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1.
ABSTRACT: Outdoor recreation is a major, growing use of water resources in the United States. The economic effects of expenditures by visitors to three recreational river sites on local economies surrounding the sites were estimated using an input-output model (IMPL.AN). Expenditure data were from the Public Area Recreation Visitors Study (PARVS). Results indicate that visitor spending stimulates a considerable amount of economic activity and growth in local economies. Economic effects include increases in total gross output ranging from $2.6 million to $13.4 million, increases in total income ranging from $1.2 million to $5.6 million, and increases in employment ranging from 60 to 292 jobs.  相似文献   

2.
ABSTRACT: Parts of the Raritan River basin in central New Jersey have undergone increasing development over the last several decades. The increasing population relies on the region's ground water and surface water sources for its residential, commercial, and industrial water supply. Urbanization, regionalized wastewater-treatment facilities, stream channel alterations, and interbasin transfers of water can all affect water availability. This pilot study was conducted to determine whether significant trends exist in the base-flow and overland-runoff characteristics of streams in two subbasins with different percentages of urban/built-up land (Anderson et at., 1976). Changes in flow characteristics that could indicate future reductions in safe water yield of the Raritan River basin were examined. Flow and flow variability of the steams draining these two subbasins have increased over time. Many of the flow measures studied experienced pronounced trend shifts about 1960. The cause of these changes cannot be readily determined from the data, nor is it clear whether the increased flow variability lies outside the natural range of flow variability of the streams draining the subbasins.  相似文献   

3.
ABSTRACT: The national and regional economic impact of the Bureau of Reclamation's Uncompahgre Project which was authorized in 1903 is assessed. Benefit-cost ratios for the project are calculated for a range of production cost estimates and discount rates. An economic base approach is used to estimate the project's regional economic impact. Although the project has been marginal in terms of an economic efficiency rationale it has been an important impetus to regional economic growth in the Uncompahgre Region over time.  相似文献   

4.
ABSTRACT: The effect of a floodplain location on the market value for property is controversial, with the conventional wisdom being that buyers are myopic. Previous parametric and nonparametric statistical tests have proven inconclusive in deciding the issue. Herein, a theoretical model, that of hedonic price indexes, is posited and tested, using housing sales characteristics data obtained from a Multi-List Service cooperative. This study suggests that home buyers do adjust the purchase price for houses within a floodplain, and this amounts to, on average, just over 12 percent. The data are from a small midwestern town in which the last severe flooding occurred a decade ago.  相似文献   

5.
ABSTRACT: Crystal Lake, a small urban lake in Robbinsdale, MN, had been artificially circulated for 12 years before a detailed water quality evaluation was undertaken. In 1986, the circulation system was shut off for a two-year assessment. Although the lake remained hypereutrophic, the use of the lake, which included shoreline fishing and feeding ducks and geese, did not appear to be seriously impaired by the absence of artificial circulation. The circulation system was returned to service in October 1987 (there are 16 diffusers in this 0.31 km?2 lake). Continuous limnological data from October 1987 through October 1988, plus several sampling dates in 1989, compares to the two non-circulation years (1986 and 1987) as follows: there was a two- to three-fold increase in the lake's concentration of total phosphorus, total Kjeldahl nitrogen, and chlorophyll and a similar decrease in Secchi disk transparency. The surface oxygen concentration was reduced and the deep waters were nearly anoxic. In fact, following a wind storm in 1988, the entire lake became anoxic due to the mixing of high BOD throughout the water column, and a summertime fish-kill resulted. All of these occurrences are related to the artificial circulation of the lake.  相似文献   

6.
ABSTRACT: Socioeconomic determinants of individual household water use were estimated using regressions of these characteristics with actual household water use for winter and summer. Results were disaggregated between those consumers who were aware of an increasing block rate price structure and those who were not. Most of the informed group members believed that this price structure did result in significant reductions in water use. Nevertheless, overall water use was greater for the informed group. The determinants of water use were found to differ between informed and uninformed users as well as between winter and summer. The uninformed users were influenced by a larger set of variables in each season than the informed group. In winter, the informed group members with swimming pools and/or arid landscaping used less water than their uninformed counterparts. Summer water use increased with length of tenancy in home for the uninformed group but not for informed, while increasing with ownership for informed consumers.  相似文献   

7.
ABSTRACT: water resources supply and demand time series consist of several or all of the four basic characteristics: tendency, intermittency, periodicity and stochasticity. Their importance changes from one type of variables to another. Historic developments of analysis of time series in hydrology have varied significantly over the past, from the stress on search for periodicities and persistence in annual series to the emphasis on the series stochastic properties. Supply and demand series are often highly interrelated, which fact is most often neglected in planning water resources systems in general, and water storage capacities in particular. The future of series analysis in water resources will likely be by a joint use of physically-based structural analysis and the use of advanced methods of treating data by stochastic processes, statistical estimation and inference techniques. The most intriguing challenge of the future of this analysis may be the treatment of nonnormal, nonlinear and in general nonstationary hydrologic and water use time series. The proper treatment of complex multivariate processes will also challenge the specialists, especially for the purposes of transfer of information between data on variables at given points, or between data at several points of a given variable, or both.  相似文献   

8.
ABSTRACT: This paper evolved from a concern that water resource administrators and planners do not have a consistent definition of the value of goods and services of outputs from projects and programs. A more flexible approach to planning and evaluation is presented that recognizes the interaction of production and consumption through the use of commodity demand curves. Use of the concept of consumer surplus permits measurement of the differential impacts on producers' and consumers' welfare. Quadratic programming is suggested as a consistent means of quantifying these differential impacts.  相似文献   

9.
ABSTRACT: The effects of a moving rainstorm on flood runoff characteristics were investigated. A flood hydrograph simulation model called “FH-Model” and a natural watershed were used. A hypothetical rainstorm of 50 years recurrence interval, 75 mm depth, and 4 hours duration was used to show the effects of velocity and direction of the moving rainstorm on the runoff characteristics. Compared with an equivalent stationary rainstorm (ESRS), the peak flow caused by a rainstorm moving in a downstream direction with a speed equal to channel velocity, V, was 27.5 percent higher and the peak flow caused by the same rainstorm moving in an upstream direction was 21.7 percent smaller. These percentages reduced to 10.5 percent and 8.6 percent for storms moving downstream and upstream, respectively, at three times the channel velocity, 3V. There were negligible differences in the time of peak, Tp between runoff caused by storms moving downstream and runoff produced by ESRS. However, Tp for a storm moving upstream at V velocity was 82 percent higher than that produced by ESRS, but was reduced to 27 percent higher when the storm velocity was 3V.  相似文献   

10.
ABSTRACT: Artificial circulation was applied at East Sidney Lake, a small, eutrophic impoundment in New York, to improve the water quality of the reservoir and tailwater. Treatment was successful at both reducing the stability of the reservoir and maintaining higher mean oxygen concentrations in the bottom waters. Discharge waters had lower metals and phosphorus concentrations during treatment years. However, vertical temperature differences, although minimal, were still sufficient to permit chemical stratification and some phosphorus release from the sediments. Frequent mixing events during periods of low stability, and runoff from storm events, also appeared to increase transport of phosphorus into the epilimnion. Overall, treatment did not result in decreases in algal populations or improvements in water clarity.  相似文献   

11.
ABSTRACT: This paper presents estimates of the statewide economic impacts of guided whitewater rafting on five rivers in six states: the Nantahala (North Carolina), Gauley (West Virginia), Kennebec (Maine), Middle Fork of the Salmon (Idaho), and Chattooga (Georgia-South Carolina). Except for the Chattooga and Middle Fork, rafting is dependent on upstream dam releases. Guide fees range from about $15 per trip on the Nantahala to over $1,000 on the Middle Fork. Economic impacts per nonresident 1000 visitors increase along with length of the rafting trip and remoteness of the river. Total industrial output per 1000 nonresident visitors ranged from $95,000 on the Nantahala to over $2.5 million on the Middle Fork. However, because of differences in annual visitation levels, total impacts were greatest at the Nantahala, at over $14 million in 1993. Multipliers for all economic measures were relatively consistent over the rivers. Employment multipliers (Type III) ranged from 1.67 to 1.90, income multipliers from 2.0 to 2.4, and industrial output multipliers from 2.1 to 2.5.  相似文献   

12.
ABSTRACT: Use-oriented benefits and treatment costs analysis has been incorporated into a water quality index to show an economically optimized concentration for the treatment of the pollutants and the resulting water quality. This combined water quality index can be used in decisionmaking at the federal and local government levels. Five major pollutants, i.e., coliforms, nitrogen, phosphorus, suspended solids, and detergent, have been considered for the municipal waste water. With each higher level of improvement the treatment costs increase accordingly and the benefits associated with the reuse of this treated waste water will increase too but not for the nutrient removal in agricultural use. The optimal concentration is determined when the marginal costs equal the marginal benefits. The combined water quality index is the combination of the maximum net benefits and the water quality index of the optimized residual concentrations. This water quality index is zero dollars for the Tucson region in this study. The possible reclaimed use of municipal waste water is for agricultural irrigation and recreational lakes for the Tucson region.  相似文献   

13.
ABSTRACT: Investigations were initiated to evaluate the effects of sedimentation on the algal composition, primary productivity rates and chemical nutrient concentrations of a 17 acre recreational impoundment in central Virginia. Comparisons during the winter seasons of 1972–1973 indicated that as a result of sedimentation, from lake front home construction, the total numbers of algal genera in the lake decreased from 24 to 16, productivity as measured by 14CO2 and total extractable chlorophyll decreased two fold, and several important nutrients, i.e. NH4+-N, SiO2 and PO4-P increased significantly.  相似文献   

14.
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   

15.
For optimal allocation of resources, it is critical to arrive at proper estimations of direct benefits created by irrigation projects. This paper reviews critically the traditinal procedures of estimating the direct irrigation benefits and, in this context, presents formulas to show the extent of bias in them. The paper further discusses the implications of shifts in demand over time for biases in the estimation of direct benefits through traditional procedures and provides altenate procedures for the proper estimation of direct irrigation benefits. In this context, it throws some light on the exact distribution of benefits between consumers and producers.  相似文献   

16.
ABSTRACT: Autoregressive moving average (ABMA) models have been applied to study the flow series of the karstic springs of La Villa, Fuente Mayor (Spain), and Aliou (France). The theoretical meaning of the parameters involved in the model upon applying it to a simplified scheme of the emptying of a karstic aquifer is first analyzed. The types of transformations necessary to apply these models to the flow series that lack normality and have strong periodic components are also indicated, as are the advantages of this type of model and the physical significance of the parameters obtained, with respect to the standpoint of hydraulics, ranging from rather homogeneous aquifers (La Villa) to extremely karstic (Aliou), including aquifers with intermediate characteristics (Fuente Mayor).  相似文献   

17.
This paper focuses on two factors that influence the acceptability of the expected value criterion as a method of handling risk or uncertainty in decision-making where damages from unusual physical occurrences such as hurricanes or floods must be considered. These are the length of time of project existence and the problem of obtaining accurate estimates of the probability of occurrence for different sizes of natural disasters. The problem of estimating accurate probabilities of occurrence for different sizes of natural disasters is not as great as it might appear and in most situations will not defeat the usefulness of the method. The time span during which the project is expected to exist has greater implications for the usefulness of the expected value approach appears highly applicable. However, it becomes less applicable for projects that are short-term in nature. The basis for distinguishing between short- and long-term projects is presented.  相似文献   

18.
ABSTRACT: Zooplankton samples and dissolved oxygen-temperature readings and water samples were taken from a treatment and control pond on 41 and 42 separate occasions, respectively, both before and after the application of 5.0 mg/l (a.i.) dipotassium endothall to the 0.31 ha treatment pond on May 31, 1973. Seasonal fluctuations in the density of Cladocera and Copepoda coincided quite closely in both ponds and were similar to the fluctuations reported in the literature to be typical of temperate region ponds and lakes. An apparent seasonal shift in generic composition from .Daphnia spp. in May to Ceriodaphnia spp. in June to Chydorus spp. from July/early September occurred in both ponds and is thought to be at least partially due to fish predation. No apparent changes in species composition or generic densities of Cladocerans was noted in the treatment pond that did not also occur in the control pond. There were no noticeable effects of the dipotassium endothall on either the Calanoida or Cyclopoida suborders of Copepoda. A later pulse of Ostracoda in the treatment pond, when compared to the control, may have been due to the dipotassium endothall or to a combination of the effects of the herbicide on the macrophytes and the method of sampling. A decrease in dissolved oxygen below saturation, occurring in the treated pond from 3–21 days after treatment, was attributed to an increase in biological oxygen demand associated with weed-kill. There was no noticeable increase in plant nutrients (N and P) in the treated pond following herbicide application, nor were there any apparent changes in the other chemical parameters studied.  相似文献   

19.
ABSTRACT: The Chubb/Bauman (Ch/B) method for making quantitative estimates of recreation potential for rivers is based on the 1968/ 69 Leopold method for quantitative assessment of the scenic beauty of rivers. Both use classifications of environmental variables as the database. Unlike the Leopold method, the classifications used in the Ch/B method consistently reflect human preferences. The Ch/B method collects information on 67 variables, and uses a computer program to produce estimates of potential for 16 common recreation activities. This critique evaluates selected concepts and procedures of the Ch/B method partly by comparison with other available methods of recreation resource inventory. It considers the validity and utility of numerical weighting of variables, the use of numbers derived from place in a classification, and the transformation process. The quantitative techniques of the method exhibit serious flaws. Much of the data produced by the method appears to be quantitative but in fact is not, and it does not produce truly quantitative estimates of recreation potential. Classifications of generalized geographic or environmental variables are shown to have serious defects as a basis for evaluation of recreational potential.  相似文献   

20.
ABSTRACT: In 1983, the City of Indianapolis, Indiana, completed construction of advanced wastewater treatment (AWT) systems to enlarge and upgrade its existing Belmont Road and South port Road secondary treatment plants. A nonparametric statistical procedure, a modified form of the Wilcoxon-Mann-Whitney rank-sum test, was used to test for trends in water quality at two upstream and two downstream sites on White River and at the two treatment plants. Results comparing the pre- (1978–1980) and post- (1983–1986) AWT periods show statistically significant improvements in the quality of the treated effluent and of the White River downstream from the plants. Water quality at sites upstream from the city was relatively constant during the period of study. Total ammonia (as N) decreased 14.6 mg/L and BOD5 (five-day biochemical oxygen demand) decreased 10 to 19 mg/L in the two effluents. Total ammonia in the river downstream from the plants decreased 0.8 to 1.9 mg/L and BOD5 decreased 2.3 to 2.5 mg/L. Nitrate (as N) increased 14.5 mg/L in the plant effluents and 2.0 to 2.4 mg/L in the river because of in-plant nitrification. Dissolved oxygen concentration in the river increased about 3 mg/L because of reduced oxygen demand for nitrification and biochemical oxidation processes.  相似文献   

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