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1.
ABSTRACT: A national trend over the last 25 years has been to require increasing amounts of biological information on industrial waste discharges. Acquisition of this essential information frequently involves complex assessments. In order to optimize the value of information gathered and to minimize the cost of this information, it is essential that analyses of redundancy be accompanied by the determination of which groups of organisms give the most information relative to a particular problem. Studies of the effect of temperature on the fishes of the New River, Glen Lyn, Virginia, provide us with the opportunity to evaluate the redundancy of information relative to the influence of temperature on fish distribution. Information of this type will be useful in selecting groups of organisms for laboratory temperature preference and avoidance tests. It was shown that the distribution of three genera (Notropis, Micropterus, and Etheostoma) had the highest correlation with the distribution of the total fish fauna and, therefore, provided the most information relative to temperature selection of the New River ichthyofauna. The final temperature preferences of the most abundant species of Notropis and Micropterus were representative of the response of the entire fish community based on the distribution of diversity indices relative to temperature.  相似文献   

2.
A modified transient version of the Streeter-Phelps model along with the energy balance equation is employed to analyze the effects of waste heat discharge from power plants on stream water quality. Analysis is also made to examine the effects of the upstream water quality and stream velocity on the downstream DO concentration level. The resulting coupled nonlinear hyperbolic partial differential equations representing the energy, BOD and DO concentrations are solved by the method of characteristics and simulated on a digital computer. Final numerical results indicate that the allowable quantity of thermal discharge does heavily depend on the upstream quality.  相似文献   

3.
ABSTRACT: The effects of variable discharges during the summer on the dissolved oxygen (DO) content and water temperature upstream and downstream of the Conowingo Hydroelectric Power Station were investigated. The DO dynamics are controlled primarily by meteorological factors that are independent of the mode of hydrostation operation. DO stratification occurred during the summer in Conowingo Pond, but thermal stratification was not observed. The magnitude and duration of off-peak discharges including a run-of-the-river operation did not affect DO stratification in Conowingo Pond; little vertical mixing occurred. However, strong winds and/or high river flows temporarily destroyed DO stratification. The run-of-the-river operation or off-peak continuous discharge schemes did not provide better DO conditions downstream of the hydrostation than the peaking operation with intermittent off-peak releases. A statistical model predicted that a DO of 5 ppm occurs 0.6 miles downstream of the powerhouse when the natural river flow is consistently greater than 15,000 cfs and water temperature is less than 80°F. A mean daily DO of at least 4 ppm was predicted to occur over 80 percent of the time during the 92-day summer period. Farther downstream (1.3 miles from the powerhouse) a mean daily DO of at least 4 ppm was predicted to occur 90 percent of the time in summer.  相似文献   

4.
ABSTRACT. Studies were conducted to determine the distribution of fish in the New and East Rivers in relation to thermal discharges from Appalachian Power Company's fossil fuel plant at Glen Lyn, Virginia. Over 15,300 specimens representing 41 species were collected with seines, electrogear and rotenone at six sampling locations from February, 1973 to October 1973. Sampling frequency was designed to evaluate the effects of ambient temperature upon preferred temperature. Diversity indices were calculated for each location. There was a slight decrease in the diversity indices for those stations located in the thermal discharge. Condition coefficients calculated for Notropis albeolus Jordan, Notropis rubellus Aqasaiz, Notropis spilopterus Cope, Ictalurus punctatus Rafinesque, and Etheostoma blennioides Rafuesque were found to be significantly (p =.05) lower in the thermal discharge for all species tested except E. blennioides. Temperatures were plotted against frequency of capture to determine a particular species temperature selection from field data and indicated that: (1) Some species avoided high temperatures (i.e., Curnpostoma anomalum Rafuesque). (2) Some species were attracted to high temperatures (i.e., Ictalurus punctatus). (3) Some species distribution was not effected by temperatures (i.e., Notropis spilopterus).  相似文献   

5.
ABSTRACT: The time variation in the temperature distribution of a static water impoundment is predicted. The body of water is modeled as a discrete number of horizontally isothermal layers and the energy equation is solved using an implicit numerical scheme. Vertical energy transport mechanisms included are solar absorption, molecular diffusion, and convective mixing due to nocturnal turnover. The latter mechanism, called diurnal mixing, is found to have a profound effect on the stratification, particularly in the eplimnion patterns for a typical deep static impoundment.  相似文献   

6.
he influence of woody vegetation on the reliability of a sandy levee was investigated using field data in seepage and slope stability analyses. Field data were collected from selected sites within a 10-km segment of a channel levee on the Sacramento River near Elkhorn, California. Root architecture and distribution were determined using the profile-wall method in which root cross sections were exposed in the vertical wall of an excavated trench. Transects running both parallel and perpendicular to the crest of the levee were excavated at six sites. Each site was dominated by different plant species: five sites were adjacent to trees or woody shrubs, while one supported only herbaceous growth. Lateral plant roots were primarily restricted to, and modified, the near-surface soil horizons to a depth of approximately 1 meter. Root area ratios (RARs) did not exceed 2.02 percent and generally decreased exponentially with depth. At depths greater than 20 cm, mean RARs for sites dominated by wood species were not significantly different from the mean RAB for the herbaceous site. No open voids clearly attributable to plant roots were observed. Roots reinforced the levee soil and increased shear resistance in a measurable manner. Infinite slope and circular arc stability analyses were performed on the landward and riverward slopes under different hydraulic loading conditions. Infinite slope analyses indicated increasing root area ratio from 0.01 percent to 1 percent increased the factor of safety from less than one to more than seven. Circular arc analyses indicated that even the lower measured root concentrations sufficed to increase safety factors for arcs with maximum depths of about 1 m from less than one to about 1.2. Our findings suggest that allowing woody shrubs and small trees on levees would provide environmental benefits and would enhance structural integrity without the hazards associated with large trees such as wind-throwing.  相似文献   

7.
ABSTRACT: Sustained interest in and concern about the health status of the aquatic environment has resulted in extensive research focused on (1) effects of pollution on survival, growth, and reproduction of resource species at all life stages; (2) diseases of fish and shellfish, as they may be related to pollution and as they may serve as indicators of environmental stress; and (3) contaminant body burdens in fish and shellfish - their effects on the aquatic animals and their potential effects on humans. Effects, lethal and sublethal, of pollutants on life history stages of fish and shellfish have been documented, as have impacts on local stocks in badly degraded habitats, but as yet there has been no adequate quantitative demonstration of effects on entire aquatic species - probably because of the difficulty in sorting out relative effects of the many environmental factors that influence abundance. Sublethal effects, especially those that result in disease, have been examined intensively, and some diseases and disease syndromes have been associated statistically with pollution. Other pollution indicators (biochemical, physiological, genetic, behavioral, and ecological) have also received some attention, as have body burdens of contaminants in aquatic species. Research, especially that conducted during the past decade, has done much to clarify the many pathways and toxic effects of contaminants on aquatic animals, and has also helped to identify mechanisms for survival of fish and shellfish in the presence of environmental changes caused by human activities.  相似文献   

8.
ABSTRACT: Rapid biological information systems using aquatic organisms to monitor water and waste water quality have only recently begun to develop technologically for practical on-site applications. One approach which has been demonstrating its feasibility recently monitors the ventilatory behavior of fish to assess, for example, the quality of drinking water supplies and industrial waste water discharges. A comparison of the basic strategies of the various biological monitoring systems making use of this concept is presented. In addition, the applications and potential utilization of these systems are discussed.  相似文献   

9.
A paired watershed study was conducted in western hemlock/western redcedar/Douglas fir forests of southwestern British Columbia to assess the effects of clearcutting and clearcutting plus slash-burning treatments on stream water characteristics. In the case of stream temperatures, both treatments increased summer temperatures as well as summer daily temperature fluctuations. These effects lasted for seven years in the case of the clearcut stream but longer in the case of the clearcut and slashburned stream. Clearcutting increased winter stream temperatures whereas slashburning caused a decrease. These changes lasted less than four years. Clearcutting and slashburning had a greater impact on stream temperatures than did clearcutting alone.  相似文献   

10.
ABSTRACT. Beginning of month water temperature profiles are estimated for each lake. These water temperature profiles along with surface water temperatures are used to determine the effects of thermal expansion and contraction of water on the net basin supply values obtained from water balance studies using end of month lake levels. It is demonstrated that net basin supply values (equivalent to precipitation on the lake minus the evaporation from the lake plus the runoff into the lake) obtained from water balance studies without accounting for the thermal expansion and contraction of water may be in error by as much as 100 percent during some months for each lake.  相似文献   

11.
ABSTRACT: During the summers of 1982, 1983, and 1985, we assessed the effects of placer mining sedimentation on Arctic grayling, Thymallus arcticus, in the headwaters of Birch Creek, northeast of Fairbanks, Alaska. We compared differences between two streams (one that was undisturbed and one with mining activity upstream) near the confluence. Studies of caged fish demonstrated that, if grayling could not escape from streams carrying mining sediments, they would either die at high rates (sac fry) or suffer gill damage, starvation, and slowed maturation (age-O fingerlings and age-2 juveniles). Indirect effects of sedimentation, through loss of summer habitat for feeding and reproduction, may more severely affect grayling populations than the direct effects of sedimentation on the health and survival of individual fish.  相似文献   

12.
ABSTRACT Two lakes having similar soil types were studied to determine the effects of age and water fluctuations on plankton, benthos and fish populations. Bluff Lake is an older man-made lake which is drawn down in the mid-summer. Oktibbeha County Lake is a young lake and the water levels are maintained. Chemistry data from the two lakes indicate that their chemical properties are very similar. Neither lake would be considered very fertile. Net plankton populations in Bluff Lake and Oktibbeha County Lake were comparable when analyzed on a number of organisms per liter basis. Fluctuations of water levels did not seem to have an effect on the net plankton populations. The benthic population in Bluff Lake is slightly higher than that found in Oktibbeha County Lake. This is true for both numbers and weight per square meter. The species composition of benthic organisms in the two lakes were similar. Based on one-acre samples from each lake, Bluff Lake has a more balanced fish population than does Oktibbeha County Lake. Neither, however, seems to support populations of game fish in which a high percentage of these are in the available or harvestable range. Both lakes contain high populations of gizzard shad.  相似文献   

13.
Power plant water consumption (evaporative water loss) for various river temperature standards is presented for existing and proposed power plants located along the Missouri and Upper Mississippi Rivers in the MAPP geographical area. Thermodynamic and economic models are combined to evaluate the cooling related water consumption at various river thermal standards. The existing thermal standards and a number of other hypothetical thermal regulations including the extreme cases of no thermal standards and no allowable heated discharges are examined to show the dependence on thermal standards of power production related water consumption. A critical appraisal of the cost of thermal standards in terms of water consumption is thereby possible so that subjective assessments of the standards can proceed with full knowledge of the tradeoffs involved between the “water costs” of power production and environmental enhancement.  相似文献   

14.
ABSTRACT A model was developed for predicting mean daily, mean daily minimum, and mean daily maximum temperatures in West Virginia. The model is easily used since the only inputs are elevation, latitude, and julian date. With local calibration, the model is expected to apply to other areas in the Appalachian region.  相似文献   

15.
The bluespotted sunfish, Enneacanthus gloriosus (Holbrook), had a final temperature preferendum of 31.5 C. Fish acclimated to 30 C avoided 36 C. The analysis of acute temperature preference data and the relationship between final temperature preferendum and upper avoidance temperatures are discussed.  相似文献   

16.
ABSTRACT The effects of maintaining a 19 ha Colorado montane reservoir in a thermally destratified condition for one year were evaluated. Water temperatures were kept nearly vertically agd horizontally isothermal throughout the year. The weighted mean temperature of the lake was 1-4°C colder in winter and 1-2°C warmer in summer than normal. Deep water in summer was up to 6°C warmer than typical hypolimnion temperatures, but summer surface temperature was unaltered. Without destratification dissolved oxygen depletion develops in summer and winter, but by eliminating stratification, oxygen was kept near saturation throughout the year. Alkalinity, pH, conductivity, and total residue were not significantly affected. Seston decreased which was probably due to declines in planktonic diatom populations. Increases in iron and manganese did not occur in deep water during destratification. Calcium concentrations increased slightly. Magnesium and most anions (chloride, nitrate-N, and silica) were not greatly altered, but sulfate concentration was reduced. Artificial destratification, as a reservoir management tool, will be very useful in altering chemical problems; particularly increasing oxygen and decreasing iron and manganese concentrations.  相似文献   

17.
ABSTRACT: A hydroelectric lake on the Oconee River in central Georgia was sampled on a quarterly basis for four years to determine the impact of three insecticides on the pesticide loading of fish. The insecticides carbofuran (2,3,-dihydro-2,2-dimethyl-7-benzofuranyl methyl-carbamate), fenvalerate [cyano(3-phenoxyphenyl)methyl 4-chloro alpha (1-methylethyl)benzeneacetate], and azinphosmethyl [0,0-Dimethyl S-(4-oxo-1,2,3-benzotriazin-3-(4H)-ylmethyl phosphorodithioate] were used to control cone and seed insects on a pine seed orchard that is adjacent to Lake Oconee. Fish populations in areas of the lake that receive runoff from treated and untreated portions of the seed orchard were sampled using gill nets. Water and fish samples were collected monthly in 1981–1983 and quarterly in 1984. Species collected included carp (Cyprinus carpio), sucker (Catostomus spp., Erimyzon spp., Moxostoma spp., Minytrema spp.), bass (Micropterus spp.), channel catfish (Ictalurus punctatus), spotted gar (Lepisosteus spp.), and bluegill sunfish (Lepomis macrochirus). Few carbofuran residues (< 7 percent of fish samples contained detectable residues) and no azinphosmethyl or fenvalerate residues were detected despite measured inputs into the lake after insecticide application. Persistent agricultural insecticides including dieldrin, lindane, DDT, and toxaphene were detected in 32, 36, 58, and 83 percent of sampled fish, respectively. Screening for 20 other insecticides resulted in no detection of residues at a detection limit of 30–100 μg kg-1.  相似文献   

18.
ABSTRACT Minicomputer interfaced, continuous, noncontact sensing of the ventilatory behavior of the bluegill (Lepomis macrochirus) was used to investigate the response to exposure to solutions of copper and zinc under various modes of application. The results of these studies indicate that fish respond to sublethal concentrations of these toxicants by increasing the average ventilatory rate as well as decreasing the amplitude of the ventilatory signal. Appropriate statistics for the analysis of these data are also described.  相似文献   

19.
ABSTRACT: The hypothesis of this paper is that the frequently used regulatory practice which employs point estimates in water pollution control objectives, in combination with monitoring at infrequent intervals, is an inadequate scientific procedure for the measurement and control of pollution. The first part of this paper outlines the relevant sampling theory which applies to the measurement of effluent from industrial plants and describes the possible errors in sampling practice which currently affect the interpretation and enforcement of environmental standards. In the second part of the paper, the authors describe briefly the environmental significance of biological damage functions. In the final part of the paper, the authors recommend that existing pollution control regulations be restructured to be more efficient and effective in the protection of both corporate and social interests. By adopting two different approaches to regulation depending upon the nature of the appropriate damage functions and critical fish species, it is possible to reduce significantly the waste of resources.  相似文献   

20.
ABSTRACT: Utilizing predictions of pollutant movement generated by the CREAMS model, the economics of reducing field losses of sediment and nitrate percolation were compared between two soil types on each of two slopes common to the Upper Eastern Shore of Maryland. The soils considered were Matapeake silt loam and Sassafras sandy loam textures on field slopes of 3.5 percent and 7.5 percent. A representative cash grain farm was used as a basis of comparison. Under assumptions of profit maximization, economic optimal cropping systems varied by slope. Results further indicated that relative cost-effectiveness of sediment or nitrate percolation control varied by soil type for both slopes considered. Unit costs of sediment control were less on silt loam soils, while unit costs of nitrate percolation control were less on sandy loam soils.  相似文献   

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