SATELLITE MULTISPECTRAL COMPOSITIONAL MAPPING OF LAKE CYANOBACTERIAL BLOOMS AND LAND CHEMICAL COMPOUNDS
Presented at the Ohio Academy of Sciences, 2012.
6 ways Samsung’s Interactive Display powered by Android changes the classroom
Satellite Multispectral Compositional Mapping of Lake Blooms
1. Dr. Robert K. Vincent
Dept. of Geology
Bowling Green State University
rvincen@bgsu.edu
2. Besides the lone thermal infrared band, LANDSAT TM has
6 reflected sunlight spectral bands in the 0.4-2.5 µm
wavelength region with 30-m spatial resolution (each pixel
covers about 1/5th of an acre), yielding these advantages
over human observations from boats or docks:
◦ TM data can make observations as dense as 5 observations (or
measurements if a tested algorithm exists) per acre over an entire
body of water for most lakes (3 frames required for all of Lake
Erie).
◦ TM data can observe what humans cannot see, because 3 of its 6
spectral bands are outside the visible light wavelength range.
◦ TM looks ±3° from straight down (nadir), reducing surface (specular or glint)
reflection in calm water.
◦ TM data can be downloaded to the company’s computer within 24 hours of
overpass (every 16 days for one LANDSAT and every 8 days for 2 LANDSATs), and
the entire lake can be processed in a few hours.
Blue Water Satellite, Inc. has licensed 7 (one more being added)
algorithms for which BGSU has applied for patents thus far.
3. LBPC (Low Bloom Phycocyanin Content)
◦ Maps low blooms of cyanobacteria in water in the 2-17
µm/L (ppb) range, with rms error = 3.1 ppb
◦ Can map cyanobacteria blooms before they can be identified by a
human observer in a boat on the water (helps early mitigation)
HBPC (High Bloom Phycocyanin Content
◦ Maps high blooms of cyanobacteria in water in the 2-64
•m/L (ppb) range, with SE= 7.2 ppb
MC (Microcystin Content)
◦ Maps toxin Microcystin in high blooms of cyanobacteria in
water in 2-63 •m/L (ppb) range, and it has been correct on
45 of 47 water samples from 2 dates of collection, as to
whether MC was above or below the World Health
Organization sporting lake advisory limit of 20 •m/L (ppb)
4. Microcystin Toxin Measured in Water Samples Vs.
HBPC3RAT Algorithm (LANDSAT TM) Estimate of PC
on 25 Sept 2008
70
y = 0.514x - 17.133
60
R² = 0.8606
Microcystin Content ((•g/L)
50
40
30
Microcystin
20
Linear (Microcystin)
10
0
0 20 40 60 80 100 120 140 160
-10
-20
HBPC Algorithm Results for PC Content (•g/L)
5.
6. Red 90-150 µg/L
Orange 80- 89 •g/L
Yellow 60- 79 •g/L
Blue-Gr. 45- 59 •g/L
Blue 1 - 44 •g/L (in water)
D. Blue 0 (neg. numbers on land)
7.
8.
9. LRTP (Low-Range Total Phosphate in Water)
◦ Maps the amount of total phosphate in water in
range 9-100 µg/L (ppb); accuracy ±5 ppb from 9-33 ppb
HRTP (High-Range Total Phosphate in Water)
◦ Maps the amount of total phosphate in water in the range
100-700 •g/L (ppb); rms error = 69 ppb
TPL (Total Phosphate on Land)
◦ Maps the amount of total phosphorous on/in bare
soil in range 550-2500 mg/kg (ppm) with SE=531
ppm
10.
11. Fig. 5. Image showing the total P concentration (mg/kg) in surface soil samples of F34 (left side of the image) and
F11 (right side of the image) fields displayed as red (high P content) to Turquoise (low P content) obtained by
applying the P spectral ratio model to the LANDSAT 5 frame of May 20, 2005 which was used for developing the
model. Field near Oregon, OH; field on left had Class B sewage sludge injected hours earlier.
12. Tested algorithms pertaining to
cyanobacterial blooms currently exist that
employ LANDSAT TM data for mapping:
◦ Pigment content in surface waters (phycocyanin)
◦ Toxin content in surface waters (Microcystin)
◦ Nutrient content in surface waters (T. Phosphate)
◦ Nutrient content on bare soil (T. Phosphate)
◦ Others (Total Sulfate content in surface waters;
Copper and Sulfur contents in bare soils)
It is time to use satellite monitoring for
cyanobacterial blooms in lakes and streams.