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Title: Emerald Lake Watershed study: Introduction and site description

Abstract

The Emerald Lake Watershed study was organized to investigate the effects of acidic deposition on high-elevation watersheds and surface waters of the Sierra Nevada, California. Some of the results of this comprehensive study of aquatic and terrestrial ecosystems at a small, headwater basin are presented in four papers in this series. The watershed study site is in Sequoia National Park, on the western slope of the Sierra Nevada. This glacial cirque is located in the upper Marble Fork of the Kaweah River. This 120-ha watershed ranges from Alta Peak (3,416 m) down to Emerald Lake (2,400 m). Most of the watershed surface area is exposed granite and granodiorite rocks, with limited coverage (about 20%) by thin, acidic soils. The hydrology of the basin is dominated by snowmelt runoff during March-June. Emerald Lake, a glacial tarn, is 2.72 ha in area, with a maximum depth of 10.5 m. Surface waters are poorly buffered and dominated by calcium and bicarbonate. Most of the yearly precipitation falls as dilute snow (pH5.2-5.4), with acidic rain storms sampled during May-October.

Authors:
 [1]
  1. (California Air Resources Board, Sacramento (United States))
Publication Date:
OSTI Identifier:
5715895
Resource Type:
Journal Article
Resource Relation:
Journal Name: Water Resources Research; (United States); Journal Volume: 27:7
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; ACID RAIN; RESEARCH PROGRAMS; ACID NEUTRALIZING CAPACITY; AQUATIC ECOSYSTEMS; CALIFORNIA; HYDROLOGY; MOUNTAINS; RUNOFF; SEASONAL VARIATIONS; SNOW; SURFACE WATERS; TERRESTRIAL ECOSYSTEMS; WATERSHEDS; ATMOSPHERIC PRECIPITATIONS; CHEMISTRY; DEVELOPED COUNTRIES; ECOSYSTEMS; ENVIRONMENTAL TRANSPORT; MASS TRANSFER; NORTH AMERICA; RAIN; USA; VARIATIONS; WATER CHEMISTRY; 540320* - Environment, Aquatic- Chemicals Monitoring & Transport- (1990-); 540120 - Environment, Atmospheric- Chemicals Monitoring & Transport- (1990-)

Citation Formats

Tonnessen, K.A. Emerald Lake Watershed study: Introduction and site description. United States: N. p., 1991. Web. doi:10.1029/91WR00587.
Tonnessen, K.A. Emerald Lake Watershed study: Introduction and site description. United States. doi:10.1029/91WR00587.
Tonnessen, K.A. Mon . "Emerald Lake Watershed study: Introduction and site description". United States. doi:10.1029/91WR00587.
@article{osti_5715895,
title = {Emerald Lake Watershed study: Introduction and site description},
author = {Tonnessen, K.A.},
abstractNote = {The Emerald Lake Watershed study was organized to investigate the effects of acidic deposition on high-elevation watersheds and surface waters of the Sierra Nevada, California. Some of the results of this comprehensive study of aquatic and terrestrial ecosystems at a small, headwater basin are presented in four papers in this series. The watershed study site is in Sequoia National Park, on the western slope of the Sierra Nevada. This glacial cirque is located in the upper Marble Fork of the Kaweah River. This 120-ha watershed ranges from Alta Peak (3,416 m) down to Emerald Lake (2,400 m). Most of the watershed surface area is exposed granite and granodiorite rocks, with limited coverage (about 20%) by thin, acidic soils. The hydrology of the basin is dominated by snowmelt runoff during March-June. Emerald Lake, a glacial tarn, is 2.72 ha in area, with a maximum depth of 10.5 m. Surface waters are poorly buffered and dominated by calcium and bicarbonate. Most of the yearly precipitation falls as dilute snow (pH5.2-5.4), with acidic rain storms sampled during May-October.},
doi = {10.1029/91WR00587},
journal = {Water Resources Research; (United States)},
number = ,
volume = 27:7,
place = {United States},
year = {Mon Jul 01 00:00:00 EDT 1991},
month = {Mon Jul 01 00:00:00 EDT 1991}
}
  • As part of the Integrated Watershed Study in the vicinity of Emerald Lake, Sequoia National Park, investigators conducted baseline monitoring of benthic invertebrates in the inflow streams and the outflow stream. During summer 1986 they carried out a series of acidification experiments in artificial stream channels located in the drainage of the Marble Fork of the Kaweah River. Twelve channels (2.4 m x 20 cm x 20 cm) were stocked with natural substrates, algae and invertebrates. In the treatment channels the pH was reduced to 4.6 and 5.2, using a mixture of nitric and sulfuric acids. Measurements of benthic densities,more » drift rates and algal densities were made before, during and after each acid treatment of 8 hours duration. Diatom populations declined in the acidified channels, while other periphyton species actually increased with the treatment.« less
  • The present study was designed to establish quantitative relationships between lake air-equilibrated pH, alkalinity, and diatoms occurring in the surface sediments in high-elevation Sierra Nevada Lakes. These relationships provided the necessary information to develop predictive equations relating lake pH to the composition of surface-sediment diatom assemblages in 27 study lakes. Using the Hustedt diatom pH classification system, Index B of Renberg and Hellberg, and multiple linear regression analysis, two equations were developed which predict lake pH from the relative abundance of sediment diatoms occurring in each of four diatom pH groupings.
  • The Lake Jackson watershed study was undertaken to quantify changes in water quality and geochemical exports resulting from urbanization within the 11,900 hectare watershed of a recreational lake in north Florida. Three subbasins of 430, 611, and 792 hectares in size and otherwise similar in all respects except land-use were instrumented for intensive hydrologic and chemical monitoring during a two-year period (June 1973--May 1976). Two of these subbasins offered considerable contrast in major land use: rapidly developing urban versus stable forested-agricultural. The third subbasin was intermediate between these extremes of land use. The streams draining the subbasins were generally intermittentmore » with respect to flow and thus major emphasis was placed on characterizing storm events. Hydrologic records for each water sampling station were studied and water samples were collected both manually and by automatic discrete samplers. Constituents measured included suspended solids, dissolved solids, chloride, dissolved silicon, and dissolved nutrients (nitrogen and phosphorus). The data obtained in this study are being used to identify and explore the hydrochemical consequences of urbanization on a small drainage basin scale.« less
  • In order to better understand the implications of acid deposition in watershed systems in the Sierra Nevada, the California Air Resources Board (CARB) initiated an intensive integrated watershed study at Emerald Lake in Sequoia National Park. The comprehensive nature of the data obtained from these studies provided an opportunity to develop a quantitative description of how watershed characteristics and inputs to the watershed influence within-watershed fluxes, chemical composition of streams and lakes, and, therefore, biotic processes. Two different but closely-related modeling approaches were followed. In the first, the emphasis was placed on the development of systems-theoretic models. In the secondmore » approach, development of a compartmental model was undertaken. The systems-theoretic effort results in simple time-series models that allow the consideration of the stochastic properties of model errors. The compartmental model (the University of Arizona Alpine Hydrochemical Model (AHM)) is a comprehensive and detailed description of the various interacting physical and chemical processes occurring on the watershed.« less
  • This report describes the results of field work conducted at Emerald Lake in Sequoia National Park during the period of 1983-88, with an emphasis on the effects of acid deposition on a high-elevation lake in the Sierra Nevada. Time-series data were collected for major ions, nutrients, trace metals, chlorophyll, zooplankton and zoobenthos. Mass balances were calculated for major solutes in the lake, including analysis of the inflows and major solutes in the lake, including analysis of the inflows and outflow from the lake. The ecology and population dynamics of the resident population of brook trout were studied in detail. Biologicalmore » surveys indicated the presence of the Pacific tree frog in small ponds in the vicinity of Emerald Lake. Experimental acidification of large bags in the lake was used to develop dose-response relationships for the major zooplankton species, especially Daphnia. The conclusion of the research to date is that Emerald Lake is not currently showing serious chemical or biological effects of acidification. Acid-sensitive animals are found in the lake and associated streams. The surface waters of the Emerald Basin are extremely dilute and ANC-generating processes in the lake are small compared to that of the watershed. Acidic episodes have been recorded. If these episodes were to increase, the surface waters and the biological populations could be readily affected.« less