Use of remote sensing in monitoring algal blooms in

inland water bodies

Anabel A. Lamaro

alamaro@conae.gov.aranalamaro@fcnym.unlp.edu

.ar

Fortaleza 1- 12 November 2010

A process where water bodies receive excess nutrients that stimulate excessive plant growth

EUTROPHICATION

CONSEQUENCESCAUSES

Excessive intake of nutrients P and N from point and diffuse sources.

Massive development of algae and cyanobacteria.

Low transparency

Fish kills

Presence of bad odors

Decrease in the aesthetic quality of the resource

Increased water treatment costs

Health risks

General

PurposeTo developed a methodology for monitoring algal blooms from different satellite data

analysis.

In situ

Data

Radiometric Data

5 measurements per point (average).

2 minutes on each point.

Height of 1.5-2 m. and perpendicular to the

surface.

Radiometer calibration.

Suspended

SolidsSecchi disk Water Surface

Temperature

Limnological parametersChlorophyll a

Phytoplankton

counting

•Landsat 5 TM y 7 ETM+, ASTER images

•Source: CONAE catalog, USGS catalog

Processing Geometric correction

Radiometric

correction

Atmospheric

correction

Digital

Data

Río Tercero Reservoir

Studied

AreasCórdoba province

Multiple Uses: • Recreation.

• Thermonuclear plant cooling.

San Roque Reservoir

• Flood Control.

• Water supply for the city of Córdoba.

• Electricity generation

• Recreation.

Multiple Uses:

Ln Secchi: 3.398527 - 0.130421 * Rad B2Obtained Model

r: - 0.962629

p: 0.000508

Standard Error: 0.3897628

n: 7

Secchi Disk vs. Band 2 radiance

R²: 0.926Model

ValidationR² adjusted: 0.911

(meters)

0.25-11.1-22.1-3>3

Río Tercero Reservoir

Historical Data

Results

Water Surface Temperature

Thermal bands Landsat 7 ETM+

Marzo 2000

Agosto 2000

Archive images (± 3 days)

Radiometric data

Digital data

Limnological data

Historical data (since

1998)

Historical and actual data

San Roque Reservoir

Field sampling synchronized with the satellite pass (January-

March 2009)

January 30th ,2009

March 20th,2009

Water surface conditions

P3 P5

P6

March 20th ,2009

98%

87% 85%

13%

15%

2%

January 30th, 2009

P6

3%

97%

49%

51%

P3

74%

26%

P5

Ceratium sp.

Cyanobacteria

Diatoms

Relative abundance of dominant species calculated by biovolumen

Preliminary

results

400-500 nm

500-590 nm

590-700 nm

700- 1300 nm

Analysis of field spectroradiometer curve

Chlorophyll reflectance

Chlorophyll absortion

Chlorophyll reflectance

3%

97%

Site P6

Ceratium sp.

Cyanobacteria

Comparison Radiance curve vs. Relative

Abundance

Laboratory culture

March 20th, 2009

Obtained Model

r: 0.97

p: 0.000001Standard Error: 0.32

n: 7

R2: 0.94

Ln chlrophyll: 26,49 – 0.44 Rad B2 -0.64 Rad B3 – 1.72 Rad B4

In situ Chlorophyll

Est

imate

d

Chlo

rop

hyll

Estimated: March 11st , 2000Measured: March 13rd, 2000

Correlation between limnological parameters and digital data

Estimated chlorophyll a

400

50

225

Chlorophyll a concentration

• We are working with water treatment company for the future application of these methodologies in the Rio de la Plata estuary.• Oil spill monitoring in ocean water, near offshore platforms using RADAR images.

To incorporate products of sea surface temperature, ocean color and others (from AVHRR, SeaWifs, Modis, Meris) to help to identify:

Marine currentsThermal fronts Turbidity Phytoplankton (blooms or HAB’s)Sources of pollution

IN A NEAR FUTUREFor Fisheries Research and

Development…

ACTUAL WORKS

• Water Quality Monitoring in Sectors of Uruguay River and in inland water bodies (i.e Ramsar sites, reserves, protected areas).

Thank you!