|
Spatial
Displays of South Florida Water Quality Data Environmental
Engineer prepared
for US
Department of the Interior Update: May 23, 2019 Total Phosphorus
Data Only Water Years
1990-2019: http://www.wwwalker.net/ever/sfwq/sfwq_1990-2019.kmz Original: March 31, 2017 Water Years
2008-2017: http://www.wwwalker.net/ever/sfwq/sfwq.kmz Video: https://www.youtube.com/watch?edit=vd&v=gPUR8P2lmtQ Documentation for March 31, 2017 Version This Google Earth layer displays grab-sample water quality data
collected in South Florida between Water Years 2008 and 2017 (May 2007 -
April 2017). Water Year 2017 values
are currently updated thru January 2017.
The data have been compiled from South Florida Water Management
District's DBHYDRO
database and research programs.
Sampling frequencies are generally monthly for marsh sites and
biweekly for canal sites. The
displays are intended to depict spatial variations in water quality, not to
reflect compliance with state or federal standards. For
purposes of displaying the data, monitoring sites are broadly categorized as
marsh sites or canal sites. Canal sites include data from canals, structures,
and pump stations. Marsh sites include
data from the Everglades Protection Area, Big Cypress, Lake Okeechobee, and
Florida Bay. Water quality data are paired with daily flow data at each
site. Flows are directly measured at
canal sites or taken from the nearest upstream or downstream location. While direct measurements of flow at marsh
sites are generally not available, pairing marsh water quality data with
corresponding basin outflows provides perspectives on temporal variations in
water quality related to flow. The
combined outflows from Lake Okeechobee are paired with Lake sites. The combined outflows from WCA-1, WCA-2A,
or WCA-3A are paired with marsh sites in the Water Conservation Areas. The
combined inflows across different sections of the L29 canal (S12A to S334)
are used for ENP marsh sites in Shark River Slough. A constant flow is assumed at Florida Bay
sites. Flows discharged from
structures or pump stations immediately upstream are used for marsh
transects. Water variables include nutrients (Total P, Total N, Total N/P
Ratio, Potassium, and Potassium/Total Phosphorus Ratio), inorganic chemistry
(Chlorides, Sulfate, Calcium), and field data (Temperature, pH, Specific
Conductance, Dissolved Oxygen Percent Saturation, Dissolved Oxygen as a
percent of DO-SSAC), and Alkaline Phosphatase. DO-SSAC is Florida
DEP’s Site-Specific Alternative Criterion for dissolved oxygen levels at
marsh sites in the Everglades Protection Area. The criterion adjusts for the impacts of
variations in water temperature and time of sample collection on DO
levels. The ratio is computed based upon
paired sample values for DO concentration, water temperature, and time-of-day,
then averaged across samples within each year. This is slightly different from the FDEP
compliance test, which averages the DO and DOSSAC separately within each year
before determining compliance. See
Florida's water quality standards. Water quality data for the 10-year period are summarized as
follows: ·
Geometric Means (GMs).
The long-term geometric mean is computed as the arithmetic mean of
yearly geometric means, as per Florida
DEP’s 4-Part test for tracking marsh levels relative to the 10-ppb
Phosphorus Criterion. While FDEP
screens the data for purposes of measuring compliance, all grab-sample data
collected at marsh sites are used here, regardless of flow, the number of
samples per year, or the distribution of samples between wet and dry
season. At canal sites, data
collected on days without flow are excluded.
Geometric means are computed only for variables that are typically
log-normally distributed (Total Phosphorus, Total Nitrogen, Total N/P ratio,
Total K/P ratio). Arithmetic means are
used for the other water quality variables. ·
Arithmetic Means (AMs).
The long-term arithmetic mean is computed as the arithmetic mean of
the yearly arithmetic means using all of the data at
marsh sites and data collected on dates with positive flow at canal
sites. ·
Flow-Weighted-Means (FWMs).
The long-term flow-weighted mean is computed directly from the paired
daily flow and grab-sample concentration data without summarizing by
year. While flow-weighting is not
typically done for marsh data, the FWMs are more heavily influenced by high
flow conditions when downstream transport is important. Since a constant flow is assumed at
Florida Bay sites, the computed AMs and FWMs are equal. The Google Earth interface is displayed below:
Folders
summarize data for specific water quality variables. Folders with average water depths on
sampling dates, average flows on sampling dates, and SFWMD watershed
boundaries (downloaded from DBHYDRO) are included. Sub-folders
display arithmetic means, geometric means, flow-weighted means, total number
of samples, number of years with data, and site labels. Double clicking displays the entire network
of sites. Single clicking maintains the current imagery and view. To focus on a particular
region, double-click on a sub-folder in the "Basin Views"
folder. Map symbols
are labeled with the site GM or AM (balloon) or FWM (balloon with dot in
center) values. Blue symbols represent marsh sites. Orange symbols represent canal sites. Click on a balloon to see station
information and dataset values. The height
of a balloon tail above ground is proportional to (Min (Conc, Cmax) - Cmin), where Cmax is the maximum value for scaling and Cmin is the minimum value for scaling. The parameter values are listed in the dataset
(click on a balloon). Cmin is set to 0 for all parameters except for pH (6 ) and temperature (18 deg-C). Cmax is set at a
value close to or above the maximum value in the dataset. Capping the maximum balloon height at Cmax reduces the impact of sites with extremely high
values and provides higher resolution of values in the low concentration
range. The actual AM, GM, or FWM values are displayed as text on the map. Use the
Google Earth navigation controls to adjust the views. Mouse left-click and drag
cursor to move. Mouse scroll to zoom in or out. Ctrl-Scroll to rotate.
Shift-Scroll to tilt. Double click on the folder to reset the view. Google Earth print format files are provided for creating maps
with legends. These can be downloaded
from here (save link as: geometric
or arithmetic mean layout, flow-weighted
mean layout ) and loaded via the Google Earth print interface. This shows Total Flow-Weighted Means using
the FWM print layout.
Please check the website for updates. For other displays of Everglades phosphorus data, see: Exploratory
Analysis of Everglades Flow & Phosphorus Dynamics , December, 2014 Trends in Total
Phosphorus Concentration and Flow at Monitoring Sites Within and Upstream of
Everglades National Park , September, 2014 |
