Inter-linkage case study in Pakistan Snow and glaciermelt runoff - - PowerPoint PPT Presentation

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7 th GEOSS Asia Pacific Symposium GEOSS AWCI Parallel Session: 26-28 May, 2014, Tokyo, Japan Inter-linkage case study in Pakistan Snow and glaciermelt runoff modeling in Upper Indus Basin of Pakistan Maheswor SHRESTHA *Researcher, Department

SLIDE 1

Snow and glaciermelt runoff modeling in Upper Indus Basin of Pakistan

Maheswor SHRESTHA *Researcher, Department of Civil Engineering, University of Tokyo, JAPAN

7th GEOSS Asia Pacific Symposium

GEOSS AWCI Parallel Session:

26-28 May, 2014, Tokyo, Japan

Inter-linkage case study in Pakistan

SLIDE 2

Indus Basin - Resources Nexus

Indu ndus Water ter Trea eaty ty 1960 1960 Source: WAPDA

Snow/Glacier

Source: Rasul, PMD

SLIDE 3

Indus Basin - Resources Nexus

Snow/Glacier : Upper Indus Climate Change: How the equilibrium of this nexus will be affected ? Rainfall : Middle-Lower Indus

SLIDE 4

Modeling system

Which model?

Tropical – Arctic, Dry – Wet, Low-High elevation Variety of Landuse Land Use and Land Cover Map of Indus Basin (Cheema and Bastiaanssen, 2012)

Physics Based Distributed Hydrological Model

Rainfall induced flow (Land/Snow/Glacier/Forest) Snowmelt induced flow (Land/Glacier/Forest) Glacier melt induced flow Combination of All Snow/Glacier-Soil-Vegetation- Atmosphere-Transfer (SSVAT) schemes in land surface and hydrologic models

SLIDE 5

Hydrological Model

Water and Energy budget based distributed hydrological model with improved snow and glacier schemes (WEB-DHM-S)

Shrestha et al., 2010, 2012, 2013 One layer Snow physics Empirical albedo

Snow over Bare Land

Soil Snow /water Rsw αc.Rsw (αc,δc,εc ) δc.Rsw αsδcRsw Rlw εcσTc

(1-εc)Rlw εcσTc

Canopy Tc

SW transmittance

σTsn(Z3)

Snow

Snow over Forest region Clean Glacier Debris Covered Glacier Clean/Debris Covered Glacier Glaciers Covered with Snow

SLIDE 6

Upper Indus Basin (200700 km2)

Grid size: 1 km

# 6

82° 82° 80° 80° 78° 78° 76° 76° 74° 74° 72° 72° 38° 38° 36° 36° 34° 34° 32° 32° 30° 30°

Pakistan India China

Indus River

Upper Indus Basin

Tarbela Dam

DEM

High : 7647 Low : 406

Karakoram Sub-basins HUNZA Himalaya Glacier : About 22000 km2

SLIDE 7

# 7

Data Set

Gauge Data – WAPDA

Max/Min air temperature Precipitation Total solar radiation

APHRODITE gridded precipitation data (25 km) Global Land Data Assimilation System (GLDAS) data (25 km)

Specific Humidity Shortwave radiation Wind speed

Glacier Cover data

ICIMOD (Bajracharya et al., 2011)

Hunza Basin (13733 km2)

SLIDE 8

Hunza Basin

Snow/Glacier Cover Area

# 8

Snow/Glacier State simulation (2001-2002)

January 1 May 9 July 12 September 14

1 2 3 4 5 6

(b) Areal extent of snow cover

0.0 0.2 0.4 0.6 0.8 1.0 8-Oct 24-Oct 9-Nov 25-Nov 11-Dec 27-Dec 9-Jan 25-Jan 10-Feb 26-Feb 13-Mar 29-Mar 14-Apr 30-Apr 16-May 1-Jun 17-Jun 3-Jul 19-Jul 4-Aug 20-Aug 5-Sep 21-Sep

Snow Cover Area (in fraction)

MODIS MODEL Absolute BIAS

L Sno Clea Sno De Sno

(a) Spatial distribution of snow cover area (2003-2004)

MODIS Model MODIS Model November 9 January 1 March 5 May 9 July 11 September 13 Legend: Land, Snow, Cloud

SLIDE 9

Hunza Basin

Daily Discharge

# 9

Snow & glacier melt contribution = 80-85 % (50-60% snowmelt) Rainfall contribution = 15-20% Calibration Validation

SLIDE 10

Upper Indus Basin (200700 km2)

Grid size: 1 km

# 10

82° 82° 80° 80° 78° 78° 76° 76° 74° 74° 72° 72° 38° 38° 36° 36° 34° 34° 32° 32° 30° 30°

Pakistan India China

Indus River

Upper Indus Basin

Tarbela Dam

 Simulation results follows the seasonal variation of snow cover represented by the MODIS  However, large discrepancies were observed while performing pixel-pixel analysis, mainly due to the uncertainty in spatial distribution of APHRODITE precipitation. Snow Cover Area

SLIDE 11

Indus Basin (200700 km2)

Daily Discharge

# 11

Long-term simulation 1980-2012 is

ngoing with the use of JRA55 dataset.

Daily Discharge

SLIDE 12

Climate Change

Issue on Bias correction of Snowfall in Large scale

# 12

Long-term Snowfall data ??? Past GCM Precipitation

Bias Correction Estimate Function

Future GCM Precipitation Access Impacts on Water resources, Food, Energy via various Modelling tools Reanalysis Data

Coarse
Bias

Distributed Snow and Glaciermelt Model Obs vs Sim Snow cover and Runoff Correct Reanalysis Data

SLIDE 13

Summary & Outlook

# 13  A Comprehensive Modeling system has been established which can

simulate the Snow processes and Glacier processes and Forest snow processes simultaneously in a basin scale. The model has been well implemented in the Upper Indus Basin.

 Validation of the model in Upper Indus basin will be carried out

following long term simulation (30 yrs). Finally, impact of climate change will be assessed.

 Inter-linkage of variability in flow of upper Indus basin to the lower

region will be addressed. Impact on irrigation, energy and socio- economic parameters will be studied through regional cooperation among different institutions and agencies.

Snow and glaciermelt runoff modeling in Upper Indus Basin of Pakistan

Maheswor SHRESTHA *Researcher, Department of Civil Engineering, University of Tokyo, JAPAN

7th GEOSS Asia Pacific Symposium

GEOSS AWCI Parallel Session:

Inter-linkage case study in Pakistan

Indus Basin - Resources Nexus

Snow/Glacier

Indus Basin - Resources Nexus

Snow/Glacier : Upper Indus Climate Change: How the equilibrium of this nexus will be affected ? Rainfall : Middle-Lower Indus

Modeling system

Which model?

Physics Based Distributed Hydrological Model

Hydrological Model

Water and Energy budget based distributed hydrological model with improved snow and glacier schemes (WEB-DHM-S)

Upper Indus Basin (200700 km2)

Grid size: 1 km

Data Set

Gauge Data – WAPDA

APHRODITE gridded precipitation data (25 km) Global Land Data Assimilation System (GLDAS) data (25 km)

Glacier Cover data

Hunza Basin (13733 km2)

Hunza Basin

Snow/Glacier Cover Area

Snow/Glacier State simulation (2001-2002)

Hunza Basin

Daily Discharge

Snow & glacier melt contribution = 80-85 % (50-60% snowmelt) Rainfall contribution = 15-20% Calibration Validation

Upper Indus Basin (200700 km2)

Grid size: 1 km

 Simulation results follows the seasonal variation of snow cover represented by the MODIS  However, large discrepancies were observed while performing pixel-pixel analysis, mainly due to the uncertainty in spatial distribution of APHRODITE precipitation. Snow Cover Area

Indus Basin (200700 km2)

Daily Discharge

Long-term simulation 1980-2012 is

Daily Discharge

Climate Change

Issue on Bias correction of Snowfall in Large scale

Long-term Snowfall data ??? Past GCM Precipitation

Future GCM Precipitation Access Impacts on Water resources, Food, Energy via various Modelling tools Reanalysis Data

Distributed Snow and Glaciermelt Model Obs vs Sim Snow cover and Runoff Correct Reanalysis Data

Summary & Outlook

simulate the Snow processes and Glacier processes and Forest snow processes simultaneously in a basin scale. The model has been well implemented in the Upper Indus Basin.

following long term simulation (30 yrs). Finally, impact of climate change will be assessed.

region will be addressed. Impact on irrigation, energy and socio- economic parameters will be studied through regional cooperation among different institutions and agencies.

Thank you !!