Mitigation of growing stress on water resources in Brasília/DF - Development of Regional Climate Change Scenarios using Statistical Downscaling

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1 Desenvolvimento de um Sistema de Gestão Integrada Mitigation of growing stress on water resources in Brasília/DF - Development of Regional Climate Change Scenarios using Statistical Downscaling Pablo Borges de Amorim Prof. Dr. Christian Bernhofer Chair of Meteorology TUD CCRR-2013 Dresden Mai 27th, 2013 Supported by: 1

2 Desenvolvimento Development of Regional de um Sistema Climate Change de Gestão Scenarios Integrada Drivers Climate TUD-M/INMET Population growth UFZ/UnB-G Land use TUD-B/UnB-G/EMBRAPA Policies/Economy CAESB IWAS/Brazil Concept Driver State Pressure Impact Reaction Capacity Development Sachsen Wasser Waste Water CAESB/UBW/KIT/TUD-S Catchments CAESB/UFZ/UnB-E/TUD-B Water quality CAESB/KIT/UBW/TUD-W Water Balance CAESB/UFZ/TUD-B Sediments CAESB/KIT/UFZ/UnB/TUD-B Drinking Water CAESB/TUD-S Water Supply Security Evaluation & Recommendation CAESB/TUD/UFZ/UnB Lorz et al. 2012

3 Desenvolvimento Development of Regional de um Sistema Climate Change de Gestão Scenarios Integrada Climate Current Climate Assess the regional climate patterns Climatology Spatial Distribution Trend Analysis Future Climate Develop regional climate change scenarios GCMs analysis Downscaling Borges et al. 2013a Borges et al. 2013b

4 Statistical Downscaling Desenvolvimento Development of Regional de um Sistema Climate Change de Gestão Scenarios Integrada SDSM Tool; Empirical relationship between Predictors and Predictand; Transfer function: Hybrid of multiple linear regression + stochastic downscaling methods (Wilby and Dawson, 2007) 1. Screening Variables 2. Calibrate the Model 3. Weather Generator 4. Scenarios Generator Predictor Predictand H( ) V( ) U( ) Z( ) T( ) Transfer Function Temp Prec Figure: Need for developing regional climate scenarios. Source: Maurer, 2001

5 Desenvolvimento Development of Regional de um Sistema Climate Change de Gestão Scenarios Integrada Screenig Variables Predictor Predictand Relationship; In principle, predictors should be physically related to predictand; Condition: regression coefficients, explained variance, standard error. Table: List of the best predictors to be used for statistical downscaling for the station of Brasília - INMET. predictor Tmean Prec p_5u X X p500 p850 X X r500 X X r850 rhum temp X X X where p u = Surface zonal velocity p = geopotential height r = Relative humidity temp = Mean temperature at 2m

6 Desenvolvimento Development of Regional de um Sistema Climate Change de Gestão Scenarios Integrada Screenig Variables Calibration NCEP/NCAR Reanalysis 1; Procedure: calibration ( ) validation ( ) Multiple linear regression equations. Table: Downscaling Skill (standard error and explained variance) Tmean Calibration Prec SE r^2 SE r^2 jan feb mar apr may jun jul aug sep oct nov dec Validation

7 Desenvolvimento Development of Regional de um Sistema Climate Change de Gestão Scenarios Integrada Screenig Variables Calibration Weather Generator Synthetic time series OBS daily p_5u daily p500 daily r850 daily MLR equations monthly - MLR Time series daily Residuals daily Variance Inflation monthly Random number (Monte Carlo) p_5u daily p500 daily r850 daily MLR eq + monthly MLR ts daily Increment daily = Synthetic time series

8 Screenig Variables Calibration Weather Generator Validation Mean Temperature ( ) Desenvolvimento Development of Regional de um Sistema Climate Change de Gestão Scenarios Integrada Corre.Coef MSE MSE

9 Screenig Variables Calibration Weather Generator Validation Precipitation ( ) Desenvolvimento Development of Regional de um Sistema Climate Change de Gestão Scenarios Integrada correl.coef MSE

10 Screenig Variables Calibration Weather Generator Scenarios Generator Mean Temperature ( ) Desenvolvimento Development of Regional de um Sistema Climate Change de Gestão Scenarios Integrada Assumption: Predictor/Predictand Relationship will remain.

11 Screenig Variables Calibration Weather Generator Scenarios Generator Desenvolvimento Development of Regional de um Sistema Climate Change de Gestão Scenarios Integrada Assumption: Predictor/Predictand Relationship will remain. Precipitation ( )

12 Desenvolvimento Development of Regional de um Sistema Climate Change de Gestão Scenarios Integrada Conclusions SDSM Tool: Relative easy User Interface Platform; Computationally efficient; Based on standard and accepted statistical procedures. Require long and reliable observed historical data; Stationarity in the predictor/predictand relationship. Temperature: Annual cycle; annual and monthly means; variance; and extreme values; Good downscaling skill; Underestimates in winter. Precipitation: Annual cycle; annual and monthly totals; and rainfall occurrence; Good downscaling skill for rainfall occurrence; Underestimate the rainfall variance at the end of the rainy season; daily rainfall intensity not well represented; and underestimate extreme events. Analysis on frequency of extreme events is needed; Include other climatic variables (humidity, wind velocity and global radiation); MPI for GCMs and new generation (CMIP5).

13 Desenvolvimento Development of Regional de um Sistema Climate Change de Gestão Scenarios Integrada Literature Borges PA, Franke J, Silva FDS, Weiss H, Bernhofer C (2013a) Differences between two climatological periods ( vs ) and trend analysis of temperature and precipitation in Central Brazil. Theor. and Appl. Climatol., Manuscript accepted. Borges PA, Barfus K, Weiss H, Bernhofer C (2013b) Consistent analysis of GCMs simulations (CMIP3) of annual mean surface air temperature and precipitation changes ( vs ) in Distrito Federal, Brazil. Environ. Earth Sci. Manuscript submitted for publication. Lorz C, Abbt-Braun G, Bakker F, Borges P, Börnick H, Fortes L, Frimmel F, Gaffron A, Hebben N, Höfer R, Makeschin F, Neder K, Roig HL, Steiniger B, Strauch M, Walde DH, Weiß H, Worch E, Wummel J (2012) Challenges of an integrated water resource management for the Distrito Federal, Western Central Brazil: climate, land-use and water resources. Environ. Earth. Sci. 65(5): doi: /s Maurer Ed (2009) Translating Global Models to the Local Scale. Presentation. OCCRI Workshop, October Santa Clara University. Wilby RL, Dawson CW (2007) SDSM 4.2 A decision support tool for the assessment of regional climate change impacts. User Manual. Lancaster University, UK.

14 Desenvolvimento de um Sistema de Gestão Integrada Mitigation of growing stress on water resources in Brasília/DF - Development of Regional Climate Change Scenarios using Statistical Downscaling pablo.amorim@mailbox.tu-dresden.de pablo.borges@ufz.de Pablo Borges de Amorim Prof. Dr. Christian Bernhofer Chair of Meteorology TUD CCRR-2013 Dresden Mai 27th, 2013 Supported by: 14