Publications

An extended Kalman filter was developed to automate the real-time estimation of ice-affected streamflow on the basis of routine measurements of stream stage and air temperature and on the relation between stage and streamflow during open-water (ice-free) conditions. The filter accommodates three dynamic modes of ice effects: sudden formation/ablation, stable ice conditions, and eventual eliminatio

Water resources data for the 1997 water year for Minnesota consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground water. This volume contains discharge records for 101 stream-gaging stations; stage and contents for 13 lakes and reservoirs; water quality for 28 stream-gaging stati

The statewide average precipitation of 31.79 inches for the 1997 water year was the same as the normal annual precipitation of 31.79 inches for water years 1961-90. Average precipitation values ranged from 78 percent of normal at Mauston 1 SE WWTP weather station in central Wisconsin to 139 percent of normal at Menomonie WWTP weather station in west central Wisconsin (Matt Menne, Acting State Clim

Ground-water contamination by crude oil, and other petroleum-based liquids, is a widespread problem. An average of 83 crude-oil spills occurred per year during 1994-96 in the United States, each spilling about 50,000 barrels of crude oil (U.S. Office of Pipeline Safety, electronic commun., 1997). An understanding of the fate of organic contaminants (such as oil and gasoline) in the subsurface is n

Wisconsin's water-monitoring network is in danger of losing critical ground-water, surface-water, and water-quality monitoring stations. Since 1995, the ground-water network has decreased by 43 observation wells, the surface-water network by 7 stations, and the surface-water- quality network by 30 stations. Reductions in Wisconsin's water-monitoring network could cause serious risk to the resident

Water resources data for the 1997 water year for Michigan consists of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of groundwater wells. This report contains discharge records for 146 streamflow-gaging stations; stage only records for 1 stream-gaging station and 20 lake-gaging stations; sta

Results of measurements of light penetration at sites in Lake Houston near Houston, Texas, indicate that light-extinction coefficients during 1989– 90 range from about 2.49 to 7.93 meters-1 and euphotic zone depth ranges from about 0.61 to 1.85 meters. The coefficients are largest near the inflow site of West Fork San Jacinto River (upstream) and decrease slightly toward the dam (downstream). Tota

Water-quality and geohydrologic data were collected between September 1993 and September 1994, from 56 wells and 2 springs, in two agricultural areas in the Western Lake Michigan Drainages study unit of the National-Water Quality Assessment Program. These data were used to study the effects of land use and geohydrology on shallow ground-water quality. Water samples from each well and spring were a

Ground-water-quality samples were collected for the intensive data-collection phase of the Red River of the P Torth Basin study unit, one of 60 study units of the National Water Quality Assessment (NAWQA) Program throughout the United States. The sampling protocols used were designed for the NAWQA Program. The protocols include sampling equipment, cleaning procedures, sample-collection methods, an

The study area of the South-Central Texas study unit of the National Water-Quality Assessment Program comprises the Edwards aquifer in the San Antonio region and its catchment area. The first phase of the assessment includes evaluation of existing water-quality data for surface water and ground water, including volatile organic compounds, to determine the scope of planned monitoring. Most analyses

During 1993-95, the agriculture on two sandy, surficial aquifers in the Red River of the North Basin affected the quality of shallow ground water in each aquifer differently. The Sheyenne Delta aquifer, in the western part of the basin, had land-use, hydrogeological, and rainfall characteristics that allowed few agricultural chemicals to reach or remain in the shallow ground water. The Otter Tail

A steady-state model of pesticide leaching through the unsaturated zone was used with readily available hydrologic, lithologic, and pesticide characteristics to estimate the vulnerability of the near-surface aquifer to atrazine contamination from non-point sources in Kent County, Michigan. The modelcomputed fraction of atrazine remaining at the water table, RM, was used as the vulnerability criter