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Mental and behavioral health conditions among schoolaged children, including substance use disorders and overall emotional well-being, are a public health concern in the United States. Timely data on seasonal patterns in child and adolescent conditions can guide optimal timing of prevention and intervention strategies. CDC examined emergency department (ED) visit data from the National Syndromic Surveillance Program for 25 distinct conditions during January 2018-June 2023 among U.S. children and adolescents aged 5-17 years, stratified by age group. Each year, during 2018-2023, among persons aged 10-14 and 15-17 years, the number and proportion of weekly ED visits for eight conditions increased in the fall school semester and remained elevated throughout the spring semester; ED visits were up to twice as high during school semesters compared with the summer period. Among children aged 5-9 years, the number and proportion of visits increased for five mental and behavioral health conditions. Seasonal increases in ED visits for some conditions among school-aged children warrant enhanced awareness about mental distress symptoms and the challenges and stressors in the school environment. Systemic changes that prioritize protective factors (e.g., physical activity; nutrition; sleep; social, community, or faith-based support; and inclusive school and community environments) and incorporate preparedness for increases in conditions during back-to-school planning might improve child and adolescent mental health. [ABSTRACT FROM AUTHOR]

The flow of terrestrial groundwater to the sea is an important natural component of the hydrological cycle. This process, however, does not explain the large volumes of low-salinity groundwater that are found below continental shelves. There is mounting evidence for the global occurrence of offshore fresh and brackish groundwater reserves. The potential use of these non-renewable reserves as a freshwater resource provides a clear incentive for future research. But the scope for continental shelf hydrogeology is broader and we envisage that it can contribute to the advancement of other scientific disciplines, in particular sedimentology and marine geochemistry., Continental shelves are the submerged fringes of the continents and harbour important aquifers beneath the sea floor. Because the shelves are at present covered by sea water, hydrogeology--a scientific discipline [...]

In this study, we have integrated a suite of Holocene paleoclimatic proxies with mathematical modeling in an attempt to obtain a comprehensive picture of how watersheds respond to past climate change. A three-dimensional surface-water-groundwater model was developed to assess the effects of mid-Holocene climate change on water resources within the Crow Wing Watershed, Upper Mississippi Basin in north central Minnesota. The model was first calibrated to a 50 yr historical record of average annual surface-water discharge, monthly ground-water levels, and lake-level fluctuations. The model was able to reproduce reasonably well long-term historical records (1949-1999) of water-table and lake-level fluctuations across the watershed as well as stream discharge near the watershed outlet. The calibrated model was then used to reproduce paleo-groundwater and lake levels using climate reconstructions based on pollen-transfer functions from Williams Lake just outside the watershed. Computed declines in mid-Holocene lake levels for two lakes at opposite ends of the watershed were between 6 and 18 m. Simulated streamflow near the outlet of the watershed decreased to 70% of modern average annual discharge after ~200 yr. The area covered by wetlands for the entire watershed was reduced by ~16%. The mid-Holocene hydrologic changes indicated by these model results and corroborated by several lake-core records across the Crow Wing Watershed may serve as a useful proxy of the hydrologic response to future warm, dry climatic forecasts (ca. 2050) made by some atmospheric general-circulation models for the glaciated Midwestern United States. Keywords: paleohydrology, climate change, hydrogeology, modeling, paleolimnology.

Salinity data from the Atlantic continental shelf off New England indicate that the freshwater/saltwater interface is far out of equilibrium with modern sea-level conditions. More than 150 km offshore of Long Island, New York, aquifer salinity levels are less than 5 parts per thousand (5 ppt). Salinity levels within confining units beneath Nantucket Island, Massachusetts, are 30%-70% of seawater levels and exhibit a parabolic profile consistent with ongoing vertical diffusion. Here, we evaluate two fluid-flow-inducing mechanisms that could explain the apparent flushing of these coastal-plain aquifers: (1) meteoric recharge during Pleistocene sea-level low-stands, and (2) subglacial recharge from the Laurentide Ice Sheet. Analytical models of vertical solute diffusion for the Nantucket confining units suggest that flushing of aquifers beneath Nantucket began in the late Pleistocene between ca. 195 and 21 ka; the models assume a diffusion coefficient of 3.0 x [10.sup.-11] [m.sup.2]/s. Cross-sectional numerical models of variable-density groundwater flow, heat, and solute transport could not reproduce the relatively low-salinity groundwaters observed off Long Island by applying boundary conditions consistent with Pleistocene sea-level fluctuations. Observed salinity conditions were most closely matched in the models by also including the effects of sub-glacial recharge from the Laurentide Ice Sheet and allowing groundwater to discharge from Miocene aquifers along submarine canyons near the continental slope. Simulated recharge induced by Laurentide Ice Sheet meltwater was probably short lived but, on average, about two to ten times greater than modern subaerial levels. A sensitivity analysis performed using our cross-sectional model suggests that a narrow range of hydrologic conditions can drive fresh water long distances offshore across the continental shelf. Keywords: hydrogeology, glaciology, salinity, paleohydrology.

Introduction In the United States, the concept of wellhead protection can be traced back as early as 1612 to the Jamestown, Virginia, settlement where laws restricted activities within 30 m [...]

Introduction During the past two decades, demands on Nantucket Islands' ground water resources have increased dramatically. Between 1981 and 1997, pumping records from the town of Nantucket's municipal wellfield indicate [...]

Abstract Agricultural irrigation has a substantial impact on water quantity and quality in the lower Arkansas River valley of southeastern Colorado. A two-dimensional flow and solute transport model was used [...]

Two-dimensional finite element models of coupled sediment compaction, variable-density ground-water flow, and conductive/convective heat transfer are used in this study to quantify basin hydrodynamics during the initial and flexural stages of continental rifting. The analysis also incorporates a two-stage stretching/cooling geodynamic model of the thermomechanical evolution of the lithosphere underlying the rift in order to specify geologically relevant boundary conditions for basin subsidence and basal heat flow. A sensitivity study is made using the model to explore the controls of both permeability and water table configuration in determining the dominant fluid flow drive (compaction, density, or topography) during basin evolution. The sensitivity analysis incorporates hydrologic conditions and rock properties representative of many extensional terrains. Assuming that rift basin subsidence and basal heat flow can be represented by the geodynamic model, two distinct ground-water flow systems evolve within continental rifts during basin evolution, During the initial (stretching) phase of rifting, subsidence is accommodated by fault block motion, and a topography-driven ground-water flow system develops within the permeable alluvial-fan deposits. Within the less permeable lacustrine facies located in the center of the basin, compaction-driven ground-water flow dominates. Here, the compacting lacustrine sediments focus pore fluids laterally from the basin center into the alluvial-fan fan deposits due to the relatively large permeability contrast between the two depositional environments. Thermal anomalies resulting from convective heat transfer are restricted to alluvial-fan facies near the basin-framing fault During the thermal cooling (flexural) stage of basin development, laterally extensive onlap facies are deposited, and density-driven ground-water flow dominates in the permeable alluvial-fan deposits, while compaction-driven flow continues within the lacustrine and onlap facies. The presence of a permeable aquifer within the onlap fades resulted in long-range fluid transport to the edge of the basin. During both stages of basin evolution, ground-water velocities varied from 10-5 to 10-1 m/yr between the lacustrine and alluvial-fan deposits, respectively. The observed presence of ore mineralization within alluvial-fan deposits of some continental-rift systems, such as the Cretaceous Rift Basin of Angola, supports the findings of this study.