-08 | | | | ISL ID: | 000000000878 Original UID: 999999994349 FIRST WORD: Spatial | |
| 90: | | Title: | | | | | Volume/Number: | 2003 | | | | Issuing Agency: | | | | | Description: | A dense raingage network has operated in Cook County since the fall of 1989, to provide accurate precipitation for use in simulating runoff for Lake Michigan diversion accounting. This report describes the network design, the operations and maintenance procedures, the data reduction and quality control methodology, a comparison of rainfall amounts obtained via analog chart and data logger, and an analysis of precipitation for Water Year 2002 (October 2001 - September 2002). The data analyses include 1) monthly and Water Year 2002 amounts at all sites, 2) Water Year 2002 amounts in comparison to patterns from network Water Years 1990-2001, and 3) the 13-year network precipitation average for Water Years 1990-2002. Also included are raingage site descriptions, instructions for raingage technicians, documentation of raingage maintenance, and documentation of high storm totals. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2003-01 | | | | ISL ID: | 000000000879 Original UID: 999999994350 FIRST WORD: Continued | |
| 91: | | Title: | | | | | Volume/Number: | 2003 | | | | Issuing Agency: | | | | | Description: | This report documents the structure and the use of an improved version of the Windows-based interface of the unsteady flow model, UNET. This interface was developed by the Illinois State Water Survey for the Office of Water Resources, Illinois Department of Natural Resources. The current version of the interface program can download historic, real-time, and forecasted stage and flow data from U.S. Geological Survey, U.S. Army Corps of Engineers, and National Weather Service Web sites interactively. These data can be used to update an existing Data Storage System (DSS) database or to create new ones. The interface allows the user to create or update gaging station information in a Microsoft Access database. The user can create project files to run the UNET model for historic, design, real-time, and forecasted flood events. The graphing function allows plotting of single and multiple hydrographs, or stage profiles of a single reach and multiple reaches. The utility tools include screen captures, document editing, and DSS file editing. This interface program uses the original UNET generic geometry and boundary condition files to maintain the same level of accuracy as the UNET model, but it also allows the user to change some of the parameters, such as, the simulation time interval, time windows, and numerical Corant number, and etc., in the BC file. Real-time simulation of a flood event simulates flood stage profiles using real-time stage and flow data downloaded from related Web sites. Locations and magnitudes of levee overtopping will be displayed for the lower Illinois River should these occur. The interface program lets the user modify parameters to simulate simple levee failure or two types of complicated embankment failures, overtopping and piping. Simulations also can be performed using the modified levee information, such as breaches or revised crest elevations. The change of water surface elevation induced by modifying levees can be compared with another simulation graphically and also in table format. Stage profiles from all simulations can be plotted together with levee heights on both sides of the channel along the Lower Illinois River to visually show the impacts of particular floods. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2003-03 | | | | ISL ID: | 000000000880 Original UID: 999999994352 FIRST WORD: Flood | |
| 92: | | Title: | | | | | Volume/Number: | 2003 | | | | Issuing Agency: | | | | | Description: | The Illinois State Water Survey (ISWS) conducted sedimentation surveys of Lake Paradise and Lake Mattoon during 2001 in support of an Illinois Clean Lakes Program diagnostic/feasibility study to provide information on the storage and sedimentation conditions of the lakes. Both lakes are owned and operated by the City of Mattoon, which withdraws water from Lake Paradise as the raw water source for distribution of finished water and generally uses withdrawals from Lake Mattoon to maintain a more stable water level in Lake Paradise. The village of Neoga also withdraws water from Lake Mattoon for treatment and distribution. Since June 2001, Reliant Energy has operated a peaker power plant that has withdrawn water from Lake Mattoon for cooling systems. Lake Paradise and Lake Mattoon are located on the main stem of the Little Wabash River, a tributary to the Wabash River. The watershed is a portion of Hydrologic Unit 05120114. The dam for Lake Paradise is about 4 miles southwest of the City of Mattoon at 39 24' 47" north latitude and 88 26' 23" west longitude in Section 8, Township 11N., Range 7E., Coles County. The dam for Lake Mattoon is about 12 miles southwest of the City of Mattoon at 39 20' 00" north latitude and 88 28' 56" west longitude in Section 1, Township 10N., Range 6E., Shelby County.Lake Paradise was surveyed in 1979 and Lake Mattoon in 1980 as part of a previous cooperative study by the ISWS, the Illinois Department of Transportation - Division of Water Resources (DoWR), the Illinois Water Resources Center, and several departments at the University of Illinois at Urbana-Champaign. Lake Paradise lost 835 acre-feet (ac-ft) of its capacity as a result of sedimentation between 1908 and 2001. Approximately 481 ac-ft of this loss has occurred since 1931, which gives an annual sedimentation rate of 9.9 ac-ft since 1931. If this rate of sedimentation continues, the volume of Paradise Lake will be approximately half of the potential 1908 volume in the year 2013 and will be filled completely by sediment in the year 2118. Lake Mattoon lost 1,705 ac-ft of its 1958 capacity as a result of sedimentation between 1958 and 2001, a sedimentation rate of 39.7 ac-ft per year since 1958.If this rate of sedimentation continues, the volume of Lake Mattoon will be approximately half of the 1958 capacity by 2124 and will be completely filled in the year 2291. The sedimentation rates for Lake Paradise and its watershed for the periods 1931-1979, 1979-2001, and 1931-2001 were stable and ranged from 9.5 to 10 ac-ft.The long-term average annual sediment yield from 1931-2001 was 9.85 ac-ft. These sedimentation rates correspond to a rate of loss of lake capacity of 0.51 percent per year (1931-2001). The sedimentation rates for Lake Mattoon and its watershed for the periods 1958-1980, 1980-2001, and 1958-2001 indicate a reduction in net sediment yield from 66.9 ac-ft per year for 1958-1980 to 10.7 ac-ft per year (1980-2001).The long-term average annual sediment yield was 39.5 ac-ft (1958-2001). These sedimentation rates correspond to rates of loss of lake capacity of 0.51 percent per year (1958-1980) and 0.08 percent per year (1980-2001).The long-term average sedimentation rate for the lake is 0.30 percent per year (1958-2001). | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2003-04 | | | | ISL ID: | 000000000881 Original UID: 999999994353 FIRST WORD: Sedimentation | |
| 93: | | Title: | | | | | Volume/Number: | 2003 | | | | Issuing Agency: | | | | | Description: | Episodic controls on sources of ozone precursor gases have been suggested as an alternative to continuous controls as a strategy for reducing ozone concentrations to meet current air quality standards. To show the feasibility of episodic controls to meet ozone air quality standards, it is first necessary to show that it is feasible to forecast surface ozone concentrations with sufficient accuracy and sufficient lead time that episodic controls can be instituted. This study examined the feasibility of a statistical forecast of surface ozone concentrations in the Chicago area (Lake, Cook, and DuPage Counties), based on current concentrations and current and expected weather conditions. Forecast methods were developed using historical data on surface ozone concentrations and meteorological variables measured from 1990-1995. Overall, the study included: andlt;ULandgt; andlt;LIandgt;An extensive literature review and summary. andlt;LIandgt;Documentation of forecast methods used to call Ozone Action Days. andlt;LIandgt;Analysis of Ozone Action Days called in 1995-1997. andlt;LIandgt;Creation of air quality and meteorological databases. andlt;LIandgt;Examination of bivariate relationships between ozone and meteorological variables, including back trajectories on days with high ozone concentrations. andlt;LIandgt;Development of four forecasting approaches involving regression equations and two methods of adjusting or enhancing the results of the regression equations. andlt;LIandgt;Analyses of forecasts based on the four approaches.andlt;/LIandgt;andlt;/ULandgt; | | | | Date Created: | 9 24 2004 | | | | Agency ID: | CR-2003-07 | | | | ISL ID: | 000000000882 Original UID: 999999994354 FIRST WORD: Feasibility | |
| 94: | | Title: | | | | | Volume/Number: | 2005 | | | | Issuing Agency: | | | | | Description: | Prompted by concerns for their county's water resources, Kane County officials funded a multifaceted project to be conducted by the Illinois State Water Survey (ISWS) and Illinois State Geological Survey (ISGS). The project, initiated in May 2002 and scheduled to conclude in May 2007, will provide baseline water-resources data, analyses, and tools for future analyses of water resources available to the county. This report presents and discusses groundwater data and analyses performed as a part of the ongoing investigations in Kane County. Shallow aquifers considered include the unconsolidated sand-and-gravel aquifers and the uppermost bedrock (i.e., the shallow bedrock aquifer). Deeper bedrock aquifers, including the productive Ancell Group and Ironton-Galesville sandstones, are not within the scope of this study, but are discussed in other ISWS reports. The study area includes Kane County and adjacent townships covering a total area of 1260 square miles. A network of 1010 private, public, industrial, and commercial wells was assembled during the inventory phase (May 2002 -August 2003). During the synoptic phase (September -October 2003), water-level measurements were collected from those wells. Waterlevel data were used to construct potentiometric maps for four shallow aquifers: the unnamed tongue below the Batestown Member, the Ashmore Tongue, the aggregated Glasford Formation sands, and the shallow bedrock. Using only groundwater data to constrain the potentiometric surfaces of individual aquifers, the potentiometric surfaces still closely correlated with perennial stream configurations and land-surface topography. The Fox River and Marengo Ridge are the most influential features that determine regional groundwater flow patterns in the county. Groundwater flow west of the Fox River is predominantly to the south and east. East of the Fox River, flow is to the south and west. The interim potentiometric maps can be used to characterize regional groundwater flow, identify areas of groundwater recharge and discharge, determine regional effects of groundwater withdrawals, and provide a baseline for comparison with future groundwater conditions. The maps will be useful in developing a conceptual model of groundwater flow and mathematical groundwater flow models for a wide range of analyses, including aquifer development scenarios. In 2003, 46 high-capacity wells accounted for 6.3 billion gallons or 97 percent of the total reported groundwater withdrawals of 6.5 billion gallons from the shallow aquifers in Kane County. If unreported withdrawals also are estimated, total withdrawals in 2003 may have been as much as 6.9 billion gallons. Groundwater withdrawals appear to have locally influenced the head surfaces, particularly in east-central and southeastern Kane County. Areas of relatively low head in the shallow bedrock aquifer may reflect large withdrawals from the aquifer, hydraulically connected units, and/or areas of significant discharge to the Fox River. A preliminary analysis of aquifer connections was based on potentiometric surfaces. Areas of potential aquifer connection were identified solely on similarity of measured heads. However, to refine this analysis, aquifer connections need to be evaluated further, taking into account aquifer concurrence and predicted thicknesses of intervening clay-rich geologic deposits. Nomenclature previously used to describe the aquifers of Kane County needs to be reevaluated to address vertical and horizontal aquifer continuity. That reevaluation will require additional geological modeling to more fully characterize and differentiate hydrostratigraphic units of importance such as sands in the Tiskilwa and Glasford Formations. Interim potentiometric maps presented in this report are subject to change as the conceptual hydrostratigraphy evolves. If the interim maps require changes, final versions will be released in the final report on groundwater investigations in 2007. | | | | Date Created: | 5 12 2005 | | | | Agency ID: | CR-2005-04 | | | | ISL ID: | 000000000883 Original UID: 999999994453 FIRST WORD: Kane | |
| 95: | | Title: | | | | | Volume/Number: | 2000 | | | | Issuing Agency: | | | | | Description: | The First Sino - U.S. Joint Workshop on Sediment was organized with strong support from both the United States and China, with the intention to strengthen information exchange and cooperation on research on emerging hydro-environmental problems. The Natural Science Foundation of China has established a national key research project, Study on Mechanisms of River Sedimentation, Disasters, and Control Strategies in China, and is interested in establishing a bilateral cooperation program with the United States on sediment transport and sediment-induced disasters. A joint workshop was considered to be an effective approach for scientists and engineers from both countries to exchange knowledge and experience, to explore research and educational needs, and to initiate future collaborations. In a three-day meeting in Beijing, China, followed by a five-day field study in the Loess Plateau along the middle reach of the Yellow River, the participants exchanged information on sediment-related topics and identified opportunities for future research and cooperation. A major emphasis of the workshop was to promote direct discussions, and the workshop sessions were structured accordingly. The format worked very well and resulted in ample exchange of experiences and needs for future studies. This report presents information from the workshop and summaries of discussions from the meeting in Beijing. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | IEM-2000-01 | | | | ISL ID: | 000000000892 Original UID: 999999994075 FIRST WORD: Post | |
| 96: | | Title: | | | | | Volume/Number: | 2000 | | | | Issuing Agency: | | | | | Description: | An anomalously warm El Nio event developed in the eastern tropical Pacific Ocean during May-August 1997. El Nio events have become recognized as capable of having major effects on atmospheric circulation patterns over North America and elsewhere, leading to predictable outcomes for future seasonal weather conditions. The source of the nation's official long-range predictions, the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center (CPC), began issuing forecasts in May 1997 about the event's development and growth to near record proportions. The emerging El Nio was expected to match or exceed the El Nio of 1982-1983, the strongest of this century. Predictions of the future weather conditions expected over the nation, as a result of El Nio's influence on the atmosphere, also were issued by CPC beginning in June 1997. Basically, these and subsequent predictions called for a fall, winter, and early spring in the Midwest that would have above normal temperatures and below normal precipitation. The predictions also called for storms and precipitation to increase in other parts of the nation, particularly in the South and West Coast areas. Media and wide public interest in the evolving record event brought inquiries to the Midwestern Climate Center (MCC) during June 1997. At that time, MCC leadership launched special studies and efforts related to the El Nio event, which included: a climatological reanalysis of past El Nio events and the associated weather conditions in the Midwest, the issuance of outlooks based on these studies, and the collection and analysis of data on the impacts caused by the El Nio-generated weather conditions in the Midwest. This decision was in keeping with past MCC research policy that has focused on assessing extreme Midwestern weather conditions like the 1988 drought (Changnon, 1991a and b), the 1993 flood (Kunkel, 1996; Changnon, 1996), and the 1995 heat wave (Kunkel et al., 1996; Changnon et al., 1996). These studies also focused on identifying and quantifying the impacts of these extreme events. The findings of such activities help the MCC respond rapidly and accurately to numerous regional inquiries for data and information about such extreme events. They also help the MCC prepare for effectively addressing similar events in the future. During the El Nio event, beginning in June 1997 and ending in May 1998, the MCC scientists issued several climate outlooks about future Midwestern conditions. These were basically probabilistic-based statements and focused on the winter of 1997-1998, spring 1998, and summer 1998 outcomes. During the El Nio event, the MCC staff collected and recorded all the relevant weather data for the Midwest. Data defining the impacts of El Nio-generated weather events were collected from August 1997 through August 1998. This report presents information about MCC activities related to El Nio in 1997-1998. It includes three sections: the predictive outlooks issued, a climatic assessment of monthly and seasonal weather conditions during the event, and a description of societal and economic impacts caused in the Midwest. Recommendations are offered in the section "Conclusions and Recommendations" for addressing future El Nio events and the handling of long-range predictions. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | DCS-2000-01 | | | | ISL ID: | 000000000893 Original UID: 999999994304 FIRST WORD: El | |
| 97: | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | Brochure describing the research and services available from the Midwestern Regional Climate Center (MRCC) help to better explain climate and its impacts on the Midwest, provide practical solutions to specific climate problems, and allow us to develop issues-based climate information for the Midwest. Our data and information focus primarily on applications to climate-sensitive sectors and scientific research. In addition to providing on-line access to the interactive, subscription-based Midwestern Climate Information System (MICIS), the MRCC web site provides climate statistics for the Midwest and links to climate resources around the country. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | IEM-2001-01 | | | | ISL ID: | 000000000894 Original UID: 999999994318 FIRST WORD: Midwestern | |
| 98: | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | Brochure describes the Illinois State Water Survey (ISWS), which has been a leader in the study of water resources for more than a century. Founded in 1895, its original mission was to survey the waters of Illinois to trace the spread of waterborne disease, ensure health and safety of public water supplies, improve wastewater treatment, and help develop sanitary standards for drinking water. The mission and scope have expanded to include varied scientific research and service programs relating to water and atmospheric resources of interest to Illinois. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | IEM-2001-02 | | | | ISL ID: | 000000000895 Original UID: 999999994319 FIRST WORD: Science | |
| 99: | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | The Benchmark Sediment Monitoring Program for Illinois Streams was initiated by the Illinois State Water Survey in 1981 to generate a long-term database of suspended sediment transport. The program is now part of the Water Survey's Water and Atmospheric Resources Monitoring (WARM) Network, which monitors the climate, soil moisture, surface water, ground water, and sediment throughout Illinois. This report summarizes the suspended sediment data collected for the program during Water Years 1994 and 1995. All the techniques used in the data collection process and laboratory analyses are based on U.S. Geological Survey procedures and techniques. The report appendices present tables of instantaneous suspended sediment measurements, particle size analysis, sediment transport curves, and plots of instantaneous sediment concentrations for the period of record for the current monitoring stations. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | DCS-2001-01 | | | | ISL ID: | 000000000896 Original UID: 999999994325 FIRST WORD: Benchmark | |
| 100: | | Title: | | | | | Volume/Number: | 2001 | | | | Issuing Agency: | | | | | Description: | The Benchmark Sediment Monitoring Program for Illinois Streams was initiated by the Illinois State Water Survey in 1981 to generate a long-term database of suspended sediment transport. The program is now part of the Water Survey's Water and Atmospheric Resources Monitoring (WARM) Network, which monitors the climate, soil moisture, surface water, groundwater, and sediment throughout Illinois. This report summarizes the suspended sediment data collected for the program during Water Years 1996 and 1997. All the techniques used in the data collection process and laboratory analyses are based on U.S. Geological Survey procedures and techniques. The report appendices present tables of instantaneous suspended sediment measurements, particle size analysis, sediment transport curves, and plots of instantaneous sediment concentrations for the period of record for the current monitoring stations. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | DCS-2001-02 | | | | ISL ID: | 000000000897 Original UID: 999999994326 FIRST WORD: Benchmark | |
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