acid mine drainage analysis of the samarco mine tragedy in...
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Total Suspended Matter - Mouth of Rio DoceLandsat 8 OLI: Path 215 Row 73 & 74
41 Days Post Disaster
● Unsurprisingly, there was an extreme increase in TSM concentrations following the disaster
● The concentration of sediment before the disaster (Figure 3) is 5 times less than the concentration of sediment after the disaster
Acid Mine Drainage Analysis of the Samarco Mine Tragedy in BrazilMiranda Schrader, Lucas Ryder, Andrew Saunders, Charles Sharpe
[email protected], [email protected], [email protected], [email protected]
On November 5th, 2015, the Fundão Dam failed in Minas Gerais, Brazil, releasing thestorage tailings pond for an open pit iron mine run by Samarco Mineração. Somewherebetween 55 and 60 million cubic meters of water and tailings sludge flooded the nearbycities of Bento Rodriguez and Paracatu, proceeding down the Rio Doce out to the riverdelta at Regência, and into the Atlantic Ocean.
The coast of Regência is home to the Reserva Biológica Comboios, a protected nestingground for loggerhead and leatherback sea turtles. Just north is the Abrolhos MarineProtected Area, one of the most biodiverse areas in the Atlantic Ocean.
The Rio Doce is severely impacted by the consequences of this dam failure, and now someof the richest, most diverse regions of Brazil’s coast are threatened by substantialsedimentation, acid drainage, and anoxic conditions. The effects will likely remain fordecades and accumulate up the food chain, while riverine, estuarine and marineecosystems will likely lose diversity and functionality.
We’ve presented a series of images that show the expansion of the sediment plume,indicating where settling and deposition are the most significant. This demonstrates thedirection of the ocean currents, which indicates what coastal areas and biological reservesare threatened.
Introduction
● Mosaicked Path 215 Row 73 & 74 of Landsat 8 OLI together
● Generated a cloud mask using density slices in ENVI using Band 4
● Calculated the Total Suspended Material (TSM) of each image using Mao et al., (2012)
● Analyzed previous findings of suspended material values in order to estimate the
different TSM concentrations for the density slice
● Constructed an Arbitrary profile from the river mouth outwards to observe the relationship between TSM concentration and distance from the river mouth
● Magnitude of the sediment released in the ocean has threatened the protected
habitat as well as water, food and economic resources
● Combination of the dangers of mining and current regulations, mean the
monitoring process needs to be reassessed on a major scale
● Sediment is depositing directly offshore, with large amounts settling along the
Reserva Comboios coast to the south (see Figure 1), and measurable quantities
drifting north, towards the Abrolhos Marine Sanctuary
Conclusions
Results
Before and After - Mouth of Rio DoceLandsat 8 OLI: Path 215 Row 73 & 74
R:4 G:3 B2
10 Months Before Disaster 25 Days Post Disaster
Methods
References
Mao, Z., J. Chen, D. Pan , B. Tao, Q. Zhu (2012). A regional remote sensing algorithm
for total suspended matter in the East China Sea. Remote Sensing of the Environment.
124, 819–831.
Total Suspended Material
Future Work● The next step for monitoring is to measure the effects these metal contaminants
are having in these regions, and develop an assessment of the full scope of the
damage to be used for both current damages and future regulation.
Reserva Comboios
Figure 2: Note that the plume shape has not changed too much, but the color and the spectral properties did
Figure 1: Image of river mouth before disaster. Note the biological reserve south of the river mouth
Figure 6: Line of arbitrary profile starting at river mouth going outwards
Figure 3: Image taken Jan. 30, 2015 of Rio Doce river mouth. Shows the concentration of material is non-existent in the ocean near the mouth. The deeper water does not represent the material accurately
Figure 7: Graph showing the concentration (mg/L) of TSM following the arbitrary profile
Figure 4:Image taken Nov. 30, 2015. The black marks across the image is the mask that was created for the clouds present in the image. It shows the suspended material is leaving the river and moving closer to the biological reserve
Figure 5:Taken December 16, 2015. Shows that the concentration of material has increased and moved toward the biological reserve
Resuspension of sediment
Plume from disaster
● Figure 7 shows that in 10 months prior to the event the TSM is staying the same with a small increase as it is leaving the river mouth
● 25 days and 41 days following the event the TSM values are exceptionally high toward the mouth of the river and are decreasing by distance
● The graph shows that 25 days post disaster the Red TSM values are much higher, but 41 days post disaster there is lower TSM values but more sediment
10 Months Before Disaster
Clouds
A
B
C
A: Mouth of river
B
C: End of transect 25 Days Post Disaster