EFFECTS OF DIVERSIONS ON THE NORTH AMERICAN GREAT LAKES1

ABSTRACT: Water level fluctuations of the Great Lakes often have created regional controversies among the states and Canadian provinces that share this vast resource. Even though the 100-year range of their water levels is only four to five feet, episodes of high and low Great Lakes water levels have been a recurring problem throughout the twentieth century. The possibility of increased diversion and consumptive use has exacerbated the existing conflicts over how to manage this water resource. A research project evaluated the effects of interbasin diversion on the Great Lakes system and on the industries that depend on the maintenance of historical water levels, namely hydropower and commercial navigation. The simulation approach employed in this research and some of the important findings are presented. The approach is similar to that used in recent government studies of Great Lakes water level regulation. Several significant modifications were made specifically addressing the diversion issue. Aggregate annual impacts to hydropower and shipping resulting from a diversion of 10,000 cubic feet per second were found to vary from 60 to 100 million dollars. Increases in impacts as a function of diversion rate are nonlinear for the navigation industry.     

NONPARAMETRIC TESTS FOR TREND DETECTION IN WATER QUALITY TIME SERIES1

ABSTRACT: A review of nonparametric tests for trend leads to the conclusion that Mann-Whitney, Spearman, and Kendall tests are the best choice for trend detection in water quality time series. Recently these tests have been adapted to account for dependence and seasonality in such series (Lettenmaier, 1976; Hirsch, et al., 1972; Hirsch and Slack, 1984). For monotonic trends, a procedure allowing to select the pertinent tests considering the characteristics of time series is proposed and the practical limitations of the tests are also brought out. This procedure has been applied to identify the appropriate trend detection test for the time series of nine water quality parameters at Lake Laflamme (Québec). When a time series can be tested with the Mann-Whitney, Kendall, Spearman, or Lettenmaier (1976) test, the number of observations required to detect trends of a given magnitude, for selected significance and power levels can be calculated with the power function of the t test. When the test proposed by Hirsch, et al. (1984), Hirsch and Slack (1984), or Farrell (1980) need to be used, the number of observations can only be estimated approximately from the results of empirical power studies.     

And keep on looking: A film to reduce pedestrian crashes among 9 to 12 year olds

A pedestrian safety education film titled And Keep on Looking and aimed at children ages 9 to 12 was evaluated in several cities. The results showed an increase in safe street crossing knowledge among 9- to 12-year-old Connecticut children who viewed the film, and some improvement in safe street crossing behavior among 9- to 12-year-old Seattle, Washington, children. Crash reduction was assessed in a 2-year, citywide field test conducted in Milwaukee. The field test indicated a crash reduction of more than 20% for 9- to 12-year-old children in Milwaukee compared with children in areas surrounding Milwaukee and children in comparison cities.     

Riparian buffers and potentially unstable ground

The spatial coincidence between riparian buffers of various widths and extents and potentially unstable ground was quantified using a physically based model for shallow landslide initiation and GIS for two watersheds on the Olympic Peninsula, Washington, USA. The proportion of the potentially unstable ground in each watershed within riparian buffers is a function of both buffer width and the extent of the stream channel network being buffered. While current buffers required by Washington State cover less than 5% of the potentially unstable ground, buffering all stream channels in these watersheds with 100-m buffers covered 75%–90% of the potentially unstable areas. Our analyses further show that: (1) riparian buffers are not efficient mechanisms for protecting potentially unstable ground, and (2) identifying potentially unstable ground using a physically based model should prove more effective for designing methods to reduce shallow landsliding hazards than relying on extensive buffer zones along stream channels.     

We should allow dissection of animals

The focus of the paper is the ethical issues associated with the practice of dissecting animals in lower level college biology classes. Several arguments against dissection are explored. Furthermore, the issue is examined from the point of view of the instructor's academic freedom and the point of view of a student's moral autonomy. It is argued that even though the arguments against dissection fail, it is very important to respect the moral autonomy of students who oppose the practice. Often this can be accomplished in a manner that is consistent with academic freedom and good science education.     

THE LAW OF THE COLORADO RIVER: COPING WITH SEVERE SUSTAINED DROUGHT1

ABSTRACT: The waters of the Colorado River are divided among seven states according to a complex ‘Law of the River’ drawn from interstate compacts, international treaties, statutes, and regulations. The Law of the River creates certain priorities among the states and the Republic of Mexico, and in the event of a severe sustained drought, the Law of the River dictates the distribution of water and operation of the elaborate reservoir system. Earlier work indicated that there is remarkable resilience in the system for established uses of water in the Lower Basin of the Colorado River. This work shows, based on an application of the Law of the River using computer modeling of operations of facilities on the Colorado River, that there may be serious environmental consequences and related legal restraints on how the water is used in times of shortage and that the existing legal and institutional framework governing the Colorado River does not adequately address all the issues that would be raised in a severe sustained drought. Several possible legal options for dealing with drought in the context of the Law of the River are identified.     

FREQUENCY-DURATION ANALYSIS OF DISSOLVED-OXYGEN CONCENTRATIONS IN TWO SOUTHWESTERN WISCONSIN STREAMS1

ABSTRACT: Historically, dissolved-oxygen (DO) data have been collected in the same manner as other water-quality constituents, typically at infrequent intervals as a grab sample or an instantaneous meter reading. Recent years have seen an increase in continuous water-quality monitoring with electronic dataloggers. This new technique requires new approaches in the statistical analysis of the continuous record. This paper presents an application of frequency-duration analysis to the continuous DO records of a cold and a warm water stream in rural southwestern Wisconsin. This method offers a quick, concise way to summarize large time-series data bases in an easily interpretable manner. Even though the two streams had similar mean DO concentrations, frequency-duration analyses showed distinct differences in their DO-concentration regime. This type of analysis also may be useful in relating DO concentrations to biological effects and in predicting low DO occurrences.     

DIFFERENTIAL ACCUMULATION OF SELENIUM AMONG AXIAL MUSCLE,REPRODUCTIVE AND LIVER TISSUES OF FOUR WARMWATER FISH SPECIES1

Bluegill (Lepotmis macrochirus), largemouth bass (Micropterus salmoides), white catfish (Ictalurus catus), and channel catfish (Ictalurus punctatus), collected from an electric power plant cooling reservoir and a municipal water supply reservoir near Roxboro, North Carolina, were analyzed for selenium concentrations in axial muscle, reproductive and liver tissues. Fishes from the municipal water reservoir had lower selenium concentrations (≤0.2-2.1 μg/g - wet weight) than found in the cooling reservoir fishes (1.6-70.0 μg/g - wet weight) but similar distributions of concentrations among the tissues was evident. Selenium was differentially accumulated, with higher concentrations in liver tissues (0.7-70.0 μg/g - wet weight), followed by female reproductive tissues (0.7-25.0 μg/g - wet weight), axial muscle tissues (≤0.2-23.0 μg/g - wet weight) and male reproductive tissues (0.2-7.2 μg/g - wet weight).