OPTIMAL IDENTIFICATION OF MUSKINGUM ROUTING COEFFICIENTS1

Traditionally, identification of the Muskingum routing coefficients has been based on observations of the linearity of a loop formed by graphically plotting a forward and a reverse path. This graphical procedure is time-consuming and may not minimize the error of estimation. A procedure was developed to improve the drawbacks of the graphical method. This procedure calls for (a) the use of least square regression on the forward and reverse paths to determine their respective slopes, and (b) the use of statistical t-test to evaluate the hypothesis that these two slopes are equal. The computational procedure is repeated, using incremental values of the flow weighting coefficient, x. A graph of the computed t-value versus x can be constructed. The optimal value of x, as read from the graph, occurs at the minimum computed t-value. The procedure has been demonstrated superior to the graphical method for three illustrative examples, resulting in a reduction of the error squares by factors ranging from 5 to 6.     

EFFECTS OF COAL PILE RUNOFF ON STREAM QUALITY AND MACROINVERTEBRATE COMMUNITIES1

Samples of coal pile runoff, Georges Creek water, and macrobenthos above and below two coal storage areas along Georges Creek, Allegany County, Maryland, were collected in July, August, and September 1982, and February and July 1983. Coal pile runoff was collected under high- and low-flow conditions. Water samples were analyzed for Hg, Zn, As, Fe, Mn, Al, SO₄^?2, pH, filterable and non-filterable residue, conductivity and acidity. Leachate from coal piles along Georges Creek contained high concentrations of heavy metals, particularly manganese, aluminum and zinc. Iron and sulfate were very high and the pH ranged from 1.4 to 3.1. Georges Creek water had much lower concentrations of metals, iron and sulfate and a pH of about 7.0. The distribution of macrobenthos in Georges Creek showed the effects of both runoff from coal storage piles and periodic drought. Brillouin's diversity index values were low even in areas which did not dry. Densities of tubificid worms and chironomid larvae were very high above the coal storage areas where organic inputs were high. At all the rest of the sampling stations, macroinvertebrate densities were very low. Where coal pile runoff enters Georges Creek, it compounds the effects of periodic drought and further stresses the aquatic community.     

Behavioral risk and education: A united states case study

Summary Does educational achievement affect people's health-related behaviors? Differences in behavioral risk were found among 9,000 18 to 34 year old Americans surveyed for smoking, alcohol abuse, seat-belt-use, obesity, high blood pressure and physical activity. After controlling for sex, race/ethnicity and age, educational achievement was strongly associated with smoking and seat-belt use, and also with hypertension and obesity. New environmental health education programs in the USA are expected to reach the more educated, leading to enhanced health for most Americans, but not the less educated, resulting in a widening gap in American society.Dr Michael R. Greenberg is an Advisory Board member ofThe Environmentalist, he is Co-director of the Graduate Program in Public Health at Rutgers University and the University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School.     

Mercury cleanup: The commercial application of a new mercury removal/recovery technology

Efficient, economical treatment of mercury-contaminated soils and industrial wastes requires a treatment process that reduces mercury content to near background levels (<1 ppm) and recovers the removed mercury in pure recyclable form without producing liquid, solid, or gaseous secondary wastes. This article reviews the results achieved using a medium-temperature thermal desorption process developed and commercialized by Mercury Recovery Services, Inc. (MRS) that has successfully achieved these goals.     

An evaluation of resource inventory and monitoring program used in national forest planning

The National Forest Management Act (1976) specifies that multiresource inventories be conducted to provide baseline data for development and, later, monitoring of national forest management plans. This mandate entails the most ambitious and complex resource planning effort ever attempted. In this paper we evaluate the structure and use of current inventory-monitoring programs and recommend a framework for gathering data to improve national forest planning. Current national guidelines are general and provide only basic directions to forest-level planners. Forest inventories have traditionally concentrated on timber. Although these inventories are often well designed, the questions we are now asking about forest resources have outgrown these methods. Forest management is impeded by general confusion over definitions of resources and the interactions among them. We outline a simple classification scheme that centers on identification of basic ecosystem elements that can be readily measured. Furthermore, spatial and temporal scales must be considered in the design of inventory-monitoring programs. The concept of ecological indicators is reviewed, and caution is advised in their use. Inventory-monitoring programs should be goal-directed and based on as rigorous a statistical design as possible. We also review fundamental issues of variable selection, validation, and sampling bias. We conclude by developing a flexible inventory-monitoring program that is designed to provide information on individual characteristics of the environment, rather than being based on fixed definitions of resources.     

Large-scale constructed wetlands for nutrient removal from stormwater runoff: An everglades restoration project

The South Florida Water Management District (SFWMD) constructed a wetland south of Lake Okeechobee to begin the process of removing nutrients (especially phosphorus) from agricultural stormwater runoff entering the Everglades. The project, called the Everglades Nutrient Removal (ENR) project, is a prototype for larger, similarly constructed wetlands that the SFWMD will build as part of the Everglades restoration program. This innovative project is believed to be one of the largest agricultural stormwater cleanup projects in the United States, if not in the world. This publication describes the ENR project's design, construction, and proposed operation, as well as the proposed research program to be implemented over the next few years.     

Developing new environmental excellence programs: Lessons from epa's environmental leadership program

Interest in the concept—and implementation—of environmental excellence is at an all-time high. A wealth of examples from individual companies, trade associations, states, industry coalitions, and the federal government illustrate the growing acceptance by a wide range of stakeholders of a management systems approach to environmental issues. Perhaps nowhere is this more clear than in the collection of public comments submitted to EPA in response to its January 15, 1993, Federal Register notice, which proposed the creation of an Environmental Leadership Program (ELP). The authors, both of whom worked on the ELP, review these public comments and offer a set of “do's and don'ts” for organizations interested in establishing an environmental excellence program. In addition, the authors outline the Green Track proposal, a plan to structure an alternate regulatory pathway based on environmental excellence.     

SOCIAL IMPLICATIONS OF SEVERE SUSTAINED DROUGHT CASE STUDIES IN CALIFORNIA AND COLORADO1

ABSTRACT: Survey data collected in the San Joaquin Valley of southern California and the Grand Valley of western Colorado reveal that residents of both areas believe that a severe sustained drought is likely to occur within the next 20–25 years and that their communities would be seriously impacted by such an event. Although a severe sustained drought affecting the Colorado River Basin would cause major economic and social disruptions in these and other communities, residents express little support for water management alternatives that would require significant shifts in economic development activities or in water use and allocation patterns. In particular, residents of these areas express little support for strategies such as construction and growth moratoriums, mandatory water conservation programs, water transfers from low-to high-population areas, water marketing, or reallocations of water from agricultural to municipal/industrial uses. This rejection of water management strategies that would require a departure from “business as usual” with respect to water use and allocations severely restricts the capacity of these and similar communities to respond effectively should a severe sustained drought occur.     

Satisfaction with a performance appraisal system and appraisal discussion

Satisfaction with a performance appraisal system and the appraisal discussion was assessed by questionnaires administered to a random sample of managers and employees in a large multinational corporation. Stepwise regression and cross validation analyses were used to identify reliable linear composites for managers (n = 222) and employees (n = 368) on two dependent measures: overall experience with the appraisal system, and quality of the appraisal discussion. The results indicated differences in the aspects of the appraisal process which are related to satisfaction with the appraisal discussion, compared to satisfaction with the overall appraisal system. The results also indicated differences between managers' and employees' opinions regarding the appraisal system. Managers were found to be more satisfied than employees with most aspects of the appraisal system. And, the aspects of the appraisal system which were related to managers' and employees' satisfaction with the appraisal discussion were substantially different.