WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
WFM 6311: Climate Change Risk
Management
Lecture-9: Handson Exercise using
SDSM to downscaling Temperature of a
selected station of Bangladesh
Akm Saiful Islam
Institute of Water and Flood Management (IWFM)
Bangladesh University of Engineering and Technology (BUET)
March, 2013
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Lecture Topic
Download and Installation of SDSM
 Download of GCM data
 Preparation of Station data
 Consistency of station data
 Calibration and validation of model
 Future scenario generations

WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Getting Started
http://co-public.lboro.ac.uk/cocwd/SDSM/
First
Register yourself
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Installing the software
https://co-public.lboro.ac.uk/cocwd/SDSM/software.html
Statistical Downscaling Input
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
http://cccsn.ca/?page=sdsm
Statistical Downscaling Input
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
(25x 25y)
(90, 25)
(90, 22.5
(25x 26y)
Dhaka BMD station
(90.38 , 23.78)
Box # ??
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Statistical Downscaling Input

H3A2a_1961-2099 (Hadley Centre Climate Model 3 Emissions Scenario A2 pessimistic)

h3a2mslpas.dat
 h3a2p5_fas.dat

H3B2a_1961-2099 (B2 - optimistic)

h3b2mslpas.dat
 h3b2p5_fas.dat etc

NCEP_1961-2001

ncepmslpas.dat
 ncepp5_uas.dat etc (26 files)
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Statistical Downscaling Input
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
[source] [variable]
[grid box] . Dat
nceprhumee.dat ??????
h3b2p8_zsw.dat ??????
h2ggp_thas.dat ??????
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Station Data Preparation
(1961 -2000)
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Select Settings
Check Calendar (366)
Uncheck ‘Allow -ve values’
Event threshold = 0(temp)
= 1 (rainfall)
Data 1/1/1961 – 12/31/2000
 Save the settingc
For Easy selection
Select the source directory of your station data
Select the folder that has your predictand /data
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Click on advance of settings
Option ‘None’ for temperature
Others for rainfall (i.e., fourth root)
Save the settings
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Click Quality Control
Then Select file
Open the input station data
Click on the Check file
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
 If OK appears, quality check is complete.
Manually use the judgment by checking the maximum difference of the temperature
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Data Transformation
Change of predictors (optional)
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Screen Variables
ATTENTION
Select the NCEP_1961-2000
folder of appropriate Box
ATTENTION
Temp
Unconditional
Rainfall
Conditional
 Select station data as the predictand file (i.e Tmax_dat)
Select your data period (61-00) and analysis period (i.e. Annual)
Check your process condition (i.e. conditional)
Amend the significance level (i.e. 0.05 for 5% significant value).
SELECT APPROPIATE COMBINATION OF PREDICTOR VARIABLES (<#12)
PRESS
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
 Choose those combination of variables where
partial correlation (r) is high but with P value ≈ 0
Go back and PRESS
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Example: Dhaka Station
Analysis Results
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Example: Dhaka Station
Scatter Plot
Station data Vs 1 Predictor
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Dhaka Station (CALIBRATE MODEL)
Select
those
chosen
combination
1961-1980 for
Tmax_61-80.PAR
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Dhaka Station (Calibration Results)
Standard Error = 2%
(Average)
Explained Variance = 23.65%
(Average)
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Weather Generator
(to Validate create output file from 1981-2000)
NCEP Files
1/1/1981 for
Tmax_NCEP_81-00
From
Tmax_61-80.PAR
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Summary Statistics
Go to Summary statistics and press
Select suitable statistics (maximum up to 8), and go back
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Summary Statistics
Click
1981-2000
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Compare Results
Check the results (i.e. mean Vs
mean)
If unsatisfactory, choose another
combination of screen variables and
repeat the above procedures.
Validation is an iterative process
If satisfactory, Go to
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Create calibrated file
Create Tmax_61-00.PAR with same screen variables combination (validated)
Use the data period 1961 – 2000
 Calculate the Explained Variance
Explained
Variance = 26.04%
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Create Present Climatic data (NCEP_1961-1990)
Tmax_61-00.PAR
NCEP Files
Tmax_NCEP_1961-2000.out
1/1/1961
Calibrate Model
61-00.PAR->
NCEP_61-00.OUT
Summary Statistics
NCEP_61-00.OUT->NCEP61-00.TXT
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Creating Model Data
Tmax_61-00.PAR
H3A2_1961-2000
Change the settings calendar to 360 (GCM)
Create H3 A2 or H3 B2 model data (.out) through Scenario Generation
for the year 1961-2000
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Creating Model data (present
+Future)
Choose Modelled
INPUT FILE
Tmax_H3A2_1961-2000.out
Analysis period will depend
on the desired (present or
future) data time
‘Summary statistics’
Choose Statistics options
Create text files (Tmax_H3A2_1961-2000.txt, Tmax_H3A2_2011-2040.txt etc.)
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Sample: Delta Stats Results
Choose Modelled
INPUT FILE
H3A2_1961-2000.out
Analysis period 1961-2099
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Sample: Delta Stats Results……… Cont
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Sample: Generated output data
WFM 6311: Climate Risk Management © Dr. Akm Saiful Islam
Sample: Frequency Analysis
Tmax.dat as the observed data
H3A2_1961-2000.out as the modelled data
Ensemble Mean (Q-Q plot)
Ensemble Member 1 (FA)