The annual temperature varies from maximum 31˚ c in summer to minimum 0˚ c in
winter. The relative humidity use to be more than 90% during rainy season. Due
to high rainfall and humidity earth material is weathered very fast in the area.
Soils vary from loamy to clayey with a thick layer of humus at the top. In the
valley area black and reddish soil is found. Soil acidity ranges from medium to
high.
EXISTING LAND USE
Land use and
type of management applied to each site explain, to a large extent, the
occurrence of the erosion processes (Sanchez et.al.2002). Earlier studies shows
that there has been conspicuous land use change in the Himalaya as consequence
of population increase and pressure on forest based resources (Rai and Sharma
1998). Thus, a visual interpretation of IRS 1C LISS III FCC and topographical
map on 1:50,000 scales is made to delineate land use categories supported by
field verification. The identified main land use categories are agriculture,
settlement and forest (Fig 3). A brief description of each identified categories
is given as below:
The plain area of valley is utilized for wet rice cultivation. Kitchen gardens
are very fertile due to continuous application of domestic manure which is used
for growing vegetables. The slopes of the adjacent hills in the vicinity of the
wet rice-fields are used for rain fed agriculture which includes the production
of maize, millet and variety of vegetables. Forest area mainly consists of
bamboo and pine trees. In this area people cultivate medium sized straight-
stemmed bamboo in close proximity to their villages. Pine is a splendid tree
used for timber and firewood purpose. It is grown in the lower slopes of nearby
settlement. Most of the bamboo groves are also having scattered pine trees. When
pine trees attain height, bamboo do not flourish in the shade of their wide
canopy. Besides bamboo and pine, there are number of fruit trees like small
cherry, peach, small pear and greenish, bitter apple which are planted in
groves, gardens, paths and lanes, burial ground and close to houses. Large
number of evergreen as well as deciduous species like hollock, jutuli, tita sopa,
hillika, dhuna, borpat, nahar, udal, gonsari, makrisal, bogipoma, khokan, etc.
is found in the area. The proportions of evergreen species are more than the
deciduous species mainly due to favorable climatic conditions in the area. Plain
area of valley is used for agriculture and the slightly elevated areas in the
vicinity of flat land are used as settlement. Because of high density of
population houses are constructed very closely, mainly built by wooden piles and
bamboo. Since long, this area consists seven large villages namely, Hong, Hari,
Biila (Reru, Tajang and Kalung), Dutta, Hiija, Mudang-Tage and Bamin-Michi. But
due to rapid growth of population (27,000 approx. Census-2001), five more
villages are created viz. Siiro, Lempya, Biirii, Nenchachaya and Siibe
separating from Hong, Tajang, Mudang-Tage, Dutta & Hiija and Bamin-Michi
respectively.
Observation
In comparison to the other parts, the Eastern
Himalaya receives heavy rainfall during monsoon. The total rainfall (Fig. 4) is
recorded in the study area is 19166 mm, out of which 54.05% is received during
monsoon (16th May to 15th Sept). The total wet and dry
days (Fig. 5) during monsoon are 64 and 56 respectively with the maximum
continuous seven rainy days. Very less rainfall is received with dry days of 54
from (16th Nov. to 15th Aug).
Table
1.
Rainfall
