Geology topics

Dale M. Robertson

Publications and source records attributed to Dale M. Robertson.

160 records · Page 9Linked to original sources

USGS1998

Hydrology, water quality, and phosphorus loading of Kirby Lake, Barron County, Wisconsin

In 1992, residents near Kirby Lake, located about five miles northwest of Cumberland, in Barron County, Wisconsin, formed the Kirby Lake Management District. The Lake District immediately began to gather information needed for the preparation of a comprehensive lake-management plan that would be used to protect the natural and recreational assets of the lake. The Lake District completed a land-use inventory of the watershed and an evaluation of available lake water-quality data. The land-use data were used to assess the potential contribution of nutrients to the lake from the watershed. The evaluation of lake water-quality data, which were collected as part of the Wisconsin Department of Natural Resources (WDNR) Self-Help Monitoring Program, indicated the lake has relatively good water quality. Before a comprehensive lake-management plan could be prepared, however, a better understanding of several aspects of the lake and its surroundings was needed. To address those aspects including the definition of the lake's hydrology and the principal sources of nutrients, and the relation of the lake's water quality to nutrient loading the U.S. Geological Survey, in cooperation with the Lake District and the WDNR (through a Lake Management Planning Grant), conducted a study of Kirby Lake and its watershed. This Fact Sheet presents the results of that study.

Wisconsin↗

USGS1998

Water-quality and lake-stage data for Wisconsin lakes, water year 1997

The U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many years, provide a data base for developing an improved understanding of the water quality of lakes. To make these data available to interested parties outside the USGS, the data are published annually in this report series. The location of water-quality and lake-stage stations in Wisconsin for water year 1997 are shown in figure 1. A water year is the 12-month period from October 1 through September 30. It is designated by the calendar year in which it ends. Thus, the period October 1, 1996 through September 30, 1997 is called 'water year 1997'. The purpose of this report is to provide information about the physical and chemical characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected include measurements of lake stage and in-lake water quality. Graphs of Secchi depths, surface total-phosphorus and chlorophyll-a concentrations versus time are usually included for lakes with two or more years of data. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive information for each lake includes: location of the lake, area of the lake's watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published in another volume: 'Water Resources Data-Wisconsin, 1997'.

Wisconsin↗

USGS1998

Evaluation of the surface-water sampling design in the Western Lake Michigan Drainages in relation to environmental factors affecting water quality at base flow

Eight stream sites (Fixed Sites) were chosen to describe the variability in the water quality of the Western Lake Michigan Drainages (WMIC) Study Unit of the National Water-Quality Assessment program. These sites were chosen in areas (Relatively Homogeneous Units) dominated by unique combinations of the environmental factors thought to be most important in influencing water quality; namely, land use, surficial deposits, and bedrock type. A study was designed to determine (1) the applicability of streamflow, nutrient, and suspended sediment data regularly collected at these eight sites describing the variability in these characteristics throughout the Study Unit during base-flow conditions and (2) the applicability of the interpretive results made from data collected at these few sites to streams throughout the Study Unit. This was done by sampling the Fixed Sites and an additional 83 sites in Relatively Homogeneous Units throughout the Study Unit during summer base-flow conditions. Data collected at the Fixed Sites described the range in water-quality characteristics (stream-flow and concentrations of nutrients and suspended sediment) in the WMIC Study Unit and, in general, represented the water quality from the Relatively Homogeneous Units from which they were chosen. The result from the eight Fixed Sites agreed with those found for all of the sites; namely, that these water-quality characteristics in streams throughout the WMIC Study Unit during base-flow conditions are influenced primarily by the land use and surficial deposits in their drainage basins. General basin characteristics (bedrock information, topographic gradient, and basin size) were not important factors in explaining the variability in these water-quality characteristics during base-flow conditions, but may be important factors for other characteristics measured at Fixed Sites, such as major ions, and may be important during higher flow. In general, streams in agricultural areas had the poorest water quality; that is, they contained the highest concentrations of total phosphorus, total Kjeldahl nitrogen, and suspended sediment. Streams in urban and mixed agriculture/forested areas had moderate water quality, exhibiting the highest concentrations of total phosphorus, total Kjeldahl nitrogen, and suspended sediment, and the lowest base flow. In general, water quality in streams in areas with sandy/sand and gravel deposits and loamy deposits were very similar. Within the forested areas, streams in areas with a higher percentage of forested wetlands had lower base flow, higher concentrations of total Kjeldahl nitrogen, and lower concentrations of dissolved nitrite plus nitrate than streams in areas with a lower percentage of forested wetlands. The variability in water quality throughout the WMIC Study Unit during base-flow conditions could be described very well by subdividing the area into Relatively Homogeneous Units and sampling a few streams with drainage basins completely within these homogeneous units. This subdivision and sampling scheme enabled the differences in water quality to be directly related to the differences in the environmental characteristics that exist throughout the Study Unit.

Michigan, Wisconsin↗

USGS1997

Regionalized loads of sediment and phosphorus to lakes Michigan and Superior—high flow and long-term average

Daily loads of suspended sediment and total phosphorus for the 10-year, 1-day design high flow and average of the 16-year period (1975 to 1990) were computed for 18 well-monitored tributaries to Lake Michigan and Lake Superior by use of constituent-transport models. The loads from these 18 reference tributaries were used to estimate the loads from all the United States tributaries (with drainage basins greater than 325 km 2 ) to Lake Michigan and Lake Superior by selection of a reference tributary with the most similar physical characteristics and use of a unit-area yield. Statistical comparisons between computed yields and environmental factors were used to determine the physical characteristics that were most influential in selecting a reference tributary. Suspended sediment yields were affected primarily by river gradient and secondarily by the texture of surficial deposits, whereas total phosphorus yields were affected primarily by the texture of surficial deposits and secondarily by river gradient. Average total phosphorus loads were greatest in rivers entering the middle to southern part of Lake Michigan, especially those draining clayey surficial deposits in agricultural areas. During high flow, loads of phosphorus and suspended sediment from tributaries entering the southwestern part of Lake Superior dominate the total input of these constituents because of the steep gradients of the rivers and the clayey surficial deposits that they drain. These loads were used to compute regional loads and to rank the tributaries on the basis of their respective loads during a specified high flow and over extended periods.

Michigan, Illinois, Wisconsin↗

USGS1997

Sedimentary phosphorus cycling and a phosphorus mass balance for the Green Bay (Lake Michigan) ecosystem

The tributaries of Green Bay have long been recognized as major sources of phosphorus in the Lake Michigan basin. The status of Green Bay as a sink or source of phosphorus for Lake Michigan proper has been less well defined. The bay receives nearly 70% of its annual load of phosphorus (700 metric tons (t)??year-1) from a single source: the Fox River. Most of this phosphorus is deposited in sediments accumulating at rates that reach 160 mg??cm-2??year-1 with an average of 20 mg??cm-2 year-1. The phosphorus content of these sediments varies from <5 to >70 ??mol??g-1. Deposition is highly focused, with ???0% of the total sediment accumulation and at least 80% of the phosphorus burial occurring within 20% of the surface area of the bay. Diagenetic and stoichiometric models of phosphorus cycling imply that >80% of the phosphorus deposited is permanently buried. External phosphorus loading to the bay is combined with sediment fluxes of phophorus to arrive at a simple phosphorus budget. Green Bay acts as an efficient nutrient trap, with the sediments retaining an estimated 70-90% of the external phosphorus inputs before flowing into Lake Michigan.

Canadian Journal of Fisheries and Aquatic Sciences↗

USGS1997

Field-scale tests for determining mixing patterns associated with coarse-bubble air diffuser configurations, Egan Quarry, Illinois

The U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers, Chicago District did field-scale tests in August-September 1996 to determine mixing patterns associated with different configurations of coarse-bubble air diffusers. The tests were done in an approximately 13-meter deep quarry near Chicago, Ill. Three-dimensional velocity, water-temperature, dissolved oxygen concentration, and specific-conductivity profiles were collected from locations between approximately 2 to 30 meters from the diffusers for two sets of five test configurations; one set for stratified and one set for destratified conditions in the quarry. The data-collection methods and instrumentation used to characterize mixing patterns and interactions of coarse-bubble diffusers were successful. An extensive data set was collected and is available to calibrate and verify aeration and stratification models, and to characterize basic features of bubble-plume interaction.

Conference Paper↗

USGS1996

Sources and transport of phosphorus in the Western Lake Michigan Drainages

In 1991, the U.S. Geological Survey (USGS) began full implementation of the National Water-Quality Assessment (NAWQA) Program. The goals of the NAWQA program are to (1) provide a nationally consistent descrip- tion of water-quality conditions for a large part of the Nation's water resources, (2) define long-term trends (or lack of trends) in water quality, and (3) identify, describe, and explain, as possible, the major factors that affect the observed water-quality conditions and trends (Hirsch and others, 1988). To fulfill the goals of the NAWQA program, the USGS plans to examine 60 areas (study units) across the United States on a rotational cycle. The first 20 of these study units began intensive investigations in 1991. One of these study units is the Western Lake Michigan Drainages (WMIC) (fig. 1).

Michigan, Wisconsin↗

USGS1996

Water-quality assessment of the western Lake Michigan drainages: Analysis of available information on nutrients and suspended sediment, water years 1971-90

In 1986, Congress appropriated funds for the U.S. Geological Survey (USGS) to develop the pilot phase of the National Water-Quality Assessment (NAWQA) Program. The long-term goals of this program are to (1) provide a nationally consistent description of current water-quality conditions for a large part of the Nation's water resources; (2) define. long-term trends (or lack of trends) in water quality; and (3) identify, describe, and explain, as possible, the major factors that affect the observed water-quality conditions and trends. To fulfill the goals of the NAWQA program, the USGS plans to examine 60 areas (study units) across the United States during full implementation of the program. In 1991, the NAWQA program went into full implementation with the intensive investigation of 20 of these study units; one of these study units is the Western Lake Michigan Drainages (WMIC) study unit.

Michigan, Wisconsin↗

USGS1996

Use of frequency-volume analyses to estimate regionalized yields and loads of sediment, phosphorus, and polychlorinated biphenyls to lakes Michigan and Superior

In most rivers, transport of various constituents occurs largely during short-term, high-intensity events. A method is described to make regionalized estimates of the long-term average loads of selected streamwater constituents, as well as loads occurring during high-flow events with specified recurrence intervals. This method is used to estimate the load of suspended sediment, total phosphorus, and sediment-borne constituents, such as poly chlorinated biphenyls (PCB's), from all the rivers in the United States that drain into Lake Michigan and Lake Superior whose drainage basins are greater than 325 square kilometers. Statistical comparisons of estimated loads and environmental factors indicate that suspendedsediment loads were primarily affected by river gradient and secondarily affected by the texture of surficial deposits, whereas total phosphorus loadings were primarily affected by the texture of surficial deposits and secondarily affected by river gradient. Total phosphorus loads were highest in rivers entering into the middle to southern part of Lake Michigan, especially rivers in areas draining clay surficial deposits and agricultural areas. During high flow, inputs of phosphorus and suspended sediment from rivers entering the southwestern part of Lake Superior become very important to the total input of these constituents; these rivers have steep gradients and drain surficial deposits with high clay content. The single largest contributor of PCB's during the entire period and during each type of high-flow event was the Fox River, which supplied 46 to 64 percent of the total PCB load to both lakes.

Michigan, Wisconsin↗

USGS1996

Phosphorus dynamics in Delavan Lake Inlet, southeastern Wisconsin, 1994

Removal of rough fish from Delavan Lake Inlet in southeastern Wisconsin transformed the inlet from a shallow, turbid-water system with few macrophytes to a clear-water system with an abundance of macrophytes and increased phosphorus concentrations. To understand the changes in the phosphorus dynamics, the U.S. Geological Survey and the U.S. Army Corps of Engineers, in cooperation with the Town of Delavan, constructed a detailed phosphorus budget for the inlet for April through September 1994. The budget included inputs from the drainage basin, atmosphere, sediments (as a function of pH and the fraction of the day under anoxic conditions), and ground water. Laboratory studies estimated phosphorus flux rates under various conditions. Field studies documented ambient conditions in the inlet and fluxes of phosphorus into and out of the inlet. Phosphorus released from the sediments was estimated by coupling the flux rates, estimated in the laboratory, with ambient conditions in the inlet. The detailed phosphorus budget indicated that the increase in phosphorus concentrations was caused primarily by elevated pH resulting from increased photosynthetic activity of the macrophytes and a high release of phosphorus from the sediments. The release of phosphorus from the sediments was the largest source of phosphorus to the inlet in the spring and summer of 1994 and in other years of low to near normal runoff; however, in years of high runoff, phosphorus input from the inlet's drainage basin was the largest source of phosphorus. A less-detailed phosphorus budget constructed for the period from February 1993 to September 1994 demonstrated that, over the entire year, runoff from the drainage basin was the dominant source in the phosphorus budget. During April-September 1994, the input of phosphorus from the inlet may especially affect the summer productivity in Delavan Lake because almost 80 percent of the phosphorus loading during this time was in the form of dissolved orthophosphate.

Wisconsin↗

USGS1996

Evidence of recent warming and El Nino-related variations in ice breakup of Wisconsin lakes

Ice breakup dates from 1968 to 1988 were examined for 20 Wisconsin lakes to determine whether consistent interannual and long-term changes exist. Each ice record had a trend toward earlier breakup dates, as demonstrated by a negative slope with time, indicating a recent warming trend. The average change in breakup dates was 0.82 d earlier per year for the lakes in southern Wisconsin, which was more extreme than that for the northern Wisconsin lakes (0.45 d yr-1). Interannual variation in breakup dates was related to the warm phase of El Nino/Southern Oscillation (ENSO) episodes. El Nino events occurred five times during this period (1965, 1972, 1976, 1982, and 1986). Average breakup dates were significantly earlier than average (5-14 d) during the mature phase of El Nino. This variability was affected by the location of the lake: El Nino-related variation was more evident for the southern lakes than the northern lakes. This difference was caused by the average date of breakup for the southern lakes being in late March directly following the period when air temperatures were strongly related to El Nino events, whereas the average dates of breakup of the northern lakes was in mid- to late April following a period when air temperatures were not significantly related to El Nino events. Overall, the interannual and long-term patterns across Wisconsin were relatively consistent, indicating that recent warming and El Nino- related variation are regional climatic responses.

Limnology and Oceanography↗

USGS1995

Environmental factors used to subdivide the western Lake Michigan drainages into relatively homogeneous units for water-quality site selection

In 1991, the National Water-Quality Assessment (NAWQA) Program was fully implemented by the U.S. Geological Survey (USGS). The goals of the NAWQA program are to (1) provide a nationally consistent description of water-quality conditions for a large part of the Nation’s water resources; (2) define long-term trends (or lack of trends) in water quality; and (3) identify, describe, and explain, as possible, the major factors that affect the observed water-quality conditions and trends (Hirsch and others, 1988).

Michigan, Wisconsin↗

USGS1995

Water-quality and lake-stage data for Wisconsin lakes, water year 1994

The U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many yes rs, provide a data base for developing an improved understanding of the water quality of lakes\ To make these data available to interested parties outside the USGS, the data are published annually in this report series. The location of surface water-quality and lake-stage stations in Wisconsin for water year 1994 are shown in figure 1. A water year is the 12-month period from October 1 through September 30. It is designated by the calendar year in which it ends and which includes 9 of the 12 months. Thus the period October 1, 1993 through September 30, 1994, is called "water year 1994." The purpose of this report is to provide information about the physical, che-nical, and biological characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected includes measurements of lake stage and in-lake water quality. Graphs of Secchi depths, and total-phosphorus and chlorophyll-a concentrations versus time are included for lakes with two or more years of data. Descriptive information for each lake includes location of the lake, drainage area of the lake's watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published in two other volunres: "Water Resources Data-Wisconsin, 1994, St. Lawrence River Basin" (Volume 1) and "Water Resources Data-Wisconsin, 1994, Upper Mississippi River Basin" (Volume 2).

Wisconsin↗

USGS1992

Impacts of variation in planktivorous fish on abundance of daphnids: A simulation model of the Lake Mendota food web: Chapter 20

Previous chapters in this volume have outlined the goals of the Lake Mendota food web manipulation study (Rudstam et al., Ch. 12) and have reported on variations in phytoplankton and zooplankton abundances during the past 15 years (Lathrop and Carpenter, Ch. 7 and 8). Because of the long time scales inherent in such a lake management manipulation, it became imperative to attempt to predict how the lake would respond to changes in planktivorous fish abundance over time scales of several decades. We know from the past 15 years of study (Lathrop and Carpenter, Ch. 7 and 8; Magnuson and Lathrop, Ch. 11) that substantial variation of planktivorous fish, zooplankton, and phytoplankton abundances can occur the lake. Given the current stocking of piscivores, we have the potential to substantially modify the abundance of planktivorous fish and possibly shift the assemblages of phytoplankton and zooplankton beyond the ranges of those which occurred previously. In this chapter we describe the construction and use of a simulation model designed to examine how variation in plantivore abundance might impact zooplankton biomass and species composition.

Wisconsin↗

USGS1992

Lake ice records used to detect historical and future climatic changes

Historical ice records, such as freeze and breakup dates and the total duration of ice cover, can be used as a quantitative indicator of climatic change if long homogeneous records exist and if the records can be calibrated in terms of climatic changes. Lake Mendota, Wisconsin, has the longest uninterrupted ice records available for any lake in North America dating back to 1855. These records extend back prior to any reliable air temperature data in the midwestern region of the U.S. and demonstrate significant warming of approximately 1.5 °C in fall and early winter temperatures and 2.5 °C in winter and spring temperatures during the past 135 years. These changes are not completely monotonie, but rather appear as two shorter periods of climatic change in the longer record. The first change was between 1875 and 1890, when fall, winter, and spring air temperatures increased by approximately 1.5 °C. The second change, earlier ice breakup dates since 1979, was caused by a significant increase in winter and early spring air temperatures of approximately 1.3 °C. This change may be indicative of shifts in regional climatic patterns associated with global warming, possibly associated with the ‘Greenhouse Effect’. With the relationships between air temperature and freeze and break up dates, we can project how the ice cover of Lake Mendota should respond to future climatic changes. If warming occurs, the ice cover for Lake Mendota should decrease approximately 11 days per 1 °C increase. With a warming of 4 to 5 °C, years with no ice cover should occur in approximately 1 out of 15 to 30 years.

Wisconsin↗

USGS1992

Climatic changes near the Great Lakes inferred from 141 year ice records

Freeze-up and break-up dates and duration of ice cover for lakes and rivers represent an integration of weather conditions prior to the specified event(s). Changes in mean ice conditions may be used as quantitative indicators of climatic changes if long homogenous ice records are accompanied by sufficiently homogenous air temperature records to calibrate the changes in mean ice cover in terms of climatic variables. Historical ice records dating back to 1855 are available for Lake Mendota, WI (located on the southwestern side of Lake Michigan) and back to 1851 for Grand Traverse Bay, MI (located on the northeastern side of Lake Michigan). Changes in the mean ice cover of these two systems were used to describe changes in fall, winter, and spring air temperatures in the area near the Great Lakes during the past 141 years.

Michigan, Wisconsin↗