Environmental Assessment
Volume B-4.2
Mine
Fauna
Ambatovy Project
217
January 2006
Table 4.2-5 Impact (ha) on Habitats as a Result of Project-Generated Noise
Within the Local Study Area
Noise Range
Habitat Type
Baseline
(ha)
Area Impacted
(ha)
% Indirect Habitat
Loss
>55 dBA
(a)
azonal
1,380
-32
-2.3
transitional
1,489
-61
-4.1
zonal
12,527
-112
-0.9
ephemeral ponds
5
0
0
marsh
1,114
0
0
marsh edge
23
0
0
river/water
13
0
0
other
(b)
6,134
-1
-<0.1
45 to 55 dBA
(c)
azonal
1,380
-73
-5.3
transitional
1,489
-150
-10.1
zonal
12,527
-350
-2.8
ephemeral ponds
5
-<1
-1.6
marsh
1,114
0
0
marsh edge
231
0
0
river/water
13
0
0
other
(b)
6,134
-1
-<0.1
total
azonal
1,380
-105
-7.6
transitional
1,489
-211
-14.2
zonal
12,527
-462
-3.7
ephemeral ponds
5
-<1
-1.6
marsh
1,114
0
0
marsh edge
231
0
0
river/water
13
0
0
other
(b)
6,134
-2
-<0.1
(a)
Noise levels above daytime World Bank maximum levels for people (The World Bank Group 1999).
(b)
Includes pasture, rice paddies, eucalyptus woodlots, slash and burn areas, and villages.
(c)
Range between nighttime and daytime World Bank maximum levels for people.
Dust Effects
The estimated aerial extent of dust exceeding a concentration level of
20 micrograms/m
3
is 1,118 ha (5% of the mine LSA) after removing all direct
effects as a result of site clearing. The 20 micrograms/m
3
guideline was used as a
conservative measure and was based on vegetation effects reported in out-of-
country studies (see Volume B, Section 4.1 for full discussion).
Zonal forests will be most affected by dust based on areal extent (853 ha; 4% of
the mine LSA). However, a greater proportion of the azonal (6%; 77 ha) and
