摘要:

ABSTRACT: A brief review of environmental assessment methods is presented as an introduction to a study of environmental management problems in a coastal area of southern Louisiana. The assessment method used in the study is called suitability analysis and involves the use of matrices. The matrix approach is simply a convenient method for organizing all factors representing environmental concerns in a region. The matrices proved to be very useful in defining the present state of an environmental regime and in maintaining an inventory of regional features and potential impacts.The method is described in detail and illustrated by evaluating the potential impacts of a major pipeline construction job in the area. Of major concern is the potential impact on the water resources of the region. Disruption to the natural drainage could be detremental, and affect the suitability of available water for a given use. Limitations of the method are discussed and potential areas for improvement and research are noted. Coupled with an economic assessment, the suitability analysis method should prove beneficial for selecting development sites for industries, residential areas, and other construction activities.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1984.tb04634.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACT: Using data from 80 Oregon watersheds that ranged in size from 0.54 km2to 27.45 km2, equations were developed to predict peak flows for use in culvert design on forest roads. Oregon was divided into six physiographic regions based on previous studies of flood frequency. In each region, data on annual peak flow from gaging stations with more than 20 years of record were analyzed using four flood frequency distributions: type 1 extremal, two parameter‐log normal, three parameter‐log normal, and log‐Pearson type III. The log‐Pearson type III distribution was found to be suitable for use in all regions of the State, based on the chi‐square goodness‐of‐fit‐test. Flood magnitudes having recurrence intervals of 10, 25, 50, and 100 years were related to physical and climatic characteristics of drainage basins by multiple regression. Drainage basin size was the most important variable in explaining the variation of flood peaks in all regions. Mean basin elevation and mean annual precipitation were also significantly related to flood peaks in two regions of western Oregon. The standard error of the estimate for the regression relationships ranged from 2

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1984.tb04635.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACT: The Hydrologic Engineering Center, Corps of Engineers, has been engaged in research, training, and project assistance in non‐structural flood control planning for Corps offices across the United States since 1975. Lessons learned from this experience deal with the role of nonstructural measures in flood plain management, the role of creativity in analysis, the role of analysis, and tools for analysis. The role of nonstructural measures in flood control planning depends upon the scale of the problem, the nature of the measure, the degree of protection desired, and whether damage is to existing or future property. An earnest seeking for nonstructural opportunities, a field presence for their formulation, and compatbility with local infrastructure plans are prerequisite to creative use of nonstructural measures. Analysis is a necessary complement of creativity. Several tools for nonstructural analysis have been developed and applied to flood problems involving several hundred and several thousand structure

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1984.tb04636.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACT: The Hallett Quarry gravel pit lakes are an active sand and gravel extraction operation located 0.4 km north of the City of Ames, Iowa. During periods of drought, these lakes serve as a supplemental water supply for Ames. A modified version of the Vollenweider input‐output model was used to predict future water quality under various watershed land use, drainage, and lake configurations. The dominant factor controlling the future water quality of the lakes was found to be the nutrient input. It is recommended that a management plan to protect the future water quality should be oriented towards reducing the sources of phosphorus to the lake

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1984.tb04637.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACT: Concentrations of total nitrogen, total phosphorus, and total organic carbon in the Loxahatchee River estuary decreased with increasing salinity in a manner indicating that mixing and dilution of freshwater by seawater was the primary process controlling the down‐stream concentrations of nutrients. Most of the nutrients in the surface freshwater inflows entered the estuary from five major tributaries; however, about 10 percent of the total nitrogen and 32 percent of the total phosphorus were from urban stormwater runoff. The input of nutrients was highly seasonal and storm related. During a 61‐day period of above average rainfall that included Tropical Storm Dennis, the major tributaries discharged 2.7 metric tons of total phosphorus, 75 metric tons of total nitrogen, and 1,000 metric tons of organic carbon to the estuary. This period accounted for more than half of the total nutrient load from the major tributaries during the 1981 water year (October 1, 1980, through September 30, 1981). Inorganic phosphorus and nitrogen increased relative to total phosphorus and nitrogen during storm runoff. Nutrient yield from the basin, expressed as grams per square meter of basin area, was relatively low. However, because the basin area (544 square kilometers) is large compared with the volume of the estuary, the basin might be expected to contribute significantly to estuarine enrichment were it not for tidal flushing. Approximately 60 percent of the total volume of the estuary is flushed on each tide. Because the estuary is well flushed, it probably has a large tolerance for nutrient load

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1984.tb04638.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACT: Urban stormwater runoff has been recognized as a potential major contributor of pollution to receiving waters. However the projected high costs of control have prompted an examination of the extent to which these impacts have been documented. A nationwide search was conducted for case studies demonstrating a cause‐effect linkage between urban runoff and impairment of beneficial uses in receiving waters. The results indicate that numerous definitions of “impacts” are being used and that few substantive data exist to support many of these allegations. Results of a preliminary impact assessment are presented for the 248 urbanized areas of the United States. Then, the results of more recent efforts to assess these impacts in several case studies are described. This assessment demonstrates the critical need for additional short‐term and long‐term sampling

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1984.tb04639.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACT: With the advent of standards and criteria for water quality variables, there has been an increasing concern about the changes of these variables over time. Thus, sound statistical methods for determining the presence or absence of trends are needed. A Trend Detection Method is presented that provides: 1) Hypothesis Formulation ‐ statement of the problem to be tested, 2) Data Preparation ‐ selection of water quality variable and data, 3) Data Analysis ‐ exploratory data analysis techniques, and 4) Statistical Tests ‐ tests for detecting trends. The method is utilized in a stepwise fashion and is presented in a nonstatistical manner to allow use by those not well versed in statistical theory. While the emphasis herein is on lakes, the method may be adopted easily to other water

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1984.tb04640.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACT: Results of computer calculations are presented which predict the pressure response of a closed casing annulus of an injection well to temperature and pressure variations of the injected waste stream. For example, a 3000 ft. disposal well receiving fluid at 100d̀F might cause an increase in annular pressure of some 500 psi. Graphs summarizing these results are included. The results will be of interest to waste injection well operators, inasmuch as they are required to monitor annulus pressure to prove mechanical integrity of their injection wells

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1984.tb04641.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACT: Cowpies molded to a standard configuration and size were subjected to simulated rainfall, and the fecal coliform counts were determined using the most probable number (MPN) method of enumeration. The standard cowpie deposits were exposed to simulated rainfall once at ages 2 through 100 days. The effects of rainfall intensity and recurrent rainfall were also tested. Naturally‐occurring fecal deposits were also tested to compare their results with those from the standard cowpies.A log‐log regression was found to describe the decline in peak fecal coliform release with fecal deposit age. The 100‐day‐old fecal deposits produced peak counts of 4,200 fecal coliform per 100 milliliters of water. This quantity of release is minimal compared to the release from fresher fecal material.Rainfall intensity had little effect on peak fecal coliform release from fecal deposits that were 2 or 10 days old. At age 20 days the effect of rainfall intensity was significant; the highest intensity gave the lowest peak counts, and the lowest intensity gave the highest peak counts. The effect of rainfall intensity appears to be related to the dryness of the fecal deposits.Peak fecal coliform counts were significantly lowered when the fecal deposits were rained on more than once. This decline was thought to be produced by the loss of bacteria from the fecal deposits during the previous wettings.Standard cowpies produced a peak release regression that was not significantly different from the regression for the natural fecal deposits. Apparently, grossly manipulating the fecal deposits did not significantly change the release p

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1984.tb04642.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ABSTRACT: Adequate water supplies are critical to the maintenance of a community's health and economic well‐being. Across the nation communities are struggling to meet an expanding demand for water from municipal, industrial, agricultural, recreation, water quality, and power generation users. As the demand grows and communities actively compete with one another for a limited water supply, states are being called upon to help solve the problem. One possible solution that is being used in many areas is the development and implementation of a water conservation program to stretch the limited supply as far as possible. using a mailed survey, state water conservation programs and some of the characteristics of the different programs were documented. Responses to the nationwide survey were obtained from all 50 states. The specific water conservation program elements on which information was received from the survey included laws and restricted use, community assistance, education, research, and other services. Recommendations for states developing or considering the development of a water conservation program are outline

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1984.tb04643.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY