anita khadka
TRANSCRIPT
ALTERATION IN SNOW MELT DRIVEN FLOW REGIME IN
CLIMATE CHANGE SCENARIO
Anita Khadka, L. P. Devkota, R. B. Kayastha Nepal Development Research Institute
Precipitation
Temperature
SCA
DDF Lapse rate Critical
Temp Runoff Coeff
Recession Coeff
RCA Time Lag
SRM Model
MODEL
Calibration & Runoff
Simulation
Runoff in Climate Change
Scenario
Temperature
Precipitation
PRECIS: ECHAM05 HadCM3
(2031-2060)
STUDY AREA
Basin Area (Km2) 5187
Area in Nepal 55%
Areal Length, km 140
Area > 5000 m 1970
SCA in Km2 692.31 (13 %)
SCA > 5000 m (%) 27.50
No. of Glacial Lakes 29
Elevation Range, m 545 – 7938
No. of Elevation Zones
11
Basin Characteristics – Sunkoshi
RESULTS
Temperature
10
15
20
25
Tem
pe
ratu
re ,
°C
Dhulikhel PanchkhalStations (trend)
ECHAM05 (°C/year)
HadCM3 (°C/year)
Panchkhal 0.047 0.042
Dhulikhel 0.047 0.043
15
17
19
21
23
25
203
0
203
1
203
2
203
3
203
4
203
5
203
6
203
7
203
8
203
9
204
0
204
1
204
2
204
3
204
4
204
5
204
6
204
7
204
8
204
9
205
0
205
1
205
2
205
3
205
4
205
5
205
6
205
7
205
8
205
9
206
0
Tem
pe
ratu
re ,
°C
Panchkhal_E Panchkhal _H Dhulikhel_H Dhulikhel_E
Historic
Projected
HYDROMETEOROLOGICAL DIAGONOSTIC
PRECIPITATION
y = 28.963x + 2761.9
y = 19.646x + 2818.8
2000
2500
3000
3500
4000
4500
20
31
20
32
20
33
20
34
20
35
20
36
20
37
20
38
20
39
20
40
20
41
20
42
20
43
20
44
20
45
20
46
20
47
20
48
20
49
20
50
20
51
20
52
20
53
20
54
20
55
20
56
20
57
20
58
20
59
20
60
Pre
cip
itat
ion
, mm
ECHAM HadCM3
Projected
y = 23.456x + 2511.2
0
500
1000
1500
2000
2500
3000
3500
4000
4500
Pre
cip
itat
ion
, mm
Historic
Discharge
y = -2.5113x + 274.35
0
50
100
150
200
250
300
350
Dis
char
ge, m
3/s
0
10
20
30
40
50
60
70
800
200
400
600
800
1000
1200
20
00
20
00
20
01
20
01
20
01
20
02
20
02
20
03
20
03
20
03
20
04
20
04
20
05
20
05
20
06
20
06
20
06
20
07
20
07
20
08
20
08
20
08
Pre
cip
itat
ion
, mm
Dis
char
ge, m
3/s
Average ppt Mesured Computed
0
500
1000
1500
2000
2500
2000 2001 2002 2003 2004 2005 2006 2007 2008
Dis
char
ge,m
3/s
Measured
Computed
SIMULATION RESULTS Calibration Year: 2001 NSE: 0.88 Dv: 7.32
On average NSE: 0.81 Dv: 4.74
SNOW MELT RESULTS
0
100
200
300
400
500
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
ECHAM HadCM3
00-08 41-50 51-60 31-40
Season % contribution Average 6.41 Winter 21.17
Pre-monsoon 14.87 Monsoon 4.28
Post-monsoon 19.53
ECHAM05 HadCM3 10.09 9.14
29.07 20.95
18.91 18.27
6.85 6.39
20.52 19.59
Baseline 2030-2060 (av)
RUNOFF
y = 1.4974x + 161.39
y = 1.3246x + 163.51 100
130
160
190
220
250
20
31
20
32
20
33
20
34
20
35
20
36
20
37
20
38
20
39
20
40
20
41
20
42
20
43
20
44
20
45
20
46
20
47
20
48
20
49
20
50
20
51
20
52
20
53
20
54
20
55
20
56
20
57
20
58
20
59
20
60
Flo
w in
m3
/s
ECHAM HadCM3
Season 2031-2040 2041-2050 2051-2060
ECHAM HadCM3 ECHAM HadCM3 ECHAM HadCM3
Average -9.83 -10.25 1.38 2.44 7.33 5.49
Winter -0.92 -3.10 3.56 10.40 5.41 8.10
Pre-monsoon 2.85 -4.75 19.41 5.60 34.18 8.85
Monsoon -12.99 -12.04 -0.78 -4.41 4.54 3.18
Post-monsoon -1.78 -6.21 4.27 42.06 12.50 17.58
PERCENTAGE CHANGE IN FLOW
RUNOFF RESPONSE– PROJECTED PERIOD
0
100
200
300
400
500
600
700
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Dis
char
ge, m
3/s
00-08
31-40
41-50
51-60
0
100
200
300
400
500
600
700
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Dis
char
ge, m
3/s
00-0831-4041-5051-60
Had
CM
3
ECH
AM
05
RUNOFF RESPONSE– PROJECTED PERIOD
Decade ECHAM05 HadCM3
Qmax N Qmax N
2031-2060 2384.53 41 2171.76 31
2031-2040 2000.17 11 1759.63 7
2041-2050 2384.53 17 1736.07 9
2051-2060 2023.42 13 2171.76 15
0
500
1000
1500
2000
2500
3000
2031 2033 2035 2037 2039 2041 2043 2045 2047 2049 2051 2053 2055 2057 2059
Dis
chag
e, m
3/s
ECHAMHadCM3Peak Q
FREQUENCY & MAGNITUDE OF PEAK FLOWS Qmax in baseline = 1195.8m3/s
CONCLUSION
The daily discharge is efficiently simulated by SRM model in Sunkoshi basin
Gradual increase in snow melt contribution follows the pattern of increasing temperature.
Changes in precipitation is correlated to variation in runoff (also peaks) generated in the basin.