Dewatering well assessment for the highway drainage system at four sites in the East St. Louis area, Illinois: FY 92 Phase 9

"Prepared for the Illinois Department of Transportation.

Dewatering well assessment for the highway drainage system at five sites in the East St. Louis area, Illinois: FY 94 Phase 11

"Prepared for the Illinois Department of Transportation.

Dewatering well assessment for the highway drainage system at four sites in the East St. Louis area, Illinois: FY 93 Phase 10

"Prepared for the Illinois Department of Transportation.

Rapidly rotating plane layer convection with zonal flow

The onset of convection in a rapidly rotating layer in which a thermal wind is present is studied. Diffusive effects are included. The main motivation is from convection in planetary interiors, where thermal winds are expected due to temperature variations on the core-mantle boundary. The system admits both convective instability and baroclinic instability. We find a smooth transition between the two types of modes, and investigate where the transition region between the two types of instability occurs in parameter space. The thermal wind helps to destabilise the convective modes. Baroclinic instability can occur when the applied vertical temperature gradient is stable, and the critical Rayleigh number is then negative. Long wavelength modes are the first to become unstable. Asymptotic analysis is possible for the transition region and also for long wavelength instabilities, and the results agree well with our numerical solutions. We also investigate how the instabilities in this system relate to the classical baroclinic instability in the Eady problem. We conclude by noting that baroclinic instabilities in the Earth's core arising from heterogeneity in the lower mantle could possibly drive a dynamo even if the Earth's core were stably stratified and so not convecting.Comment: 20 pages, 7 figure

Operation of rain gauge and ground-water monitoring networks for the Imperial Valley Water Authority, year six: September 1997 - August 1998

The Illinois State Water Survey (ISWS), under contract to the Imperial Valley Water Authority (IVWA), has operated a network of rain gauges in Mason and Tazewell Counties since August 1992. The ISWS also established a network of ground-water observation wells in the Mason-Tazewell area. The networks are located in the most heavily irrigated region of the state. Ground water in various aquifers are the major source of the irrigation and domestic water supplies in the region. Recent extreme weather events (e.g., the drought of 1988 and the great flood of 1993) resulted in large fluctuations of the ground-water levels in the Imperial Valley area. The purpose of the rain gauge network and the ground-water observation well network is to collect a long-term series of data to determine the rate of ground-water drawdown in dry periods and during the growing season, and the rate at which the aquifers recharge. Precipitation is recorded for each storm that traverses the Imperial Valley, and ground-water levels at the 13 observation wells are measured the first of each month. The database from these networks consists of 6 years of precipitation data and 4 years of ground-water observations. At the beginning of the ground-water observations in 1995, the water levels were at the highest in the four years of observation. These high ground-water levels were the result of the very wet 1992-1995 period when annual precipitation was above the 30-year normals at both Havana and Mason City. From September 1995-August 1997 precipitation in the region was below the 30-year normal. The 1997-1998 observation year had rainfall above the 30-year normal. Ground-water levels in the observation wells mirrored these rainfall patterns, showing a general downward trend during the dry years and a recovery in the wet 1997-1998 year. Seasonal increases in the ground-water levels were observed at most wells during the late spring and early summer, followed by decreases in August-November ground water levels. Analysis indicates that the ground-water levels are affected by both the precipitation in the Imperial Valley area and the Illinois River stages. The observation wells closest to the Illinois River show an increase in water levels whenever the river stage is high. Generally, the water levels in the wells correlate best with precipitation and Illinois River stages one to two months before the water levels are measured, i.e., the June ground-water levels are most highly correlated with the Illinois River stage or precipitation that occurs in either April or May. The analyses conducted indicate the need for continued operation of both networks due to inconsistencies associated with ground-water levels, precipitation, and the Illinois River stage. For instance, the Mason-Tazwell observation well number 2 (MTOW-2) is located near the center of Mason County well away from the Illinois River, but it has an equal correlation with the Illinois River stage and the precipitation in the area. Additional analysis needs to be undertaken to explain this unusual finding

Triply Differential Single Ionization of Argon: Charge Effects for Positron and Electron Impact

Triply differential single ionization of Ar by 200 eV positron and electron impact is measured and calculated. For an unequivocal test of kinematic differences, fully differential ejected electron angular distributions are measured using the same experimental apparatus and conditions for both positron and electron impact. The binary/recoil intensity ratios are shown to significantly differ for the two projectiles. These data are used to test theoretical calculations

Resource Partitioning in Summer by Salmonids in South-Central Lake Ontario

During the summers of 1981 and 1982, we studied resource partitioning by stocked lake trout Salvelinus namaycush, brown trout Salmo trutta, and chinook salmon Oncorhynchus tshawytscha by fishing vertical gill nets at six distances from shore in south-central Lake Ontario. The nets were set at depths of approximately 15-45 m (nearshore stations,offshore) and more than 55 m (offshore stations, 4-24 km offshore). Salmonids were concentrated near shore, where they partitioned available habitat and, thus, food resources. Horizontal habitat was partitioned with respect to distance from shore; vertical habitat was partitioned in relation to temperature and the thermocline. Salmonids foraged for the most available prey items within their habitat. Overlaps in both food use and horizontal habitat use were inversely related to overlap in use of vertical habitat. There was increased habitat separation between sexes for those species caught farther from shore. At the salmonid stocking and prey density levels existing during our study, lake trout, brown trout, and chinook salmon appeared to partition resources and minimize deleterious trophic interactions during thermal stratification

Dewatering well assessment for the highway drainage system at five sites in the East St. Louis area, Illinois: FY 95 Phase 12

"Prepared for the Illinois Department of Transportation.

Public groundwater supplies in Wabash county

Cover title."ISWS/BUL-60(31)/84."Enumeration continues from preceding title