Transient analysis of the source of water to wells: Cape Cod, Massachusetts     

Masterson JP  Walter DA  LeBlanc DR 《Ground water》2004,42(1):126-134

A transient flow modeling analysis for potential public-supply wells on western Cape Cod, Massachusetts, demonstrates the difference between transient and steady-state recharge areas can have important implications for wellhead protection. An example of a single pumping well illustrates that commonly used steady-state time-related capture areas do not represent the recharge area and travel times of water being pumped from the well until sufficient time has elapsed for steady-state flow conditions to be established. Until that time, transient recharge areas are needed to account for the portion of water discharging from the well that entered the aquifer before pumping started. An example of two pumping wells demonstrates the same area at the water table cannot supply water to more than one well under steady-state flow conditions. Transient recharge areas to multiple wells can overlap, however, until steady-state flow conditions are established. The same area can, therefore, be a source of water to more than one well during early pumping times, and the water pumped from a given well may derive from source areas, including contaminated areas, that do not lie within the well's steady-state recharge area.  相似文献   

Injection experiments and thermal recovery in corehole OH-1, Lake City,California     

Jason?R.?McKennaEmail author  Walter?R.?Benoit  Colin?B.?Goranson  David?D.?Blackwell 《Natural Resources Research》2004,13(4):241-253

Two injection tests, shallow and deep, followed by repeated temperature logging were performed in the Lake City, California OH-1 corehole, to delineate permeable zones, investigate the permeability of rocks adjacent to the wellbore, and to test the validity of maximum-reading thermometer (MRT) measurements collected during the drilling process that show lower than static temperatures above a depth of 2100 ft and significantly higher than static temperatures below a depth of about 2500 ft. The tests confirmed several permeable zones in OH-1. At about 300 ft, there is a strong zone of lateral flow, and at 947 ft there is a major outflow zone for injected fluid. Two other possible permeable flow zones were detected from the thermal recovery logs: one at about 1500 ft and another at about 2300 ft. The 2300 ft permeable zone seems to be an inflow zone, and the source of a probable downflow responsible for cooling the wellbore below about 2500 ft. The hotter MRT data obtained during drilling may be reconciled with the significantly lower static temperature logs if downflow from about 2300 ft is present.  相似文献   

Die Beulen im deutschen Saxonikum     

Walter Carlé 《International Journal of Earth Sciences》1939,30(7-8):795-799

Ohne ZusammenfassungIm deutschen Saxonikum findet man noch eine andere Art von Beulen, deren Antriebskraft nicht das Salz ist, sondern das Magma zu sein scheint. Es ist da gleichermaßen an die süddeutschen Schilde und Becken G.Wagners (1929), an die vonElberskirch (1937) untersuchte Triasbucht von Trier und an die von H.Cloos erwähnte Bucht von Kissingen (1939, S. 472) zu denken. Diese den mittelrussischen Wällen und einem Teil der nordamerikanischen Uplifts artgleichen Gebilde gehorchen anderen Gesetzen. Sie leiten über zu den ganz großen Einheiten der Erdkruste, welche kürzlich in dieser Zeitschrift aus der Feder von H.Cloos eine umfassende Darstellung erfahren haben.  相似文献   

Beiträge zur Entwicklung der Kriegsgeologie     

Major a. D. Dr. Walter Kranz 《International Journal of Earth Sciences》1934,25(3):194-201

Ohne ZusammenfassungTeil I (Einleitung) und II (England) vgl. Geol. Rundschau,11, 1920, S. 329–349.  相似文献   

Neue Aufschlüsse     

Walter Carle 《International Journal of Earth Sciences》1936,27(6):499-499

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Climate variability and pelagic fisheries in northern Chile   总被引：5，自引：0，他引：5  

E. Yez  M. A. Barbieri  C. Silva  K. Nieto  F. Espíndola 《Progress in Oceanography》2001,49(1-4)

A time series analysis of long-term climate variability in northern Chile (18°21′–24°00′S) shows anomalies associated with the El Niño events and the longer warm period observed since 1976, followed by a cooling trend since mid 1980s. The succession of pelagic fisheries, anchovy (Engraulis ringens) and sardine (Sardinops sagax), occurring in this fishing zone was analyzed taking into account the landings, the CPUE abundance index, the fishing effort, and the environmental variables. The anchovy production model is a negative linear function of fishing effort and turbulence. For sardine, the production model is a negative linear function of fishing effort and a quadratic function of the sea surface temperature.An analysis of the relationship between recruitment, adult biomass and the environment shows that the annual recruitment of anchovy increases with turbulence intensity until wind speed reaches a value of 5.46 m s⁻¹, decreasing for higher values. For sardine, the recruitment increases with turbulence intensity until 5.63 m s⁻¹, stabilizing thereafter.It is deduced that the climatic variations associated to the El Niño events affect the abundance of coastal pelagic fishes, without forgetting the most likely effects upon its distribution and the fishing effort. However, it is the long-term variability that mainly affects the fishing activity.  相似文献   

Temporal and geographic variability of sardine maturity at length in the northeastern Atlantic and the western Mediterranean   总被引：6，自引：0，他引：6  

Silva  A.; Santos  M.B.; Caneco  B.; Pestana  G.; Porteiro  C.; Carrera  P.; Stratoudakis  Y. 《ICES Journal of Marine Science》2006,63(4):663-676

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Population genetics and evolutionary demography of Ucides cordatus (Decapoda: Ocypodidae)     

José F. Oliveira-Neto  Marcio R. Pie  Walter A. Boeger  Antonio Ostrensky  & Rafael A. Baggio 《Marine Ecology》2007,28(4):460-469

Variation in a fragment of the mitochondrial control region was investigated to assess the population history of the mangrove land crab, Ucides cordatus L., based on 100 individuals from five locations throughout the Brazilian coast. There was considerable variability in the studied fragment, with every individual showing a distinct haplotype. When regions of ambiguous alignment were removed, 90 haplotypes were still recognized, of which only 1 was shared among locations. There was no statistically significant evidence for geographical structure in the pattern of genetic variability based on a nested clade analysis, even though the geographical distances among the farthest collection sites exceeded 3000 km. Moreover, the mismatch distribution of pairwise differences showed a smooth unimodal distribution that is consistent with a recent population expansion of U. cordatus, either when each location was analysed in isolation or when all samples were combined. Interestingly, the estimates for the duration of such expansion vary latitudinally, suggesting that the expansion of the population of U. cordatus proceeded in a southward direction. These results indicate a possible relationship between the growth in the population of the mangrove land crab and the dynamics of mangrove ecosystems during the Quaternary.  相似文献   

A methodology for defining homogeneous water bodies in estuaries – Application to the transitional systems of the EU Water Framework Directive     

J.G. Ferreira  A.M. Nobre  T.C. Simas  M.C. Silva  A. Newton  S.B. Bricker  W.J. Wolff  P.E. Stacey  A. Sequeira 《Estuarine, Coastal and Shelf Science》2006,66(3-4):468-482

A methodology is developed and tested for division of estuarine and coastal systems into water bodies for monitoring and management purposes. This division is often implicit in the choice of sampling stations and in pollution abatement measures applied to different locations – it is now an explicit requirement of European Union Directive 2000/60/EC (Water Framework Directive) and recommended by United States Agencies such as EPA and NOAA. The approach considers both natural characteristics and the human dimension, by means of a stepwise methodology, which considers, on the one hand, morphology and salinity distribution, and, on the other, appropriate indicators of pressure and state. In the present application, nitrogen and phosphorus loading was used as the pressure component and chlorophyll a and dissolved oxygen as indicators of state. The criteria for system division were defined based on (1) an adimensional shape factor and salinity classes for the natural component; and (2) a normalised pressure index and (ASSETS) eutrophication symptom classes for the human dimension. Water quality databases and GIS were used to develop spatial distributions for the various components, and the results were aggregated into a final water body division, using tidal excursion as a “common sense” test. The methodology was applied to three well-studied systems in Portugal, a tubular estuary (Mondego), a wide lagunal estuary (Sado) and a coastal barrier island system (Ria Formosa). Although a final definition of water bodies will usually be a policy decision, this type of approach for the division of coastal systems into management units scientifically informs the decision-making process.  相似文献   

Occurrence and consumption of seabirds scavenging on shrimp trawler discards in the Wadden Sea   总被引：1，自引：0，他引：1  

Walter  U.; Becker  P. H. 《ICES Journal of Marine Science》1997,54(4):684-694

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