Analysis of Trends in the Chemistry of Surface Waters of the United States. Annual Report for NAPAP Projects E1-8 and E2-11. Final Report for IAG No. DW 89930347-01-0. Appendix III. Trend List. Volume 2

摘要

This volume contains a complete list of trend analyses on all 6117 stations in ACID for which adequate data are available. Adequate data were defined as at least 10 measurements on the variable of interest representing at least five years. The list includes both upstream and downstream stations, including 583 of the 4164 stations that were randomly sampled from STORET and that have alkalinity values above 500 mu eq/l or pH above 7.5. Simple linear regression on time was done for H exp + , alkalinity, SO sub 4 , Ca, Ca + Mg, Ca + Mg + Na, and Ca + Mg + Na + K (all expressed in mu eq/l). Time was expressed as a Julian date converted to units of years, and the trend coefficients are thus in units of mu eq/l/year. The results are in a sense raw data. The main report (volume I) discusses the shortcomings of this type of analysis and attempts to interpret the results for New England plus New York using a regional approach rather than a station by station approach. 1 figure, 1 table. (ERA citation 09:038450)