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WFM 6311: Climate Change Risk Management

Akm Saiful Islam. WFM 6311: Climate Change Risk Management. Lecture-9: Handson Exercise using SDSM to downscaling Temperature of a selected station of Bangladesh. Institute of Water and Flood Management (IWFM) Bangladesh University of Engineering and Technology (BUET). March, 2013.

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WFM 6311: Climate Change Risk Management

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  1. Akm Saiful Islam WFM 6311: Climate Change Risk Management Lecture-9: Handson Exercise using SDSM to downscaling Temperature of a selected station of Bangladesh Institute of Water and Flood Management (IWFM) Bangladesh University of Engineering and Technology (BUET) March, 2013

  2. 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

  3. Getting Started First Register yourself http://co-public.lboro.ac.uk/cocwd/SDSM/

  4. Installing the software • After login click on the ‘software’ of the menu bar or go to https://co-public.lboro.ac.uk/cocwd/SDSM/software.html • Download SDSM 4.2.9 and the manual

  5. Statistical Downscaling Input • Go to http://cccsn.ca/?page=sdsm • Click on the ‘Statistical Downscaling Input’ on the left panel. • Then click on HadCM3 Predictors

  6. Statistical Downscaling Input Which box to choose?

  7. (90, 25) (90, 22.5) (25x 26y) Dhaka BMD station (90.38 , 23.78) Box # ?? (25x 25y)

  8. 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)

  9. Statistical Downscaling Input • Depending on the location of the station data, choose the right box numbers and click on the ‘Get data’. For example, for Dhaka station choose 25X25Y. • Downloading of the zip file will start.

  10. [source] [variable] [grid box] . Datnceprhumee.dat ??????h3b2p8_zsw.dat ??????h2ggp_thas.dat ??????

  11. Station Data Preparation(1961 -2000)

  12. 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

  13. Click on advance of settings • Option ‘None’ for temperature • Others for rainfall (i.e., fourth root) • Save the settings

  14. Click Quality Control • Then Select file • Open the input station data • Click on the Check file

  15. If OK appears, quality check is complete. • Manually use the judgment by checking the maximum difference of the temperature

  16. Data TransformationChange of predictors (optional)

  17. Screen Variables ATTENTION Select the NCEP_1961-2000 folderof appropriate Box ATTENTION Temp Unconditional Rainfall Conditional • Select station data as the predictand file (i.eTmax_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

  18. Choose those combination of variables where partial correlation (r) is high but with P value ≈ 0 • Go back and PRESS

  19. Example: Dhaka Station Analysis Results

  20. Example: Dhaka Station Scatter Plot Station data Vs 1 Predictor

  21. Dhaka Station (CALIBRATE MODEL) Select those chosen combination 1961-1980 for Tmax_61-80.PAR

  22. Dhaka Station (Calibration Results) Standard Error = 2% (Average) Explained Variance = 23.65% (Average)

  23. 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

  24. Summary Statistics • Go to Summary statistics and press • Select suitable statistics (maximum up to 8), and go back

  25. Summary Statistics Click 1981-2000

  26. 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

  27. 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%

  28. 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

  29. 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

  30. 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.)

  31. Sample: Delta Stats Results Choose Modelled INPUT FILE H3A2_1961-2000.out Analysis period 1961-2099

  32. Sample: Delta Stats Results……… Cont

  33. Sample: Generated output data

  34. 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)

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