Relationships of Watershed Climate and Geochemical Processes to Trophic Characteristics in Texas Reservoirs
Date
1992-05
Authors
Ground, Ted Alan
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Abstract
Gibbs' classification of surface waters was used to investigate relationships between watershed geochemical climatic processes and trophic characteristics in 80 Texas reservoirs. Three classes of reservoirs were identified by using Gibbs' graph comparing total dissolved solids (TDS) with the ratio of sodium to calcium plus sodium. These classes were delineated into West, Central, and East geographic groups, corresponding with high, intermediate, and low TDS ranges, respectively. Alkalinity, pH, conductivity, calcium, sulfate, and chloride data further distinguished these classes. Significant differences were found in the amount and form of nutrients, organic carbon, chlorophyll a, suspended solids, and phytoplankton counts. East reservoirs ranked highest in nutrients, chlorophyll, diatoms, and green algae. Central reservoirs were highest in inorganic nitrogen. West reservoirs ranked lowest in inorganic nitrogen and highest in cyanobacteria. Morphometry, hydrology, and human impacts vary among individual reservoirs, but comparisons indicated that differences in these factors between regions were insufficient to explain trophic differences. Calcite precipitation, inorganic nitrogen, iron, pH, and sulfate are characteristics which influence trophic differences between watershed types.
Description
Keywords
reservoirs, water
Citation
Ground, T.A. (1992). Relationships of watershed climate and geochemical processes to trophic characteristics in Texas reservoirs (Unpublished thesis). Southwest Texas State University, San Marcos, Texas.