Simplified methodology for stream discharge calculation of Kunur river in Burdwan District.

STREAM DISCHARGE CALCULATION (A) IN Cumt/hr=B x C Cumt/hr

B- Calculation of Cross sectional area of a stream canal in sqmt.

                  C- Calculation of Stream Velocity in Mt/hr

1.       Calculation of Cross sectional area of a stream canal  in sqmt.(B)

   i.           Measurement of width - This may be measured through a measuring tape or a measured bamboo. Width of stream of Kunur river  is  28.5 mt near Purbatati IV lift irrigation sub-project, latitude 23.54159 and Longitude 87.60875.

                 

Bamboo length is 15ft 4 inch= 4.67 (D)mt; 

  width of stream canal is 6 times of bamboo 

                                                                      length plus 0.45 mt.

        

               Width of stream canal = (6 times x D) + 0.45 mt.=28.5 mt (approx.)

      ii.                Divide width of the stream canal into 10 nos. of interval. 1 to 9^th interval consist of            3mt  length, 10^th interval consist 1.5 mt length

     iii.        Measure the depth of each interval

Table: Length and depth of each interval of the stream.

Sl.No.	No of interval	Length of interval in mt.	Depth of interval in mt
1	1	3	0.355
2	2	3	0.419
3	3	3	0.482
4	4	3	0.533
5	5	3	0.863
6	6	3	0.533
7	7	3	0.457
8	8	3	0.355
9	9	3	0.152
10	10	1.5	0(approx.)

Schematic Diagram of cross section of stream of river Kunur.

iv.                 Calculation of Cross sectional area of a stream canal

Sl.no.	Area of Cross Section	Area breakup in sq.mt.
1	1	1/2 x 0.355 x 1.5=0.266
2	2	1/2 x 0.508 x 12=3.05
3	3	1/2 x 0.508 x   9=2.286
4	4	1/2 x 0.102 x 3=0.153
5	5	1/2 x 0.152 x 3=0.228
6	6	0.355 x 3=1.065
7	7	0.355 x 24=8.52
Total		15.568

2.                                                                   2 . Calculation of Stream Velocity (C)

                             i.               Mark a  start point parallel to river canal

ii.                   On the surface of the stream float an empty plastic water bottle 

        iii.                  Follow the flow of the bottle for 1 to 2 minutes

                       

iv.                 After 1 to 2 minutes mark  endpoint point parallel to river canal

                v.                   Measure the distance travelled by the empty water bottle after 1 to 2 minutes

       vi.                 Calculate the distance travelled by the  empty water bottle per hour

Calculation of Stream velocity of the Kunur river near Purbatati IV lift irrigation sub-project, latitude 23.54159 and Longitude 87.60875 is :-

·         Bottle travelled 111 ft in 2 minutes;

·         Hence, it would travel =111 X 30 ft in a hr. or 3330 ft/hr or 1014.98 mt/hr (C).

AVAILABLE STREAM DISCHARGE O(A) IN CUM/hr

A =B x C cum/hr

A = 15.568 sqmt. x 1014.98 mt/hr

A =15801.20 Cumt/hr
                                          
                                              (Courtesy: Sajal Bhowmick, Env. Specialist, WBADMIP)

1.