Carrying Capacity Study of Teesta Basin in Sikkim - Affected ...

The Teesta drainage has been resulted from both physical and
cultural environments in the course of geoecological adjustment of those
Himalayan geocomplex like climate, structure, vegetation, soil,
topography or other terrain factors determining the rapidity of runoff. It
relates to geomorphology including hydrology, and the flow
characteristics in the Teesta and tributary streams especially after
storms, human intervention over the mountain and piedmont plain. The
human intervention mainly concerns with the utilization of water for
irrigation, hydel power generation, fishery development, and the various
arrangements which in turn obstruct the normal flow of water in terms of
constructing embankments of canal and reservoir, human settlements,
roads, railway and like. However, this drainage of different types
especially of surface drainage with varying depth, surface spread,
frequency or mobility at different seasons is closely associated with
irrigation work.
The Teesta basin or catchment may be divided into sub-
catchments of decreasing size on the basis of both quantitative and
qualitative considering the interrelated factors like gradient, infiltration
capacity, surface roughness etc. The higher mountainous terrain with
varying topography has determined rapidity of runoff and character of
flow maxima and minima in the upper Teesta and tributary streams
particularly after severe (local) storms. Most of the upper granite gneiss
surfaces mainly made of impermeable materials with few pondage
pockets are typified by a steeply sloping topography. The relatively
smooth-surface-segments being covered with little vegetation (relating to
forest clearance) are found to have given rapid runoff and high sudden
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CISMHE