Lingza - Ministry of Power

37
Preliminary Feasibility Report
Lingza HE Project (3 x 40 MW)
and relative humidity at Dikchu from Jan 1998 to Dec 2001 is enclosed as Annexure-5.1
and annual maximum and minimum temperature from 1998 to 2001 is given in Table
5.1.
Month
& Year
Table 5-1
Temperature And Humidity Data At Dikchu
Maximum
Temp o C
Minimum Temp
o C
Max. Relative
Humidity %
Min.
Relative
Humidity
1998 38.0 7.0 99.0 89.0
1999 39.0 6.0 99.0 90.0
2000 39.0 7.0 97.0 85.0
2001 31.0 11.0 97.0 90.0
Overall 39.0 6.0 99.0 85.0
5.2.4 Precipitation Characterstics
In the Teesta basin the southwest monsoon normally sets in the third week of May and
withdraws in the second week of October. The major portion of the catchment being hilly
and the river flowing in steep gradient, heavy rains in the upper and middle catchments
has an immediate effect of rendering the plains to flash floods.
Sh. B.Biswas and C.V.V Bhadram in their paper titled “A study of major rainstorms of
Teesta Basin” and published in Mausam (1984), have studied the rainfall distribution,
major rainstorms and their associated synoptic situations over the catchment based on 22
years data (1960-81). The entire Teesta catchment extending from its origin in north upto
the Indo Bangladesh border has been considered. On the basis of the rainfall distrib ution,
the Teesta catchment has been divided into three parts viz. upper, middle & lower. The
average annual rainfall is 1328 mm, 2619 mm & 3289 mm for the upper, middle and
%