Pav

2. 3. Geology and Soil
• The dominant rock types present in the
Subproject area include Phyllite, Schist,
Gneiss and Quartzite.
• The common soil types include Colluvial and
Residual soils.

3. Geology and Soil Type Along the Road
S.N Soil Type RockType Remarks
1 Colluvial and
Alluvial
Gneiss,Schist and
Quartzite/Phyllite.
Rocks are moderately to highly
weathered;Schist is completely
weathered at some places.
2 Colluvial and
Residual
Quartzite/Phyllite,Gneis
s,Phyllite and Schist.
Rocks are moderately to highly
weathered;Schist is completely
weathered at some places.
3 Colluvial and
Residual
Quartzite, Intercalation
of Quartzite and
Phyllite.
Rocks are moderately to highly
weathered; Phyllite is
completely weathered.
4 Colluvial and
Residual
Phyllite,Slate and
Schist.
Phyllite is highly weathered.

4. 4. Climate and Rainfall
• The climate of the Subproject area varies
from sub tropical to temperate.
• The maximum monthly average rainfall
(1997-2006) was found to be 485.8 mm in
July.
• The minimum rainfall of 7.8 mm occurred in
November.

5. Rainfall Pattern in Okhaldhunga from 1997 to
2006 .
10-year-average rainfall
600
500
400
300
200
100
0
Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec
Month

6. B. BIOLOGICAL ENVIRONMENT
1. Vegetation
• Due to the altitudinal variation, the major forest are found in the Subproject area
are Tropical forest with the dominancy of Shorea robusta; Subtropical Broad-
leaved forest with the dominancy of Schima wallichii and Castanopsis indica;
Subtropical Pine forest with the lower temperate mixed broad-leaved forest.
• All the forests are in growing stage with scattered plantation of saplings of Alnus,
Macaranga and Pinus along the alignment of the road.
2. Non Timber Forest Product (NTFP)
• The major NTFP species found in the Subproject area are Swertia chirayita
(Chiraito), Centella asiatica (Ghodtapre) and Acorus calamus (Bojho).
3. Protected Vegetation
• The protected vegetation found in the Subproject area contains five tree species
and one herb species. However, none of the species is affected by the upgrading
activities of the road. The vegetable of subproject area are: champ, khair,okhar,
sal and chiraito.
4. Community Forest
• The road alignment passes through five community forests.

7. Community Forest (CF) in the Subproject Area
S.N. Chainage NameofCF VDC
Area
(Ha.)
1. 39+000to41+200 KalikaDeviMahilaCF Okhaldhunga-4 4.95
2. 24+000to27+000 BhimsenMahakaliCF Ketuke-4 81.86
3. 24+000to27+000 BhumethanMangalbareCF Ketuke-3 128.5
4. 12+000to15+000 MahadevsthanCF
Manebhanjyang-
6
438.7
5. 6+000to9+000 ThumkiDumkiCF Thakle5,6,7&8 382.2