Organization | • | Illinois State Water Survey | [X] |
| | | | Title: | | | | | Volume/Number: | 2005 | | | | Issuing Agency: | | | | | Description: | A key element of the Illinois Generic Management Plan for Pesticides in Groundwater was the use of a statewide map of aquifer sensitivity to contamination by pesticide leaching. This map included soil properties (hydraulic conductivity, the amount of organic matter within individual soil layers, and drainage class) from a digital soil association map and hydrogeologic properties to a depth of 50 feet. The map displayed six mapped units or levels of aquifer sensitivity, and each map unit was subdivided into two map subunits. Each subunit had a distinct combination of soil and hydrogeologic properties. Prior to the implementation of the Generic Plan, the statewide map was tested by sampling shallow groundwater for pesticides from a dedicated monitoring well network. To test this mapping strategy efficiently, a stratified random sampling plan was adopted that focused on the three most sensitive map units. Project goals were to provide data to test the utility of the aquifer sensitivity map to predict pesticide occurrence and to understand pesticide occurrence in shallow groundwater. All monitoring wells were located near agricultural production fields (most within 10 feet of corn and soybean fields) where the only known source of pesticides were those pesticides used in normal agricultural production. Most studies of pesticide contamination covering a broad geographic area sample water-supply wells, and this study using monitoring wells was designed to generate data that might provide a unique perspective on the occurrence of pesticides in shallow groundwater. Prior to the completion of the entire monitoring network, a one-time sampling program of monitoring wells was conducted to assess the distribution of pesticide occurrence across the various units of aquifer sensitivity, and a time-series sampling program was conducted to assess the temporal variability of pesticides in shallow groundwater. For the one-time sampling program, 159 samples were collected from 159 wells from September 1998 through February 2001. For the time-series sampling program, 215 samples were collected from 21 wells from October 1997 through July 2000. These groundwater samples were analyzed for 14 pesticides but no pesticide degradates. In addition, groundwater samples were collected to characterize cations and anions, including nitrate-nitrogen. Data from these initial sampling programs showed that pesticides were detected in 16 to 18% of the samples. Atrazine was the most commonly detected pesticide, followed by metolachlor, butylate, and bromacil. Only one sample had a concentration of a pesticide (atrazine) that exceeded a federal drinking water standard. Most detections were at concentrations less than 1 g/L. Pesticide occurrence was generally dependent on sampling time. The strongest temporal relationship was between post-application (June through October) versus other time frames (November through May). Pesticide occurrence during post-application months was three times higher than during other months. Pesticide occurrence was three times more common in samples when the depth to aquifer material was mapped as less than 20 feet than when the depth to aquifer material was mapped as 20 to 50 feet. Thus, pesticide occurrence was found to be dependent on depth to uppermost aquifer material or the hydrogeologic factor of the tested map. Pesticide occurrence was not dependent on the combined soil and hydrogeologic factors of the tested map. Thus, the new map was not a useful predictor of pesticide occurrence. The median and range of anion and cation concentrations for both sampling programs were similar, except for nitrate-nitrogen concentrations. The median nitrate-nitrogen concentrations for both programs differed slightly, but were less than 3.0 mg/L, which is well below the 10 mg/L maximum contaminant level for nitrate-nitrogen. The nitrate and sulfate concentrations were not uniform across the six subunits. Based on the neural network analysis of the one-time sampling data, the time of sample collection and well depth appeared to be the best parameters for predicting pesticide concentration. Depth to uppermost aquifer material and depth to water also were significant. Aquifer sensitivity to contamination and pesticide leaching class values were not able to predict contamination potential independently; however, their presence with other input parameters improved the prediction of contamination by the neural network analysis. | | | | Date Created: | 1 24 2006 | | | | Agency ID: | COOP-20 | | | | ISL ID: | 000000000959 Original UID: 999999994473 FIRST WORD: Illinois' | |
| | | Title: | | | | | Volume/Number: | 1971 | | | | Issuing Agency: | | | | | Description: | This report presents the climatology of Illinois tornadoes based on data from the 1916-1969 period, and offers a variety of general interest tornado facts. Illinois ranks eighth nationally in the number of tornadoes, but first in deaths and second in tornado damages. On the average, there are 10 tornadoes per year, occurring on five days. The annual average death rate from these storms is slightly over 19with an injured average of 110 people. A majority (65 percent) of Illinois tornadoes occur during March through June, with 15-21 April being the prime 7-day period. Over 40 percent occur between 1500 and 1800 CST, and 65 percent take place from 1400-2000 CST. Five of the outstanding Illinois tornado days of the 1916-1969 period are discussed in detail, including the famed Tri-State tornado of 18 March 1925, the most devastating tornado in the United States since systematic collection of tornado data began in 1916.The general information includes, among other items, basic definitions pertinent to tornadoes, safety precautions, formulation of a tornado forecast, and methods for remote detection of tornadoes. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | C-103 | | | | ISL ID: | 000000000738 Original UID: 999999993755 FIRST WORD: Illinois | |
| | | Title: | | | | | Volume/Number: | 1999 | | | | Issuing Agency: | | | | | Description: | A field-scale project in Mason County, Illinois, was performed to monitor the movement of nitrate in ground water beneath an irrigated field. Chemical tracers were used to assess the migration of solutes both laterally and vertically under the influence of an irrigation well and to determine the amount of recycling at a site due to irrigation pumpage and the amount of off-site transport of nitrate due to regional ground-water flow. Water samples from the sand aquifer at the site reveal considerable spatial and temporal heterogeneity in aqueous chemistry. Recharge is rapid in this system, and it is probable that the water chemistry of the recharge water also is variable spatially and temporally; it is especially influenced by agricultural practices. Nitrate (NO3-) concentrations are elevated in a zone between approximately 15 and 30 feet (ft) beneath the surface, although this zone was not persistent laterally or with time. The maximum nitrate concentrations in this zone were slightly greater than 20 milligrams per liter (mg/L) as nitrogen, well above the drinking water standard of 10 mg/L. Nitrate was generally absent below 30 ft in the aquifer, probably due to denitrification reactions. The tritium data suggest that vertical movement of solutes in the aquifer is rapid, and that there has been enough time to transport solutes from the surface or soil zone to depths in excess of 100 ft. Because drinking-water wells generally are screened well below the zone of elevated nitrate concentrations in this area, it appears that fertilizer applications do not have a negative effect on drinking-water quality for most homeowners. From the results of tracer tests, the effects of irrigation pumping on solute transport are measurable but not substantial. Tracer movement both horizontally and vertically was slight under pumping conditions, less than 10 ft horizontally and between 1 and 2 ft vertically about 100 ft from the irrigation well after three days of pumping. The vast majority of nitrate applied in this area is not being recycled through the irrigation wells. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | RR-128 | | | | ISL ID: | 000000000947 Original UID: 999999994252 FIRST WORD: Impact | |
| | | Title: | | | | | Volume/Number: | 1987 | | | | Issuing Agency: | | | | | Description: | This investigation is the first of three phases of a ground-water management study. In this report, effects of irrigation and drought on the ground-water resources of Illinois are examined. Irrigation water use for five soil types is estimated from a monthly water budget model on the basis of precipitation and temperature data from the last 30 years at selected weather stations across Illinois. Moisture deficits are computed for each soil type on the basis of the water requirements of a corn crop. It is assumed that irrigation is used to make up the moisture deficit in those places where irrigation systems already exist. Irrigation water use from each township with irrigated acreage is added to municipal and industrial ground-water use data and then compared to aquifer potential yields. The spatial analysis is accomplished with a statewide geographic information system. An important distinction is made between the seasonal effects of irrigation water use and the annual or long-term effects. The model is tested for its sensitivity to weather variation; seasonal water deficits are calculated by using data from extreme growing seasons and extended drought periods. The effect of increasing the amount of irrigated land by 50 percent is also considered for normal weather conditions and droughts. The effect of variable irrigation demand on ground-water resources is expressed as the ratio of ground-water use to ground-water potential yield for each township. This is done to highlight regions most susceptible to ground-water stress because of drought or increased irrigation by showing where use could exceed yield. The sensitivity of the results is not tested for variations in spatial aggregation. This will be one of the primary tasks in subsequent study phases. Results show that irrigation is a substantial seasonal consumptive ground-water use in Illinois, with the potential for growth. However, present effects appear to be localized and highly dependent on weather conditions. Some potential for seasonal or temporary overpumpage may exist in the heavily irrigated areas during years with below-normal precipitation or during extended droughts. The aquifers being used for irrigation appear to have the ability to recover from present irrigation demands without suffering significant depletion, implying that the annual effect of irrigation is currently relatively minimal. The exception to this may be during extended drought periods, especially if widespread expansion of irrigation practices also occurs in the state. A 50 percent expansion of irrigation would appear to have surprisingly little additional impact on ground-water resources under most climatic conditions. That degree of growth around currently irrigated land would result in expanded irrigation areas still within reach of the productive, high-yielding aquifers already being pumped for irrigation. A much larger degree of irrigation expansion into areas with heavier-textured soils is possible in Illinois. The availability of ground-water would be a major limiting factor in the speed and direction of that expansion. That kind of massive irrigation expansion is not considered in this report; however, its effects on the state's ground water are assumed to be considerable and will be addressed in subsequent study phases. The Chicago metropolitan area stands out as a major region of overpumpage, but not because of irrigation. Variable irrigation pumpage does appear to consistently affect several other regions, most notably parts of Mason, Kankakee, Tazewell, Lee and Whiteside Counties. The degree to which these counties are affected by irrigation depends largely on weather conditions. For all these counties, with the possible exception of Kankakee, surficial sand and gravel aquifers are the most susceptible to stress from drought and irrigation water use. Shallow bedrock aquifers may also be impacted by irrigation in parts of Kankakee County. The impact of an extended drought is likely to be more widespread and inconsistent because of the multiple effects of increased water use for irrigation and other demands, and reduced ground-water storage. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | RI-109 | | | | ISL ID: | 000000000936 Original UID: 999999993972 FIRST WORD: Impacts | |
| | | Title: | | | | | Volume/Number: | 2004 | | | | Issuing Agency: | | | | | Description: | This report presents extensive information from recently published findings related to the following two critical questions about climate change: andlt;ULandgt; andlt;LIandgt;What will the future climate be like? andlt;LIandgt;What will the effects be, both good and bad? andlt;/LIandgt;andlt;/ULandgt;Chapter 1 introduces the two main chapters of the report that provide insights to the above two critical questions about climate change. Chapter 2 provides examples from a wide spectrum of scientists, scientific organizations, and the media of contradictions and confusion about whether human-induced climate change is predictable over the time scale of a century. It then explains why such climate change is unpredictable in the traditional deterministic sense. It describes the climate system and documents improvements and remaining uncertainties of global climate models relevant to evaluating human-induced climate change on the century time scale. Climate measurements in Illinois since the mid-19th century document major climate swings not evident in a 50- to 100-year record. Illinois is no warmer or wetter today than it has been over the last 150 years, and extreme precipitation events across the country are reported to be no more frequent than they were a century ago. Important conclusions from these data are that i) regional climate trends over the past 50-100 years that are consistent with theoretical expectations of an enhanced greenhouse effect (for example, higher precipitation and more heavy rainfall events in northern mid-latitudes) do not necessarily establish causality; and ii) global warming has not resulted in warming in all parts of the globe. Chapter 3 focuses on the issue of economic impacts of weather and climate in the United States (US). The first section addresses known financial impacts of recent (1950-2000) weather and climate conditions. Descriptions follow of temporal trends of weather and climate extremes and their impacts, causes for on-going increases in economic impacts, and estimates of future financial impacts under a changed climate. The frequency of most types of storms and droughts either has not changed or has decreased during 1940-2000. Yet, losses (1997 dollars) for most storm types have increased over time. Possible causes for increased losses include a shift in climate related to global warming, questionable insurance practices, and aging infrastructure. Study also shows increasing losses due to societal factors, including population growth, more people residing in more weather vulnerable areas, shifts in business-product development that are weather sensitive, and growing wealth. Various studies of weather- and climate-induced economic impacts were used to develop national loss and gain estimates. Projections for the US, depending upon varying assumptions about the future climate (combinations of warmer, wetter, drier, or more storms), show annual climate-related losses ranging from $2 billion to $69 billion, and others estimate annual gains of $30 billion to $40 billion. In all cases, the projected outcomes are small in relation to the expected Gross Domestic Product. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | IEM-2004-01 | | | | ISL ID: | 000000000949 Original UID: 999999994422 FIRST WORD: Insights | |
| | | Title: | | | | | Volume/Number: | 1991 | | | | Issuing Agency: | | | | | Description: | Biweekly and total irrigation amounts and irrigation scheduling practices were monitored at representative sites in central Illinois during the 1988 and 1989 growing seasons. The purpose was to gather baseline information on average quantities of irrigation water used in normal and drought years and on the general efficiency of irrigation operations in the subhumid climate of Illinois. Soil water-holding capacity is the most important factor in determining irrigation amounts, explaining about 65 percent of the variability in irrigation totals. Other important factors in explaining irrigation variations include weather changes, individual farmer idiosyncrasies, and crop differences. In general, irrigation farmers in Illinois appear to be applying appropriate amounts of irrigation water at appropriate times in the growing season, based on their soil type, crop type, and total evaporative losses. | | | | Date Created: | 9 24 2004 | | | | Agency ID: | RR-118 | | | | ISL ID: | 000000000938 Original UID: 999999993981 FIRST WORD: Irrigation | |
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