摘要:

ABSTRACT:Bayesian and non‐Bayesian flood levee design methods that account for the uncertainty due to limited record length are compared using a case study. The first method, Bayesian decision theory (BDT), imbeds the uncertainty in the parameters of the yearly peak stage into a loss function. The optimum design of the flood levee, called Bayes design, corresponds to the minimum expected loss, called Bayes risk. The second method, induced safety algorithm (ISA), computes a margin of safety to be added to either an existing levee or a levee designed by classical benefit‐cost analysis. The design decision is shown to fluctuate as different record lengths are considered. For short record lengths, BDT, which takes small sample bias into account, appears to yield a more conservative design than ISA. On the other hand, ISA, which is simple to implement, seems to be preferable to BDT for longer record leng

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1975.tb00696.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

ABSTRACT:In a joint undertaking by The MITRE Corporation and the EPA Office of Water Programs Operations, three indices were developed: (1) An index of water quality; (2) An index of the need for abatement action; and (3) An index of the need for water quality management planning. These indices were evaluated for some 1000 planning areas (sub basins, regional planning jurisdictions, metropolitan areas, etc.) which together cover essentially all of the area of the 48 contiguous states.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1975.tb00697.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

ABSTRACT:A lake or reservoir, heated mainly through the air‐water interface, is visualized as a solid which is bounded by the interface plane (x = 0) and extends to infinity in the positive x‐direction. Analytical expressions give the surface temperature, the temperature profile (with depth) and the position of the thermocline as a function of time (Julian Day). Preliminary model results indicate that the general shape of the temperature profile and the position of the thermocline are influenced primarily by the air‐water heat exchange and the time lapse since an isothermal condition existed in the water

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1975.tb00698.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

ABSTRACT:Traditional development in South Florida has in many cases resulted in undesirable degradation of terrestrial and aquatic ecosystems, due to overdrainage and overenrichment of surface waters. The study described in this paper was undertaken in order to establish guidelines under which urban development may take place in coastal areas, while minimizing unwanted environmental changes. The study area consists of approximately 70 square miles of relatively flat land in Collier County, Florida. The coastal wetlands of the region are a highly valued natural resource containing the Rookery Bay Wildlife Sanctuary. The upland properties are mainly pine woodlands and have great potential for development. A master plan was developed which will (1) provide adequate drainage for existing and projected development within the study area and (2) maintain the integrity of the estuarine zone. The major recommendations of the plan relate to land use, physical control of surface waters, including construction and maintenance of the water management system, and implementation of the plan.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1975.tb00699.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

ABSTRACT:An environmental simulation model of the Upper St. Johns River Basin, Florida, has been developed in order to predict hydrologic responses under proposed management plans. Land use projections for each of 19 hydrologic planning units are provided by a linear programming analysis of agricultural activities. Inputs to the model include rainfall, runoff, evapotranspiration (ET), aquifer properties, topography, soil types, and vegetative patterns. A water balance is developed in the uplands based on infiltration, ET, surface runoff, and groundwater flow. Valley continuity is based on stage‐volume relationship for inflows and outflows and a variable roughness coefficient dependent on vegetative patterns. Land use changes form the basis for predicting hydroperiod variation under alternative management schemes. Plans are ranked according to two criteria, deviation from a natural hydroperiod and flood or drought control provided. Results indicate that (1) a single reservoir without irrigation and (2) floodplain preservation plans are superior to (3) multiple reservoir with irrigation and (4) uncontrolled floodplain plans with regard to both criteri

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1975.tb00700.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

ABSTRACT:This study examines agricultural land use change in the flood plain of the Iowa River as a result of building the Coralville Dam. Estimates of land use change and the benefits realized from the project are compared to the original project study benefits estimated by the Corps of Engineers. An analysis of the factors affecting land use change is carried out through a regression model to determine those variables that explain observed land use change.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1975.tb00701.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

ABSTRACT:Deoxygenation process in which carbonaceous BOD is biochemically oxidized to reduced inorganic compounds is of great significance in the oxygen demand of stream waters. The BOD decay rate traditionally determined in a laboratory might not necessarily be the same as estimated for a natural stream. The variation in biochemical activity could occur due to differences in adsorption, dispersion, and biophysical processes taking place in the two environments. The first stage biochemical oxygen demand and benthal oxygen demand that occur simultaneously in a stream, have been considered together to calculate the gross rate of deoxygenation in polluted waters. The available data on deoxygenation measurements has been analyzed in this study to calculate the carbonaceous BOD rate constants in natural streams. The analysis indicates that the dimensionless deoxygenation parameter is a function of the ratio of the Reynolds number and Froude number of flow. The functional relationship between these two parameters essentially follows a straight line on a log‐log plot. The applicability of the relationship does not depend upon the volume of the organic load, size, or location of the strea

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1975.tb00702.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

ABSTRACT:This study presents generalized and special forms of hydraulic solutions of surface water lag time, as conceptualized by Overton (1970), for the converging overland flow. It is shown that these solutions can be used to estimate lag time from physically measurable information on a given watershed.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1975.tb00703.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

ABSTRACT:Sewage effluent is commonly disposed of on land in arid regions, and the majority usually recharges the groundwater. Few evaluations have been made of the effect of effluent disposal on groundwater quality in the west. Groundwater hydrologists are rarely involved with treatment plant design and operation or effluent disposal in the San Joaquin Valley, California. The author's purpose is to evaluate the effect of regional sewering programs on groundwater quality in this valley. Research was conducted on past studies of sewage effluent disposal. An extensive water sampling program was undertaken near the Fresno Sewage Treatment Plant. Chloride contents were used to trace recharged effluent. The extent of recharged effluent was delineated and traced for about ten miles. Sampling between the plant and the urban Fresno area indicated a high probability of large‐scale leakage of raw sewage into the groundwate

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1975.tb00704.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

ABSTRACT:The individual hydrologic components are assumed to be normally distributed for each month and linear regression equations are estimated for predicting the value of the individual monthly hydrologic components. It is shown that some of the hydrologic components for downwind (in this case downstream) lakes are dependent upon hydrologic events for the upwind lakes. This is particularly so for precipitation in the downwind lake basins which appears to be dependent upon evaporation values for upwind lakes.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1975.tb00705.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY