Transcript Climate Change and Variability over India : Observations

Impacts of Climate Change on
Water Resources
INDIAN INSTITUTE OF TROPICAL METEOROLOGY
G.B. Pant
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
The People
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Dr. G.B. Pant (PI)
Dr. K. Rupa Kumar
Mr. B.N. Mandal
Dr. K. Krishna Kumar
Dr. B.D. Kulkarni
Mrs. N.R. Deshpande
Collaborators/Consultants:
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Dr. K.S. Ramasastri, National Institute of
Hydrology
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
OUTLINE
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Objectives
Research Tasks
Indian rainfall variability
Baseline precipitation analysis
Precipitation climatology of major river basins
Spatio-temporal variability of precipitation
over major river basins
Evaluation of HadRM2 simulations of
precipitation over major river basins
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Objectives
Analysis of spatio-temporal variability of precipitation
over major river basins of India
 Study of past changes in water availability and their
sensitivity to climate variability and land-use/landcover changes
 Evaluation of regional climate model simulations of
precipitation
 Study of past changes in water quality
 Development of future scenarios for water availability
and quality under different climate change scenarios
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Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Research Tasks
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Identification of target river basins
Baseline precipitation analysis: Precipitation climatology of
major river basins; Spatio-temporal variability of precipitation
Evaluation of HadRM2 simulations of monthly/daily precipitation
over major river basins
Case studies of past changes in water availability and quality in
relation to climate and land-use/land-cover changes
Hydrometeorological analysis of HadRM2 simulations for major
river basins
Water availability scenarios for major river basins including the
scenarios for the impacts of land use and cover
Identification of critical areas and frequency/impacts of extreme
events
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Mean Rainfall Patterns
Data Source: CMAP (1979-2000)
Summer Monsoon
(mm/season)
Annual
(mm/year)
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Indian Summer Monsoon
Contribution to Annual Rainfall and its Variability
Data Source : CMAP (1979-2000)
Monsoon/Annual (%)
Coefficient of Variation (%)
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
The Stability of the Indian Summer Monsoon
120
Mean (R) = 84.8 cm
Standard Deviation (S) = 8 cm
100
R+S
R
Rainfall (cm)
80
R-S
60
40
20
0
1810
1830
1850
1870
1890
1910
1930
1950
1970
Years
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
1990
Temporal scales of monsoon
variability
Factors
Features
Intraseasonal
Interannual
Decadal/Century
Millennia &
longer
Onset/withdrawal;
Active and breakmonsoon phases;
30-50 day
oscillations;
severe rainstorms
Droughts and
floods
Changes in the
frequency of
droughts and floods
Changes in the
areal extents of
monsoons
Atmospheric
variability;
tropicalmidlatitude
interactions;
Soil moisture;
Sea surface
temperatures
Atmospheric
interactions;
El Niño/
Southern
Oscillation;
Top layers of
tropical oceans;
Snow cover;
Land surface
characteristics
Monsoon circulation
variations;
Deep ocean
involvement;
Greenhouse gases
increase;
Human activities;
Biospheric changes;
Volcanic dust
Global climate
excursions;
Ice ages;
Warm epochs;
Sun-earth
geometry
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Rainfall Data
Homogeneous monthly rainfall data set
for 306 stations (1871-2001)
 Daily rainfall data at 500-1000
raingauge stations during 1901-90
(variable network)
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Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Change in Raingauge Network Density
(1871-1992)
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Raingauge Network for Daily Rainfall Data
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
All-India Summer Monsoon Rainfall (1871-2001)
(Based on IITM Homogeneous Monthly Rainfall Data Set)
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Long-term Trends in
Indian Summer
Monsoon Rainfall
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Major River Basins of India
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Identification of
Target River Basins
66 notable river basins
 3 large river basins identified : Ganga,
Godavari and Krishna
 Summer monsoon main source of water
for all the three basins
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Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Seasona Precipitation : GANGA
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Seasonal Precipitation : GODAVARI
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Seasonal Precipitation : KRISHNA
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Variation of Basin-mean Precipitation:
GANGA
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Variation of Basin-mean Precipitation:
GODAVARI
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Variation of Basin-mean Precipitation:
KRISHNA
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Extreme Rainfall in River Basins
Short-duration extremes in rainfall have
profound influence on the water
availability as well as flood-related
issues
 1-3 day extreme rainfall patterns have
been analysed to study this aspect
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Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Extreme Rainfall : GANGA
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Extreme Rainfall : GODAVARI
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Extreme Rainfall : KRISHNA
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
All-India Mean Monthly Rainfall
10
Observed
CTL
GHG (2041-60)
9
8
Rainfall (mm/day)
7
6
5
4
3
2
1
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Months
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
All-India Seasonal Rainfall
900
800
Observed
CTL
GHG (2041-60)
Rainfall (mm/season)
700
600
500
400
300
200
100
0
DJF
MAM
JJAS
ON
Season
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Annual Cycles of
Rainfall in Major River
Basins of India
Godavari
50
Observed
Control
GHG
Rainfall (cm/month)
40
Ganga
30
20
10
50
0
Observed
Control
GHG
Jan
Feb
Mar
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Krishna
30
50
Observed
Control
GHG
20
40
10
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Rainfall (cm/month)
Rainfall (cm/month)
40
Apr
30
20
10
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002
Sep
Oct
Nov
Dec
Capital Equipment
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A high-end workstation along with PCs
and on-line UPS have been acquired for
the project
Indo-UK Programme on Climate Change Impacts in India : Delhi Workshop, Sep. 5-6, 2002