Environmental Assessment
Volume B-3.1
Mine
Topography and Geomorphology
Ambatovy Project
20
January 2006
closure is considered low because of the benefits of reclamation; the existing
landscape contains steep, rolling topography that is not greatly different than the
altered mine topography, given the successful implementation of mitigations
including erosion control and slope stability engineering.
Slopes of mining features, both during mining and after reclamation, will fall
within the natural range of variation of slopes existing in the area. However, the
orientation, regularity and diversity of slopes will change, and on a local basis the
topographic changes will be very noticeable, with the potential to affect local
biological systems and human use of the land in the long term.
An overall residual impact classification for topography and geomorphology for
each phase of the project is presented in Table 3.1-3.
Table 3.1-3 Residual Impact Classification for Topography and Geomorphology
Phase
Direction Magnitude Geographic
Extent
Duration Reversibility Frequency Environmental
Consequence
Key Question TG-1
What Effect Will the Mine Have on Topography and Geomorphology?
construction negative
low
local
short-
term
no
medium
negligible
operations
negative
moderate
local
medium-
term
no
high
low
closure
negative
low
local
long-
term
no
low
low
Prediction Confidence
The baseline status of topography in the LSA is well understood, and detailed
information about the future landscape of the mine area has been made available
through closure planning. However, impact ratings are also dependent on the
success of the mitigations proposed, including erosion control and slope stability
engineering under challenging conditions. Overall, the prediction confidence for
this assessment is considered medium.
Monitoring
No monitoring is proposed specifically for topography and geomorphology.
Monitoring of the effectiveness of erosion control measures, slope stability and
reclamation success are described in Volume B, Section 6.
