4
RESULT AND DISCUSSION
Table 1 summarizes the spearman correlations between
cobalt production and Normalized Difference Vegetation
Index (NDVI) metrics for the five selected mining loca-
tions over the 23-year period. The estimated correlation
coefficients offer valuable insights into the relationships
between variables in different mining operations. Positive
correlation coefficients (0 to 1) suggest that as one variable
increases, the other tends to increase, however, a negative
coefficient (–1 to 0) indicate that as one variable increases,
the other tends to decrease. As noted earlier the NDVI is
used as a proxy for vegetation health and biodiversity. The
estimated summary of the correlations for the mines is pre-
sented in Table 2.
As shown in Table 1 and considering the correlation
with Mean NDVI (R1), negative correlations could be
observed across the Mutanda, Etoile, Kasulo, and Ruashi
mines. This suggest an increased cobalt production is asso-
ciated with declining average vegetation health (sites may
experience more vegetation loss with increased production).
This trend suggests significant environmental impacts from
mining, such as deforestation or land degradation. This
behavior could also be inferred from Figures 2–5 for Etoile,
Kasulo and Ruashi and Mutanda mines, respectively.
While moderate to weak negative impacts on over-
all vegetation health could be seen in the studied mines,
a stronger negative correlation (e.g., Ruashi: –0.7588,
Figure 4) indicates that these sites may experience more
Table 1. Summary of estimated spearman correlations for the cobalt mine locations from 2000 to 2023
Mine Location
Mutanda Kamoto Etoile Kasulo Ruashi
R1 –0.076907768 0.150693864 –0.331438903 –0.162026425 –0.758874498
R2 0.414110758 0.31165208 0.722997811 –0.056954719 0.050090469
Note: For all cobalt mines from 2000 to 2023, R1 =Correlation between Cobalt Production and the Mean NDVI, R2 =Correlation
between cobalt production and the standard deviation NDVI
Figure 2. Time series comparison of cobalt production data for Etoile mine with the mean and standard deviation of the
NDVI
RESULT AND DISCUSSION
Table 1 summarizes the spearman correlations between
cobalt production and Normalized Difference Vegetation
Index (NDVI) metrics for the five selected mining loca-
tions over the 23-year period. The estimated correlation
coefficients offer valuable insights into the relationships
between variables in different mining operations. Positive
correlation coefficients (0 to 1) suggest that as one variable
increases, the other tends to increase, however, a negative
coefficient (–1 to 0) indicate that as one variable increases,
the other tends to decrease. As noted earlier the NDVI is
used as a proxy for vegetation health and biodiversity. The
estimated summary of the correlations for the mines is pre-
sented in Table 2.
As shown in Table 1 and considering the correlation
with Mean NDVI (R1), negative correlations could be
observed across the Mutanda, Etoile, Kasulo, and Ruashi
mines. This suggest an increased cobalt production is asso-
ciated with declining average vegetation health (sites may
experience more vegetation loss with increased production).
This trend suggests significant environmental impacts from
mining, such as deforestation or land degradation. This
behavior could also be inferred from Figures 2–5 for Etoile,
Kasulo and Ruashi and Mutanda mines, respectively.
While moderate to weak negative impacts on over-
all vegetation health could be seen in the studied mines,
a stronger negative correlation (e.g., Ruashi: –0.7588,
Figure 4) indicates that these sites may experience more
Table 1. Summary of estimated spearman correlations for the cobalt mine locations from 2000 to 2023
Mine Location
Mutanda Kamoto Etoile Kasulo Ruashi
R1 –0.076907768 0.150693864 –0.331438903 –0.162026425 –0.758874498
R2 0.414110758 0.31165208 0.722997811 –0.056954719 0.050090469
Note: For all cobalt mines from 2000 to 2023, R1 =Correlation between Cobalt Production and the Mean NDVI, R2 =Correlation
between cobalt production and the standard deviation NDVI
Figure 2. Time series comparison of cobalt production data for Etoile mine with the mean and standard deviation of the
NDVI