Home Introduction Study Area Methods & Procedures Estimation of Nutrient Loads & Water-Quality Analyses - Distribution - Cross-Section Surveys - Statistical Comparisons - Model Development Summary & Conclusions References PDF Version

Estimation Of Nutrient Loads And Water-Quality Analyses

Figure 1. Location of the east coast canal sites and subregions in Miami-Dade County [larger image].

Water samples were collected from the gated control structures at the east coast canal sites in Miami-Dade County (fig. 1) for the purpose of developing models that could be used to estimate nitrogen and phosphorus loads. Box plots were constructed (shown later) to show differences in the median concentration of the individual nutrient species at each site. Additionally, field measurements of selected water-quality constituents (specific conductance, pH, water temperature, and dissolved oxygen) were made at specific intervals to describe vertical and horizontal variability of an east coast canal site (S-22). Plots have been constructed for site S-22 (shown later) to determine whether total nitrogen and total phosphorus concentrations increase with depth.

The constituent load at any given time can be determined if the constituent concentration and the discharge at the time of sampling is known. The load is computed as follows:

where L is the constituent load, in short tons per day; C is the constituent concentration, in milligrams per liter; Q is discharge at time of sampling, in cubic feet per second; and 0.002697 is a conversion factor to short tons per day.