ISSN:1040-2381    

DOI:10.1080/07438148609354587

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:1040-2381    

DOI:10.1080/07438148609354588

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:1040-2381    

DOI:10.1080/07438148609354589

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:1040-2381    

DOI:10.1080/07438148609354590

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:1040-2381    

DOI:10.1080/07438148609354591

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

In 1984 the Delaware River Basin Commission and the National Park Service began a monitoring program to increase the frequency and areal extent of sampling within existing budget limitations. The goal of the program is to obtain water quality information on 120 miles of the Delaware River and 75 tributaries in a three-state area. This reach is included in the National Wild and Scenic Rivers System; recreation is intense. A variety of real and potential pollution sources exist. To maximize the available resources, a water quality screening approach was developed and put into practice via informal interagency cooperation. Parameters include rainfall, fecal bacteria, benthos diversity, and several chemical parameters. These are analyzed separately and compared between parameters and with adjacent watersheds. Experience has shown that the screening approach effectively assesses problems, sources of problems, and water quality management priorities. Small-scale research is also conducted and a feedback mechanism allows the program to adjust quickly to findings. The water quality screening approach applies to a variety of watershed and lake management situations and can augment traditional routine monitoring programs.

ISSN:1040-2381    

DOI:10.1080/07438148609354592

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Limnological studies undertaken on Chautauqua Lake, N.Y., between 1974 and 1983 indicated that lake water quality can be assessed by monitoring Secchi disk transparency and phytoplankton chlorophylla. These measurements of phytoplankton abundance were observed to vary from year to year depending on the amount of precipitation; high chlorophyllaand poor transparency correlated with high precipitation, presumably due to increased loading of nutrients to the lake. Comparison of the data collected between 1974 and 1983 with comparable measurements made in the 1930s revealed that Chautauqua Lake water quality has not been substantially altered over the last 50 years. Transparency and the occurrence of blue-green algae were similar, although diatoms may have been more abundant in the 1930s. The results of these limnological studies reinforce the concept that long-term monitoring of algal abundance and species composition can be an appropriate means of detecting changes in lake water quality.

ISSN:1040-2381    

DOI:10.1080/07438148609354593

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A method for computing phosphorus loadings from continuous stream discharge records and discrete water samples is presented. Because of the highly variable relationship between phosphorus concentrations and runoff discharges, loadings for runoff events with incomplete or no concentration data become difficult to compute. However, concentrations can be predicted from instantaneous discharge data using simple linear regression after separating the phosphorus data into the dissolved and particulate components. Dissolved phosphorus is stratified according to season when the ground is either frozen or not. Particulate phosphorus, because of its strong correlation to suspended sediment, is stratified according to the “event intensity” as determined by rainfall intensity and rate of rise of the stream hydrograph. The particulate data can be further stratified according to whether the sample was taken on the rise or fall (including peak) of the hydrograph. Field sampling recommendations are made based on the study findings.

ISSN:1040-2381    

DOI:10.1080/07438148609354594

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Public desires to fully understand the extent of hazardous waste contamination conflict with the reality of limited resources for data collection. Movement of groundwater plumes contaminated with organic chemicals from a landfill area toward Annabessacook Lake were documented in an EPA Remedial Investigation, but proof that chemicals had reached the lake remains elusive. Data deficiencies identified by Cobbossee Watershed District have produced monitoring refinements with more definitive results. EPA is presently selecting a cleanup strategy. Proposed massive expenditures for comprehensive cleanup activities cannot be justified on the basis of the limited lake data collected. Local and state agencies have made the unusual recommendation to delay immediate cleanup until further monitoring quantifies the problem. A phased cleanup approach has been proposed which would use monitoring in conjunction with negotiated “action levels” to initiate cleanup options. Final decisions by government and private interests are anticipated this year.

ISSN:1040-2381    

DOI:10.1080/07438148609354595

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Previous studies on lakes in northern Minnesota revealed elevated fish mercury concentrations. These results prompted fish consumption advisories on several lakes. As a followup to that work, fish fillet samples were collected for mercury analysis from 98 lakes in northern Minnesota from 1981 through 1983. Northern pike (Esox lucius) was picked as an indicator species because of its distribution throughout the region. Mercury concentrations ranged from 0.10 μg/g to 2.72 μg/g. This paper will focus on the relationship between the water chemistry of these lakes and the mercury concentration in a single size class of northern pike (50–63 cm). Correlation analysis (Spearman) revealed significant positive correlations between fish mercury and water measurements of aluminum and color and significant negative correlations between fish mercury and pH, alkalinity, and calcium. A multiregression procedure (SAS RSQUARE) revealed that the best multivariate model for predicting fish mercury concentrations, for this data set, included water aluminum, pH, and trophic status (expressed in terms of Carlson's TSI). This model will be used to identify lakes in Minnesota where future fish mercury studies should be focused.

ISSN:1040-2381    

DOI:10.1080/07438148609354596

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor