Utilization of decadal tritium variation for assessing the residence time of base flow   总被引：1，自引：0，他引：1  

Rose S 《Ground water》2007,45(3):309-317

An iterative algorithm is presented that allows the user to model the subsurface residence time of shallow ground water comprising stream base flow based on decadal scale variation of tritium concentrations. The algorithm accounts for the effects of radioactive decay, the shallow subsurface mixing of ground water with precipitation, and ground water flux. The inverse of the best-fitting modeled flux through the saturated zone is equivalent to the residence time. The data required for this model include at least two measurements of tritium in base flow for a given stream location made at least a decade apart and the long-term tritium input in precipitation for the region of interest. The model is sensitive to relatively small changes in tritium concentrations and is limited by analytic uncertainties to an accuracy of approximately +/-5 years. The algorithm was applied to stream base flow for several basins in the Piedmont Province of Georgia in which tritium concentrations were measured during the early 1990s and again in the 2000s. The model results produced highly concordant residence times for three hydrogeologically similar basins in the Upper Ocmulgee Basin in North Central Georgia. The best estimate of the average residence time for ground water comprising base flow in this Piedmont basin using this new method is between approximately 14 and 18 years. These results are generally consistent with calculations made in previous studies, and these relatively long residence times can be attributed to the storage of water in the clay soils that dominate Piedmont Province watersheds.  相似文献   

It's not just poor science--Japan's "scientific" whaling may be a human health risk too     

Parsons EC  Rose NA  Bass C  Perry C  Simmonds MP 《Marine pollution bulletin》2006,52(9):1118-1120

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D.R. Sherrod, W.E. Scott, P.H. Stauffer (eds): A volcano rekindled: the renewed eruption of Mount St. Helens, 2004–2006
USGS Prof. Paper 1750, 2009. 856 pp, plus DVD with appended data and figures, $50 printed, downloadable for free     

William I. Rose 《Bulletin of Volcanology》2010,72(3):373

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Geoffrey Boulton     

James Rose  Jane K. Hart 《Quaternary Science Reviews》2009,28(7-8):580-583

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Effects of urbanization on streamflow in the Atlanta area (Georgia,USA): a comparative hydrological approach   总被引：1，自引：0，他引：1  

Seth Rose  Norman E. Peters 《水文研究》2001,15(8):1441-1457

For the period from 1958 to 1996, streamflow characteristics of a highly urbanized watershed were compared with less‐urbanized and non‐urbanized watersheds within a 20 000 km² region in the vicinity of Atlanta, Georgia: in the Piedmont and Blue Ridge physiographic provinces of the southeastern USA. Water levels in several wells completed in surficial and crystalline‐rock aquifers were also evaluated. Data were analysed for seven US Geological Survey (USGS) stream gauges, 17 National Weather Service rain gauges, and five USGS monitoring wells. Annual runoff coefficients (RCs; runoff as a fractional percentage of precipitation) for the urban stream (Peachtree Creek) were not significantly greater than for the less‐urbanized watersheds. The RCs for some streams were similar to others and the similar streams were grouped according to location. The RCs decreased from the higher elevation and higher relief watersheds to the lower elevation and lower relief watersheds: values were 0·54 for the two Blue Ridge streams, 0·37 for the four middle Piedmont streams (near Atlanta), and 0·28 for a southern Piedmont stream. For the 25 largest stormflows, the peak flows for Peachtree Creek were 30% to 100% greater than peak flows for the other streams. The storm recession period for the urban stream was 1–2 days less than that for the other streams and the recession was characterized by a 2‐day storm recession constant that was, on average, 40 to 100% greater, i.e. streamflow decreased more rapidly than for the other streams. Baseflow recession constants ranged from 35 to 40% lower for Peachtree Creek than for the other streams; this is attributed to lower evapotranspiration losses, which result in a smaller change in groundwater storage than in the less‐urbanized watersheds. Low flow of Peachtree Creek ranged from 25 to 35% less than the other streams, possibly the result of decreased infiltration caused by the more efficient routing of stormwater and the paving of groundwater recharge areas. The timing of daily or monthly groundwater‐level fluctuations was similar annually in each well, reflecting the seasonal recharge. Although water‐level monitoring only began in the 1980s for the two urban wells, water levels displayed a notable decline compared with non‐urban wells since then; this is attributed to decreased groundwater recharge in the urban watersheds due to increased imperviousness and related rapid storm runoff. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Seasonal and event-scale variations in solute chemistry for four Sierra Nevada catchments     

JoAnn M. Holloway  Randy A. Dahlgren 《Journal of Hydrology》2001,250(1-4):106-121

Hydrobiogeochemical processes controlling stream water chemistry were examined in four small (<5 km²) catchments having contrasting bedrock lithologies in the western Sierra Nevada foothills of California. The Mediterranean climate with its cool/wet and hot/dry cycle produces strong seasonal patterns in hydrological, biological and geochemical processes. Stream water solutes fall into three general groups according to seasonal fluctuation in concentration: strong, rainy season minimum–dry season maximum (Cl⁻, SO₄²⁻, base cations); weak, rainy season minimum–dry season maximum (Si); and rainy season maximum–dry season minimum (NO₃⁻ and K⁺). Solute dynamics in soil solutions and stream water suggest that mixing of drainage waters from bedrock and soil sources regulate stream water solute concentrations. Patterns are further altered by the leaching of solutes accumulated in the soil over the summer period of desiccation and the temporal discoupling of nutrient cycles that occurs due to differences in the timing between vegetation growth (late spring) and leaching (early winter). Solute concentrations are remarkably similar between watersheds with varying bedrock types, with the exception of nitrate, sulfate and bicarbonate. Three watersheds have nitrogen-bearing metasedimentary bedrock that contributes to elevated nitrate concentrations in stream waters. Watersheds whose bedrock includes mineralized veins of sulfide and carbonate minerals similarly have greater sulfate and bicarbonate concentrations in stream water. Hydrobiogeochemical processes are highly dynamic at the seasonal and storm-event temporal scales and spatially complex at the watershed scale making management of stream water chemical composition, such as nitrate concentrations, very challenging.  相似文献   

Thermal convection of soil air on hillsides     

A. W. Rose  W. Guo 《Environmental Geology》1995,25(4):258-262

Although diffusion is usually considered to be the main transport process for volatile constituents in the unsaturated zone of soils and other surficial materials, an alternative process of thermally driven convection may be significant, especially on hillsides and over irregular bedrock. Convection in this mode is driven by buoyancy forces arising from differences in soil-air density in a temperature gradient. For bodies with sloping boundaries, the conventional Rayleigh criterion is not directly applicable, so that flow of air is possible in a wide variety of situations. Numerical simulations for several simple cases show that air convection is expected within relatively permeable materials such as sandy soils, gravel deposits, and talus on slopes.  相似文献   

Studies of volcanic ash from two recent Central American eruptions     

W. I. Rose Jr.  S. Bonis  R. E. Stoiber  M. Keller  T. Bickford 《Bulletin of Volcanology》1973,37(3):338-364

The 1971 eruptions of Cerro Negro volcano in Nicaragua and Fuego volcano in Guatemala produced ash blankets with minimum volumes of 7 × 10⁷ m³ and 6 × 10⁷ m³, respectively. Seven new chemical analyses show that ash produced by both eruptions was basaltic and similar to previously — erupted lavas of both volcanoes. Both ash blankets were sampled areally and stratigraphically before they were affected by rain. Chemical analyses of soluble materials leached from these ashes show that near the end of both eruptions the concentrations of soluble materials increased by about an order of magnitude. These changes are believed to reflect changes in the composition of eruptive gases.  相似文献   

Nuée ardente from santiaguito volcano April 1973     

W. I. Rose Jr. 《Bulletin of Volcanology》1973,37(3):365-371

The largest nuée ardente eruption of Santiaguito since November 1929, occurred April 19, 1973. The nuée descended the valley of the Rió Nimá II for a distance of about 4 km. The ash flow itself was restricted to the river bed, but the hot gas cloud devastated an area of more than 3 square kilometers extending hundreds of meters on both sides of the river bed. Because the ash cloud stopped about 2 km from the nearest habitations, there were no fatalities.  相似文献   

Cl,F, and SO2 in Central American volcanic gases     

R. E. Stoiber  W. I. Rose Jr. 《Bulletin of Volcanology》1973,37(3):454-460

The Cl, F, SO₂ contents and Cl/F and Cl/SO₄ ratios in Central American volcanic gases are examined. 10³?10⁵ tons SO₂ per day are given off during eruptions and 10² when a prominent vapor cloud persists between eruptive periods. Data regarding Cl and F and SO₄ from leachates, condensates, and incrustations are compared. Our data suggest circumpacific volcanoes are SO₂ poor relative to Cl and may be F poor although F is higher in basaltic Central American volcanoes than others.  相似文献