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Surface Water Study Design

LTEN Basic-fixed Sites

Surface-water quality is monitored at two types of sites, basic-fixed sites and intensive-fixed sites, according to the frequency of the sampling. Basic-fixed sites are sampled on a regular basis, usually monthly, for two years during the 3-year high-intensity phase. Intensive-fixed sites are monitored more frequently for at least 1 year to characterize short-term variations of water quality. Both types of sites are used to monitor water- quality constituents, such as basic field properties, major ions, nutrients, and pesticides. Monitoring sites were selected to describe water-quality conditions in relation to important environmental settings and land uses in the study unit. Click on the pictures below for more information on each LTEN basic-fixed site. NOTE: Hester Creek and Flint River are both basic-fixed and intensive-fixed sites.

Map showing location of LTEN fixed sites

Basic-fixed or intensive-fixed sites are further classified as either indicator or integrator sites. Indicator sites represent relatively homogeneous and usually small basins associated with environmental settings, such as a specific land use that is considered to be important for understanding water-quality in the study unit. Integrator sites are established at downstream points in large drainage basins that incorporate complex combinations of land-use settings. Water quality at integrator sites reflects the effects of multiple land uses and transport in the basin.

Synoptic surface-water sampling can be used to address a selected issue in one river basin or to provide greater spatial coverage and allow investigators to assess whether basic- fixed or intensive-fixed sites are representative of streams throughout the study unit. Synoptic surface-water sampling involves short-term investigations of specific water-quality conditions at numerous sites during selected hydrologic periods, such as periods of low streamflow.

Last modified: Tue Jul 20 10:12:11 1999