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71.
The concept of using the atmospheric water balance technique in the study of the hydrology of large (greater than 105km2) river basins is described. The atmospheric water balance technique consists of determining the spacial and time distributions and fluxes of water vapor through the atmospheric volume overlying the basin. The quantity precipitation minus evaporation at the earth's surface is determined as a residual of the computation. A review of the results of various experiments employing this technique is provided. The incorporation of the technique in a study of the hydrology of a large river basin is demonstrated by showing the results of a study of the hydrometeorology of the Upper Colorado River Basin. The example covers the study of eleven winter seasons, November through April, 1957–1968. The seasonal accumulation of water over the basin as determined by the atmospheric water balance is highly correlated with annual runoff. Correlation coefficient r = .8. The daily evaporation rate during dry days varies by a factor of two over the winter season, and is shown to be related to the incoming solar radiation intensity.  相似文献   
72.
Within the past decade, reproductive and health disorders have been reported to occur in unique populations of Atlantic stingrays (Dasyatis sabina) inhabiting certain components of Florida's St. Johns River. Since these irregularities are consistent with the alleged effects of organochlorine (OC) contaminant exposure in other Florida wildlife, the goal of this study was to examine possible associations between OC concentrations and reproduction and/or immune function in stingrays from this river system. Liver concentrations of 30 OC pesticides/pesticide metabolites and total polychlorinated biphenyls (PCBs) were measured and compared in D. sabina collected from four central Florida lakes of the St. Johns River: Lake George, Lake Harney, Lake Jesup, and Lake Monroe. Reproductive biology, serum testosterone and 17beta-estradiol concentrations, and circulating white blood cell counts were examined and compared in stingrays from lakes that were determined to contain low (Lake George), intermediate (Lake Monroe), and high (Lake Jesup) levels of pesticide contamination, based on the results of liver OC assessments. Successful breeding occurred in Lake Jesup stingrays, indicating that the degree of OC accumulation in these animals is not high enough to cause reproductive impairment. However, elevated serum steroid concentrations and white blood cell counts were observed in Lake Jesup stingrays, suggesting that endocrine and immune function may be altered in these animals due to OC exposure and/or other, as yet unknown, ecological factors. Inconsistencies in the reproductive success of Lake Monroe stingrays were observed, confirming earlier reports of reproductive complications in this sub-population. Based on these findings, previous occurrences of reproductive failure in St. Johns River stingrays may be due to environmental factors other than OC exposure.  相似文献   
73.
The U.S. Department of Defense-approved activities conducted at the Utah Test and Training Range (UTTR) include both operational readiness test firing of intercontinental ballistic missile (ICBM) motors, as well as the destruction of obsolete or otherwise unusable ICBM motors through open burn/open detonation (OB/OD). Within the Utah Division of Air Quality, these activities have been identified as having the potential to generate unacceptable noise levels, as well as significant amounts of volatile organic compounds (VOCs). Hill Air Force Base, UT, has completed a series of field tests at the UTTR in which sound-monitoring surveillance of OB/OD activities was conducted to validate the Sound Intensity Prediction System (SIPS) model. Using results generated by the SIPS model to support the decision to detonate, the UTTR successfully disposed of missile motors having an aggregate net explosive weight (NEW) of 81,374 lb without generating adverse noise levels within populated areas. In conjunction with collecting noise-monitoring data, air emissions were collected to support the development of air emission factors for both static missile motor firings and OB/OD activities. Through the installation of 15 ground-based air samplers, the generation of combustion-fixed gases, VOCs, and chlorides was monitored during the 81,374-lb NEW detonation event. Comparison of field measurements to predictions generated from the US Navy energetic combustion pollutant formation model, POLU4WN, indicated that, as the detonation fire ball expanded, organic compounds, as well as CO, continued to oxidize as the combustion gases mixed with ambient air. VOC analysis of air samplers confirmed the presence of chloromethane, vinyl chloride, benzene, toluene, and 2-methyl-1-propene. Qualitative chloride analysis indicated that gaseous HCl was generated at low concentrations, if at all.  相似文献   
74.
All U.S. Department of Defense (DoD) facilities are required under Executive Order (EO) 13148, "Greening the Government through Leadership in Environmental Management," to establish quality-based environmental management systems (EMSs) that support environmental decision-making and verification of continuous environmental improvement by December 31, 2005. Compliance with EO 13148 as well as other federal, state, and local environmental regulations places a significant information management burden on DoD facilities. Cost-effective management of environmental data compels DoD facilities to establish robust database systems that not only address the complex and multifaceted environmental monitoring, record-keeping, and reporting requirements demanded by these rules but enable environmental management decision-makers to gauge improvements in environmental performance. The Enterprise Environmental Safety and Occupational Health Management Information System (EESOH-MIS) is a new electronic database developed by the U.S. Air Force to manage both the data needs associated with regulatory compliance programs across its facilities as well as the non-regulatory environmental information that supports installation business practices. The U.S. Air Force, which has adopted the Plan-Do-Check-Act methodology as the EMS standard that it will employ to address EO 13148 requirements.  相似文献   
75.
The Singular Value Decomposition (SVD) approach to stability analysis of the Chemical Mass Balance (CMB) receptor model is extended to incorporate uncertainties in both source and ambient compositions. SVD is applied to determine the improved precision with which the impact of residential wood smoke can be estimated by including methyl chloride in a CMB analysis. Wood smoke impacts in Hillsboro and Medford, Oregon, are examined. The results indicate that including methyl chloride will dramatically improve the precision of estimating wood smoke impacts for Medford, while estimates for Hillsboro are changed to a much lesser extent. This result is reasonable since the Medford airshed includes many industrial sources of particulate matter with chemical compositions similar to residential wood smoke, while Hillsboro is predominantly a residential community. The precision improvements estimated by SVD are verified by CMB analysis of a series of ambient samples collected in Hillsboro. Finally, the applicability of SVD as a receptor model study design tool is discussed.  相似文献   
76.
77.
ABSTRACT: Evaporative heat loss is an essential component of any heat budget used for the modeling of lake water temperatures. Seven evaporative heat loss equations were tested in a year-round, physically-based temperature and dissolved oxygen model for lakes. Deciding which equation to choose for use in the year-round model was based on the goodness of fit of the simulated vs. measured surface temperatures, which were taken at a depth of 1 m below the water surface. An equation which includes free and forced convection components and which was previously used for cooling ponds gave the best fit between temperature simulations and measurements.  相似文献   
78.
The percentage of the cross-sectional area of two objects (e.g., vehicles, hikers, or animals) that can be seen from each of their locations in a forested area is generally not the same. There is a directionality to the visibility between them. This is due to the relative positions and sizes of the vegetation and other view-blocking features between the objects. An analytical technique has been developed to help understand bidirectional visibility. Its use entails the construction of a visibility diagram containing the basic visibility information between observers in a given setting. An example is presented showing the use of the visibility diagram to determine visibility between two moving observers in a forested environment. The diagram is also used to determine the differences in the percentage each observer has of the other's visible cross-sectional area (bidirectional visibility). A discussion of the application of the technique in the planning or development of new facilities, as well as in forest and wildlife management, is provided.  相似文献   
79.
Summary The energetic cost of guarding estrous females has been assumed to be a potentially major factor in limiting the duration of male consortships in a number of polygamous species. This issue has been examined in the present study by assessing changes in the usual activity budgets of 13 male and 20 female yellow baboons which occurred during their consortships.The percent of time adult males spent feeding was strongly related to their agonistic rank: Higher-ranking males fed proportionately more than lower-ranking males while not in consort, and they showed a relatively greater decrease in feeding time during consortships.The proportion of time females spent feeding was related to their agonistic rank and (to a lesser degree) to their parity. Higher-ranking females fed more than lower-ranking females outside of consortships, and showed a relatively greater decrease in time spent feeding while in consort. Nulliparous females tended to feed more than parous females while not in consort; during consortships, the feeding time of nulliparous females decreased, while that of parous females increased slightly.The activity of male and female consort partners was most coordinated during the fertile cycle stage of the female partner, and least coordinated once the female had passed the fertile stage.Although reductions in feeding time during consortships were generally much more pronounced in males than in females, neither males nor females appeared to attain the undisturbed optimal feeding level for their sex while in consort.  相似文献   
80.
A nested multiplex polymerase chain reaction (PCR) assay has been developed that allows the discrimination between six bivalve larvae common to Danish coastal waters (Cerastoderma edule, Macoma balthica, Mytilus edulis, Spisula subtruncata, Ensis americanus and members of the order Myoida). This assay involves the simultaneous use of a pair of general universally targeted 18S rRNA gene primers, five specific 18S rRNA gene targeted oligonucleotide primers internal (nested) to the universal primer pair and one species-specific primer that is not nested (Mya). The specificity of each primer was evaluated in silico, empirically, and verified further by sequencing of amplification products from single larvae collected from plankton samples. Identification of individually isolated bivalve larvae from plankton samples was based on the size of the PCR product produced by the specific primers after visualisation by agarose gel electrophoresis. Preliminary studies indicated that this method was suitable for use with freshly collected and preserved larvae, and is therefore suitable for field application.Communicated by M. Kühl, Helsingør  相似文献   
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