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11.
G. N. Rao J. N. Beck H. E. Murray D. J. Nyman 《Journal of the American Water Resources Association》1991,27(1):47-58
ABSTRACT: Specific capacity data obtained from Well Construction reports which are available from USGS offices, can provide useful estimates of tranamissivity (T), and hydraulic conductivity (K), of an aquifer. The Chicot Aquifer in Louisiana is one of the largest sources of fresh ground water in North America. Hydrologic data collected for the Chicot Aquifer indicate that specific capacity tests can be used in estimating local and regional values for T and K, if the Cooper-Jacob equation for transient flow is used with proper corrections for well loss and partial penetration. Where full scale pumping test data are scarce, specific capacity test data that are adequately distributed spatially can be used to map changes in T and K values and can be summarized statistically to indicate applicable regional values. A computer program called “TGUESS” which is available from International Ground Water Modeling Center, Holcomb Research Institute, was used in this study. The contour maps for T and K values are prepared for different well depth intervals to avoid wide variation of values. 相似文献
12.
Moths learn to associate a flower odor with a food reward after a few learning trials. Can a hungry, male moth learn to associate a sex attractant with food instead of with sex? We provided a hungry male with odors of single female sex pheromone components, of the full sex pheromone blend or of a flower odor component as cues in an appetitive learning assay. The male learned the single pheromone components just as well as the flower odor. Learning was, however, severely impaired when the full sex pheromone blend was used as conditioning stimulus. The "hard-wiring" between pheromone odor and sex thus seems to be restricted to those circumstances when the male moth experiences the full blend. 相似文献
13.
14.
Michael B. Sonnen Bill B. Dendy Kris P. Lindstrom 《Journal of the American Water Resources Association》1981,17(3):394-398
Farmers from four irrigation districts in Texas and California were questioned about water conservation practices they are now using, those they plan to adopt, and potential incentives that government might offer to induce still further water conservation on their part. While responses differed somewhat from place to place and among individual farmers, the general results were: a) farmers reported that “water conservation” is not new to them, it is something they practice regularly; b) recent innovations such as laser controlled land leveling devices have permitted some substantial water use reductions in recent years; and c) even greater incentive mechanisms that government could provide and that farmers would accept as useful incentives, such as long term low interest loans for water saving equipment, would probably not be able to reduce water use in agriculture much further than 15 percent below current levels. It is recommended nonetheless that Federal agencies and local water districts and individuals should nonetheless pursue water conservation training and education programs, demonstrations of conjunctive use and water banking opportunities for water saving, and increased loan programs for installation of water saving equipment. 相似文献
15.
Stormwater discharged from highly urbanised catchments on the southern shore of Sydney estuary, Australia, has been identified
as the primary source of contaminants responsible for ecological degradation and reduction in recreational value of the waterway.
Effective management of this pollution requires knowledge of contaminant loads associated with various stormwater flow conditions
in three highly urbanised catchments in Sydney estuary catchment. The majority (>90%) of metal (Cu, Pb and Zn) and total suspended
solid annual loads were contributed during high-flow conditions (>50 mm rainfall dayt1), whereas ≤55% of TN and ≤21% of total phosphorus were contributed to annual loading by dry weather base-flow conditions.
All flow conditions posed an in-stream ecological threat because contaminant concentrations exceeded water quality guidelines
for all analytes measured, except Pb. Irregular, temporal variability in contaminant concentrations associated with base-flow
(within day and amongst days), high-flow (amongst events) and irregular discharges indicated that contaminant contributions
in stormwater were strongly controlled by human activity in the three catchments. Significant variation in contaminant concentrations
under all flow conditions revealed unique chemical signatures for each catchment despite similarities in land uses, location
and geology amongst catchments. These characteristics indicate that assessment and management of stormwater pollution needs
to be conducted on an individual-catchment basis for highly urbanised regions of Sydney estuary catchment. 相似文献
16.
Lisa Ernoul Nicolas Beck Damien Cohez Christian Perennou Marc Thibault Loic Willm 《Journal of Environmental Planning and Management》2015,58(6):1096-1112
This study analysed 14 management plans and guidelines from a 25-year period to understand trends in conservation planning. A Rosetta Stone Analysis was used for the systematic comparison of plans and guidelines. Management plans incorporated management philosophies, management scenarios, opportunities for infrastructure, and plans for data collection by 2000. As of 2010, they incorporated ecosystem services, stakeholders’ objectives and methods for storing and analysing data. The results demonstrate the complex nature of management plans, with an important workload for site managers. Recommendations for future planning include adjustments in planning timeframes and a better identification of conservation targets from initial stages. 相似文献
17.
18.
Robin M. D. Beck 《Die Naturwissenschaften》2012,99(9):715-729
Recent molecular data strongly support the monophyly of all extant Australian and New Guinean marsupials (Eomarsupialia) to the exclusion of extant South American marsupials. This, together with available geological and fossil evidence, has been used to argue that the presence of marsupials in Australia is simply the result of a single dispersal event from South America during the latest Cretaceous or Palaeocene, without subsequent dispersals between the two continents. Here, I describe an isolated ankle bone (calcaneus) of a metatherian from the early Eocene Tingamarra Local Fauna in northeastern Australia. Strikingly, this specimen, QM F30060, lacks the ‘continuous lower ankle joint pattern’ (CLAJP), presence of which is a highly distinctive apomorphy of the marsupial clade Australidelphia, which includes Eomarsupialia, the living South American microbiotherian Dromiciops and the Tingamarran fossil marsupial Djarthia. Comparisons with a range of marsupials and stem-metatherians strongly suggest that the absence of the CLAJP in QM F30060 is plesiomorphic, and that this specimen represents the first unequivocal non-australidelphian (‘ameridelphian’) metatherian known from Australia. This interpretation is confirmed by phylogenetic analyses that place QM F30060 within (crown-group) Marsupialia, but outside Australidelphia. Based on these results, the distribution of marsupials within Gondwana cannot be explained by simply a single dispersal event from South America and Australia. Either there were multiple dispersals by marsupials (and possibly also stem-metatherians) between South America and Australia, in one or both directions, or, alternatively, there was a broadly similar metatherian fauna stretching across southern South America, Antarctica and Australia during the Late Cretaceous–early Palaeogene. 相似文献
19.
Bill Vitek 《Conservation biology》2004,18(6):1463-1464
20.
In situ treatability studies are being conducted to evaluate various in situ technologies to manage groundwater contamination at the NASA Marshall Space Flight Center in Huntsville, Alabama. The focus of these studies is to evaluate remediation options for contaminated (mostly aerobic) groundwater occurring within the basal portion of a clayey residuum called the rubble zone. The tension‐saturated media and unsaturated media lying above the rubble zone are also being treated where they make up a significant component of the contaminant mass. An in situ chemical reduction field pilot test was implemented (following bench‐scale tests) during July and August 2000. The test involved the injection of zero‐valent iron powder in slurry form, using the FeroxSM process patented by ARS Technologies, Inc. The pilot test focused on trichloroethene (TCE)‐contaminated groundwater within the rubble zone. Maximum pre‐injection concentrations of about 72,800 micrograms per liter (μg/l) were observed and no secondary sources are believed to exist beneath the area. The potential presence of unexploded ordnance forced an implementation strategy where source area injections were completed, as feasible, followed by overlapping injections in a down gradient alignment to create a permeable reactive zone for groundwater migration. Eight post‐injection rounds of groundwater performance monitoring were completed. The results are encouraging, in terms of predicted responses and decreasing trends in contaminant levels. © 2003 Wiley Periodicals, Inc. 相似文献