Faculty began working immediately on a new section of our existing math placement test that would focus on the preparation students would need to succeed in statistics and also developed a ...quantitative literacy course that both matches the student learning outcomes of our general education program and provides focused preparation for further study in statistics.\n Because each of these initiatives came from the statistics group and were not mandated, they were widely embraced. Because the project to increase student success in these two math courses was undertaken as part of a state-level strategic planning process, it started with specific targets by which the improvement would be considered successful.
Critical loads are defined here as the highest deposition of strong acid anions (principally sulfate and nitrate) in surface waters that will not cause harmful biological effects on populations, such ...as declines in or extinctions of fish. This analysis focuses on sulfate deposition because in glaciated regions sulfate is conservative in soils, whereas nitrate is biologically cycled. Sulfate also is the dominant anion in acidic deposition and in most acidic lakes. This analysis which is derived from work sponsored by the Nordic council, represents the first evaluation of certain data available from Norway and the eastern United States with emphasizes data from Scandinavia.
As part of the Eastern Lake Survey, data on 26 chemical parameters were measured for 768 lakes in the north eastern U.S.A., including all of the New England states together with parts of N.Y., Pa., ...and N.J. A summary of the data obtained is presented in tables and graphs. The results were analysed to examine relationships between physical and chemical variables that might influence the response of the lakes to acid deposition or other perturbations. The data supported the hypothesis that regional lake acidification had occurred in northeastern U.S.A. (see preceding abstract).
In 1983, the U.S. EPA initiated a National Surface Water Survey, including both a national lake survey and a national stream survey. The present chemical status of surface waters in U.S.A. in regions ...susceptible to the effects of acid deposition was determined, temporal and spatial variability in aquatic chemistry assessed, and long-term temporal trends in surface water chemistry and biology quantified. The national lake survey included a survey of lakes in both western and eastern U.S.A. The principal features of the first phase of the eastern lake survey are described and regional estimates of the chemical status of lakes obtained in this stage are presented. There are 37 references.
As part of the Eastern Lakes Survey in U.S.A. (see preceding abstract), a survey was carried out on 592 lakes in northern Minn., Wis., and Mich., selected statistically from over 8000 lakes in this ...area. The survey was designed to quantify the number of lakes, with surface area greater than 4 ha, that were acidic or that had low acid-neutralizing capacity. The data are summarized in tables and graphs, and discussed for each sub-region. The results supported the hypothesis that some lakes in the upper Midwest U.S.A. had been acidified by acid deposition.
The Thousand Lake Survey was conducted in Norway in the fall of 1986 to determine the chemical status of lakes in areas sensitive to acidic deposition. The survey was also designed to detect possible ...changes in water quality as a follow-up to extensive regional surveys which were conducted in 1974/75. In large areas of southern Norway receiving acidic precipitation thousands of lakes and streams are acidic (ANC <0). Large areas elsewhere in Norway contain lakes with low concentrations of base cations. These areas would also be expected to contain acidic lakes if they receive acidic loadings equivalent to those in southernmost Norway. The pH of lakes in southern Norway has changed little from 1974/75 to 1986. Sulfate concentrations are significantly lower today in the most affected lakes in southernmost and eastern Norway, corresponding to reductions in emissions, but are still elevated. Nitrate concentrations in most of the lakes in Sørlandet have, however, doubled on average over the same period, while no significant changes have occurred in the rest of southern Norway. In the lakes with higher concentrations of nitrate in 1986, aluminum concentrations are also higher. At present, about 70 percent of the lakes sampled in southern Norway have lost all of their bicarbonate buffering capacity. With a 30-percent reduction from present levels of SO4in lakes, this percentage should decline to about 55 percent and with a 50-percent reduction about 45 percent of the lakes will be without bicarbonate buffering.
Acidic lakes sampled by regional surveys in southern Norway had low concentrations of total organic carbon (TOC); 60 per cent had less than 2 mg TOC. There was no direct relationship between pH and ...TOC. The effect of dissociated strong acids on acidity was examined. The anion deficit (calculated from a comparison of the sums of measured and anions) was proportional to TOC in data from a 1000 lakes. Strong acid concentrations were a function of base cation, excess sulphate, TOC and nitrate concentrations. In southern Norway the contribution of organic anions was less than 4 per cent for any pH range. Lake water TOC decreased with lake elevation. All lakes above 900 m had less than 2 mg TOC per litre.
PDF
