Pollutant Concentration
Predicted Pollutant Concentration
Description
Pollutant concentrations have been derived from a series of linear mixed-effects models using spatial covariates. Regressions were performed on outfall stormwater measurements from the Washington State Department of Ecology's S8.D Municipal Stormwater Permit Outfall Data. The stormwater outfall data is available via an open-data api at: <https://data.wa.gov/Natural-Resources-Environment/Municipal-Stormwater-> Permit-Outfall-Data/d958-q2ci.
Heatmap layers have been developed for five constituents of concern:
- Total Copper
- Total Kjeldahl Nitrogen
- Total Phosphorus
- Total Suspended Solids
- Total Zinc
For more details on methodology, see the Water Quality Statistics documentation.
Units
Concentrations for all chemicals are provided in micrograms/liter (mcg/L) except for Total Suspended Solids, which is provided in milligrams/liter (mg/L).
Layer Access in Earth Engine
The javascript commands below can be used to access this layer within the Google Earth Engine Code Editor. A Google Earth Engine account is required.
// Import the layer data dictionary
var data = require('users/stormwaterheatmap/apps:data/public')
// To view data dictionary, print to the console:
print('Data:', data)
//Get this layer from the layer data dictionary:
var layer_name = data.pollutant_loading[LayerName]
Viewing
Individual objects contain all the info used in the stormwater heatmap. To add it to the map, add the layer object.
var display_image = layer_name.layer
Map.addLayer(display_image)
Analysis
To get the raw image data for analysis, access the eeObject key.
var raw_image = layer_name.layer.eeObject
Map.addLayer(raw_image,{},'Imperviousness')
Layer Full-Extent Download
Click the "download" link to initiate the download process. The data will download as a GeoTIFF file (the file size is listed beside the layer name) and a WGS 84 projection. The resolution is the finest available based on the source data.
The pollution concentration data represent estimated modeled values that can be used to evaluate relative values across the region.