Maps showing altitude of the potentiometric surface and changes in water levels in the aquifer in the Sparta and Memphis Sands in eastern Arkansas, spring 1985

Much of the southwestern part of Ontario between Lake Huron and Lake Erie has a thin freshwater aquifer overlain by an aquitard of Late Pleistocene clayey glaciolacustrine deposits and underlain by a thick Devonian shale aquitard. In a large area east of the St. Clair River, where the Quaternary aquitard is 30-50 m thick, groundwater of Pleistocene origin (identified by 18O and 2H signature) occurs in the aquifer and in the bottom part of the Quaternary aquitard. Numerous piezometer nests in the aquitard show a downward hydraulic gradient with depth. In some areas, the aquitard has downward gradients only in the upper part and upward gradient in the lower part, indicating a transient condition. The piezometer nests in the clayey aquitard also show an increase in Cl- concentration with depth. Long-term piezometer monitoring at two sites show a major shift in the aquitard hydraulic gradient since 1983 and a large rise in head in the underlying aquifer. Analyses of initial aquifer water levels, reported in well drilling records, indicate a large decline in the potentiometric surface of the aquifer between the 1940's and the 1970's followed by a recent rise in the surface in part of the region. This pattern is consistent with well drilling and water use records indicating that 7000 wells were installed in the aquifer in the three decades since 1940 and that groundwater use has greatly diminished in the past 10-15 years due to rural pipeline distribution of lake and river water. The hydraulic gradient in the aquitard is slowly adjusting to the rise in the aquifer potentiometric surface. One-dimensional solute transport modelling provides close matches to the vertical profiles of Cl- migrating upward from the aquifer since deglaciation, 15 000 - 18 000 years before present, by diffusion with little or no advection. The lack of advection indicates a near-neutral long-term hydraulic gradient. As the withdrawal rate of water from the aquifer continues to decline, it is expected that the hydraulic head in the aquitard in much of the area westward of the recharge area will continue to adjust for many decades.Key words: clay, aquitard, aquifer, water use, hydraulic gradient.

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Altitude of the potentiometric surface and changes in water levels in the Sparta-Memphis aquifer in eastern and southern Arkansas, spring 1986

10.3133/wri884042 ◽

1989 ◽

Keyword(s):

Water Levels ◽

Potentiometric Surface ◽

Memphis Aquifer

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Drilling, construction, water chemistry, water levels, and regional potentiometric surface of the upper carbonate-rock aquifer in Clark County, Nevada, 2009–2015

Scientific Investigations Map ◽

10.3133/sim3434 ◽

2019 ◽

Author(s):

Jon W. Wilson

Keyword(s):

Water Chemistry ◽

Carbonate Rock ◽

Water Levels ◽

Clark County ◽

Potentiometric Surface

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Stereological Analyses of Hepatocyte Ultrastructure Monitor Arsenic Liver Burdens

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600001896 ◽

1980 ◽

Vol 38 ◽

pp. 442-443

Author(s):

E. M. B. Sorensen ◽

R. R. Mitchell ◽

L. L. Graham

Keyword(s):

Drainage System ◽

Water Levels ◽

Ultrastructural Changes ◽

Hepatocyte Ultrastructure ◽

Lepomis Cyanellus ◽

Large Numbers ◽

Activation Data ◽

Water Analyses ◽

Municipal Lake ◽

Green Sunfish

Endemic freshwater teleosts were collected from a portion of the Navosota River drainage system which had been inadvertently contaminated with arsenic wastes from a firm manufacturing arsenical pesticides and herbicides. At the time of collection these fish were exposed to a concentration of 13.6 ppm arsenic in the water; levels ranged from 1.0 to 20.0 ppm during the four-month period prior. Scale annuli counts and prior water analyses indicated that these fish had been exposed for a lifetime. Neutron activation data showed that Lepomis cyanellus (green sunfish) had accumulated from 6.1 to 64.2 ppm arsenic in the liver, which is the major detoxification organ in arsenic poisoning. Examination of livers for ultrastructural changes revealed the presence of electron dense bodies and large numbers of autophagic vacuoles (AV) and necrotic bodies (NB) (1), as previously observed in this same species following laboratory exposures to sodium arsenate (2). In addition, abnormal lysosomes (AL), necrotic areas (NA), proliferated rough endoplasmic reticulum (RER), and fibrous bodies (FB) were observed. In order to assess whether the extent of these cellular changes was related to the concentration of arsenic in the liver, stereological measurements of the volume and surface densities of changes were compared with levels of arsenic in the livers of fish from both Municipal Lake and an area known to contain no detectable level of arsenic.

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AUTOMATIC WATER LEVEL MONITORING WITH IOT AND LPWAN

International Conference on Technics Technologies and Education ◽

10.15547/ictte.2019.02.041 ◽

2019 ◽

pp. 95-103

Author(s):

Krum Videnov ◽

Vanya Stoykova

Keyword(s):

Water Level ◽

Real Time ◽

Early Warning ◽

Water Sources ◽

Water Levels ◽

Water Level Fluctuations ◽

Level Monitoring ◽

Water Level Monitoring

Monitoring water levels of lakes, streams, rivers and other water basins is of essential importance and is a popular measurement for a number of different industries and organisations. Remote water level monitoring helps to provide an early warning feature by sending advance alerts when the water level is increased (reaches a certain threshold). The purpose of this report is to present an affordable solution for measuring water levels in water sources using IoT and LPWAN. The assembled system enables recording of water level fluctuations in real time and storing the collected data on a remote database through LoRaWAN for further processing and analysis.

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Using groundwater levels and Specific Yield to Estimate the Recharge, South of Erbil, Kurdistan Region, Iraq

Academic Journal of Nawroz University ◽

10.25007/ajnu.v7n4a289 ◽

2018 ◽

Vol 7 (4) ◽

pp. 191

Author(s):

Sherwan Sh. Qurtas

Keyword(s):

Unconfined Aquifer ◽

Middle Part ◽

Water Levels ◽

Specific Yield ◽

Aquifer System ◽

Groundwater Levels ◽

Monitoring Wells ◽

Water Table Fluctuation Method ◽

Recharge Estimation ◽

Fluctuation Method

Recharge estimation accurately is crucial to proper groundwater resource management, for the groundwater is dynamic and replenished natural resource. Usually recharge estimation depends on the; the water balance, water levels, and precipitation. This paper is studying the south-middle part of Erbil basin, with the majority of Quaternary sediments, the unconfined aquifer system is dominant, and the unsaturated zone is ranging from 15 to 50 meters, which groundwater levels response is moderate. The purpose of this study is quantification the natural recharge from precipitation. The water table fluctuation method is applied; using groundwater levels data of selected monitoring wells, neighboring meteorological station of the wells, and the specific yield of the aquifers. This method is widely used for its simplicity, scientific, realistic, and direct measurement. The accuracy depends on the how much the determination of specific yield is accurate, accuracy of the data, and the extrapolations of recession of groundwater levels curves of no rain periods. The normal annual precipitation there is 420 mm, the average recharge is 89 mm, and the average specific yield is around 0.03. The data of one water year of 2009 and 2010 has taken for some technical and accuracy reasons.

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