ASSESSMENT OF FUTURE WATER AVAILABILITY IN HUNZA
RIVER ORIGINATING FROM HIGHLY GLACIERISED KARAKORUM
MOUNTAINS USING SWAT HYDROLOGICAL MODEL
Qurat ul Ain Ahmad Global Change Impact Studies Centre (GCISC),
Islamabad, Pakistan
International Conference on Climate Change Innovation and
Resilience for Sustainable Livelihood
12-14 January 2015, Kathmandu, Nepal
OUTLINE
o Cryosphere of HKH Region and Major Challenges
o Water Resources of Pakistan
o Study Focus
o Methodology
o Results and implications
o Conclusion
Some facts related to Cryosphere of UIB
• Total Glacial Area…. = 15061.74 sq.km
• Est. total Ice Reserves..… = 2,174 Km3
• Total number of Glaciers…. = 11,413
Source: ICIMOD (2011)
Cryosphere of HKH region
Recent trends in global warming which are likely
to change the cryosphere dynamics, hydrological
cycles and atmospheric flows of the region
MAJOR RESEARCH CHALLENGES IN
HKH REGION
Understanding of Interaction between atmosphere and HKH Cryosphere
Monitoring of Glaciers to evaluate their response for assessment of future water
availability in rivers originating from HKH Mountains
Relative contribution of snow and ice melt in rivers
Accumulation and melting pattern of snow & ice
Development of system to forecast precipitation patterns
Development of knowledge based mechanism to reduce the risks posed by extreme
climatic events such as floods, droughts, GLOFs, Landslides etc.
Efficient use of water in all sectors by employing latest technologies, particularly
in agriculture sector
5
Source Finding
World Glacier Monitoring Service
Measurements taken over the last century clearly
reveal a general shrinkage of mountain glaciers on a global scale
Mason Inman (2010)
In Nature reports-climate
change
“The remote glaciers of the Himalayan mountains
have been a subject of much controversy, yet little
research” (Out of about 12000 to 15000 glaciers in
Himalaya and around 5000 in Karakorum, very
few have been measured on the ground to see if
they are losing or gaining mass)
“It is pretty clear that Himalayan glaciers have
been losing mass, with markedly greater loss in
the past decade than earlier” Graham Cogley, Geographer, Trent University Ontario
Dirk Scherler et al. (2011)
In Nature Geoscience (Effect of Debris cover)
Out of 42 studied glaciers in Karakoram region, 58% advancing/stable and 42% retreating. In all other regions (Himalaya, Hindukush, West Kunlun Shan), the studied glaciers are mostly retreating. Study has found that the debris cover has a significant influence on glacier terminus dynamics.
...Cont
Some Studies over HKH Glaciers Under
Changing Climate
6
Source Finding
Hewitt, 2005
Bishop et al., 2008
Hewitt, 2011
Copland et al., 2011
Dirk Scherler et al. (2011)
Gardelle et al., 2012
Sarikaya et al., 2012
Kääb et al., 2012
Janes and Bush 2012
Wiltshire, 2013
Cogley (2012) in Nature Geoscience
Stable/slightly advancing glaciers
“No ice lost in the Karakoram”
Karakoram cryosphere under changing climate
“Karakoram Anomaly”
GLACIERS AND DRAINAGE IN NORTHERN
PAKISTAN •Pakistan is an Agrarian Country whose
Economy is highly dependent on the
Agriculture Sector
•Bread Butter of 60% of Population depends
on Agriculture
•Share of Agriculture Sector to Country’s
Annual GDP is 24-25%
• Rainfall and Snow/Glacier melt are major
resources of fresh water in the Indus river flows
which is strongly correlated to winter
Precipitation and summer temperature.
• Total Glaciers: 5,218, Covered Area: 15,040
Sq. km, Total ice reserves: 2,738.5 km3,
Shyok, Shigar and Hunza are major tributaries
of Indus River and contain 83% of total ice
reserves of Pakistan
Pakistan’s Economy
PROBLEM STATEMENT IN MANAGING WATER
Growing Population/ decreasing per capita water availability
Expected Increased Variability in River Flows
Water Storage Capacity
Increasing Water Demand for Agriculture and Energy
Disregarded Water Quality
Environmental degradation
Water sharing with neighboring countries
Climate Change Concerns
Low response capacity (Financial Resources, Technology,
Institutional Capacity)
Uncertain Future Water Availability
8
Study Flow Chart/ Methodology
1
2
3
4
y = 0.0103x + 3.9447
∆T = 1.143 C
SD = 0.55013
Mean = 4.52
y = 0.0584x - 111.8
R² = 0.5036
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
19
00
19
05
19
10
19
15
19
20
19
25
19
30
19
35
19
40
19
45
19
50
19
55
19
60
19
65
19
70
19
75
19
80
19
85
19
90
19
95
20
00
20
05
20
10
Tem
per
atu
re (
Deg
ree
Cel
ciu
s)
y = 0.3844x - 336.71
∆P = 42.67 %
SD = 61.54038
Mean = 415.30
y = -0.3682x + 1159.1
R² = 0.0011
200
250
300
350
400
450
500
550
600
19
00
19
05
19
10
19
15
19
20
19
25
19
30
19
35
19
40
19
45
19
50
19
55
19
60
19
65
19
70
19
75
19
80
19
85
19
90
19
95
20
00
20
05
20
10
Pre
cip
itati
on
(m
m)
Trend of Annual Total Precipitation for UIB (1901-2012)
Trend of Annual Average Temperatures in UIB (1901-2012) using CRU Data Set
Climate Variability over Upper Indus Basin, Pakistan
Western River Flow Trends and Variability
Hunza River Flows (Historic)
Study Area & Data Used
Geographic Information of Hunza River Basin
River flow gauging station Dainyor Bridge
Latitude 35.5 - 37N
Longitude 74 - 76 E
Elevation of gauging station 1450 m
Drainage area 13,733 km2
Glacier-covered area 4688 km2
Glacier cover percentage 34 %
Mean elevation (computed from 4631 m
ASTER GDEM)
Area above 5000 m 32.5 %
No. of meteorological stations 3 (Installed by WAPDA)
Khunjerab Ziarat Naltar
4730 m 3669 m 2858 m
Data Description and Source
DEM ASTER DEM (30m) (http://asterweb.jpl.nasa.gov/gdem-wist.asp)
Soil FAO Harmonized World Soil Database (HWSD)
http://www.fao.org/nr/land/soils/harmonized-world-soil-database/download-data-only/en/
Land-use Originals at approximately 400 meter resolution
http://www.waterbase.org/download_data.html
Streams HYDRO1k stream data
http://eros.usgs.gov/#/Find_Data/Products_and_Data_Available/gtopo30/hydro
Basins Global River Basins (http://www.waterbase.org/download_data.html)
Rivers Rivers+Lake centerlines (V 1.4.0)
http://www.naturalearthdata.com/downloads/10m-physical-vectors/
DETAILS OF METEOROLOGICAL STATIONS & WEB LINKS
USED FOR PHYSICAL DATA
Name of
DCP
Stations
Elevation (masl) Geographical
Coordinates
Period of Record
Used
Naltar 2810 36.21N, 74.26E 1995-2007
Ziarat 3669 36.83N, 74.43E 1995-2007
Khunjrab 4730 36.85N, 75.4E 1995-2007
SOIL AND WATER ASSESSMENT TOOL (SWAT)
•SWAT model was developed by US Department
of Agriculture – Agriculture Research Service
(USDA-ARS)
•SWAT is a conceptual model that functions on a
continuous daily time step
•SWAT model predicts the influence of land
management practices on constituent yields from
a watershed
•In order to adequately simulate hydrologic
processes in a basin, the basin is divided into sub
basins referred to as hydrologic response units (H
RU’s) through which streams are routed.
•Each HRU is a unique combination of soil and
land use characteristics and are considered as
hydrologically homogeneous
•The model calculations are performed on a HRU
basis and flow and water quality variables are
routed from HRU to sub basin and subsequently
to the watershed outlet
Yes
Enter HRU/Sub basin command loop
Read or generate
Precipitation and Max/Min
Temperatures
Generate solar radiation,
Wind Speed and Humidity Compute Soil temperature
Compute Snow fall and Snow
melt
Rainfall +
Snowmelt
>0 Compute Surface
Runoff and
Infiltration
Surface
Runoff
>0
Compute Soil Water Routing, ET,
Crop Growth, Pond, Wetland
Balances, Ground Water Flow and
Height
Compute Peak, Rate,
Transmission losses, Sediment
Yield, Nutrient and Pesticide
Yield
Exit HRU/Sub basin command loop
Yes
SWAT MODEL EVALUATION (CALIBRATION AND VALIDATION)
R2 = 0.836
R2 = 0.846
Calibration Validation
FUTURE PROJECTIONS USING STATISTICAL
DOWNSCALING
CLIMATE PROJECTION OF DOWNSCALED HADCM3(A2)
(OBSERVED AND PROJECTED TEMPERATURE FOR 3 MET STATIONS)
Max
. Tem
per
ature
Observed Projected
Min
. Tem
per
ature
Khunjrab Naltar Ziarat
OBSERVED AND DOWNSCALED PROJECTED PRECIPITATION
AT LOCAL STATION POINT
Observed Projected
Projected Avg. precipitation of 3 stations
RESULTS FUTURE RUNOFF FOR F1, F2 AND F3
STATISTICS FOR CLIMATE & FLOWS PROJECTION
Sr. No. Tmax-m Tmin-m Tmax-R2 Tmin-R2 Pcp-m Pcp-R2
Naltar-Obs 0.028 0.0932 0.0234 0.4002 6.9703 0.0544
Ziarat-Obs 0.1399 0.1654 0.3718 0.4292 -0.9346 0.001
Khunjrab-Obs 0.0571 0.0683 0.1653 0.2525 0.6648 0.0116
Naltar-Pro 0.0083 0.0141 0.0943 0.2776 3.7175 0.1012
Ziarat-Pro 0.0134 0.0179 0.2066 0.3289 1.988 0.047
Khunjrab-Pro 0.005 0.0095 0.6581 0.1331 0.9079 0.1156
Sr. No. Slope Coeff. Of det. R2 T-stats Change
F1 (2010-2039 -2.608 0.5292 5.829 -78.24
F2 (2040-2069) 0.6383 0.0415 -0.099 19
F3 (2070-2099) 0.1145 0.0016 -0.1134 3.44
CONCLUSIONS
• Future downscaled GCM data of HadCM3 under IPCC SRES A2 scenario
gives increase in temperature and precipitation for the whole century with
slightly decreased Summer temperatures, and increased winter precipitation
• The historical data of Hunza River Flows shows a substantial decreasing
trend: about 39% decrease during 1966-2004
• Simulation results reveal continuation of the historical trend up to 2040 but
stabilization of flows thereafter.
• Quantatively, the annual flows decrease by about 63 % during F1 (with t-
stats of 5.8) and no significant change (t-statistics being about 0.1) during
the periods F2 and F3.
• Decreased stream flows with more temperature and precipitation is due to
increased rate of evapotranspiration
• More precipitation with less stream flows is an indicator of positive mass
balance
• Questions…
• Comments…
• Suggestions…
• Dr. Jaepil Cho (APCC) • Executive Director (GCISC) • WAPDA for providing Data • CCIRSL • TWAS for funding my Visit
ACKNOWLEDGEMENT
