Draft Prepared for: RIZA Arnhem FEWS-Rhine version 1.02 Improvements and adjustments Report November 2004 Q3618.00 Prepared for: RIZA Arnhem FEWS-Rhine version 1.02 Improvements and adjustments Albrecht Weerts & Hanneke Van de Klis Report November, 2004 FEWS-Rhine version 1.02 Q3618.00 November 2004 Improvements and adjustments Contents 1 Introduction.........................................................................................................1—1 2 State Management SOBEK................................................................................2—1 2.1 Introduction..............................................................................................2—1 2.2 State handling FEWS general ..................................................................2—1 2.3 SOBEK ....................................................................................................2—2 3 Implementation of a new SOBEK model..........................................................3—1 3.1 Introduction..............................................................................................3—1 3.2 Important file ...........................................................................................3—1 3.3 Implementation new SOBEK model .......................................................3—2 3.4 Implementation new SOBEK executable ................................................3—2 3.5 Implementation adapted SOBEK model..................................................3—2 3.6 Implementation of an extra SOBEK model.............................................3—3 3.7 Addition EKF module to SOBEK model ................................................3—4 3.8 Implementation adapted model with EKF ...............................................3—4 3.9 Implementation new SOBEK model with EKF.......................................3—4 3.10 References................................................................................................3—4 4 Implementation of Extended Kalman Filter in FEWS Rhine.........................4—1 4.1 Introduction..............................................................................................4—1 4.1.1 Background.................................................................................4—1 4.1.2 Problem definition ......................................................................4—1 4.1.3 Approach ....................................................................................4—1 4.1.4 Outline of the report....................................................................4—1 4.2 Model description ....................................................................................4—2 WL | Delft Hydraulics i FEWS-Rhine version 1.02 Q3618.00 November 2004 Improvements and adjustments 4.2.1 FEWS/SOBEK ...........................................................................4—2 4.2.2 Sample data for assimilation.......................................................4—2 4.2.3 Data for calibration.....................................................................4—3 4.2.4 Software version used.................................................................4—3 4.3 Calibration ...............................................................................................4—3 4.3.1 Introduction.................................................................................4—3 4.3.2 Calibration of EKF .....................................................................4—4 4.3.3 Effect of EKF on forecast ...........................................................4—5 4.4 EKF in FEWS........................................................................................4—10 4.5 Discussion, conclusions and recommendations.....................................4—10 4.5.1 Conclusions ..............................................................................4—10 4.5.2 Recommendations.....................................................................4—10 4.6 References..............................................................................................4—11 5 AR Error Module for FEWS-Rhine..................................................................5—1 5.1 Role in FEWS..........................................................................................5—1 5.2 Functionality described............................................................................5—1 5.3 Data Requirements...................................................................................5—2 5.3.1 Input time series data..................................................................5—2 5.3.2 Output time series data ...............................................................5—2 5.3.3 Configuration data ......................................................................5—3 5.3.4 Current configuration..................................................................5—3 Conditions and Assumptions ...................................................................5—6 5.3.5 Time series definitions................................................................5—6 5.3.6 AR estimation .............................................................................5—6 5.3.7 Box-Cox transformations............................................................5—6 5.3.8 Application of the Module..........................................................5—7 WL | Delft Hydraulics ii FEWS-Rhine version 1.02 Q3618.00 November 2004 Improvements and adjustments 5.4 References..............................................................................................5—10 6 Other adjustments ..............................................................................................6—1 6.1 Multiple numerical weather prediction (NWP) .......................................6—1 6.2 Adjusted interpolation rainfall forecast ...................................................6—2 6.3 Adjusted interpolation rainfall update .....................................................6—2 7 Conclusion and Discussion.................................................................................7—1 Appendices: A Listings of .csv files ...........................................................................................A–1 B Input file Extended Kalman Filter .....................................................................B–1 WL | Delft Hydraulics iii FEWS-Rhine version 1.02 Q3618.00 November 2004 Improvements and adjustments 1 Introduction Through RI-3987, RIZA Arnhem requested WL | Delft Hydraulics to improve and adjust FEWS-Rhine. FEWS-Rhine is a flood forecasting system and must be able to extend the lead time for prediction of the water level at Lobith from 2 to 4 days with a certain accuracy. December 2002, a prototype was developed and finished together with the BfG, BWG, SMHI and WL | Delft Hydraulics. The idea is to perform daily calculations with this prototype. However, some issues need to be solved before this daily routine will be possible. Therefore the nine 9 points below needed to be dealt with 1) State management SOBEK model (see chapter 2) 2) SOBEK manual (see chapter 3) 3) Enable multiple forecasts (see chapter 6.1) 4) Implementation of Kalman Filtering (see chapter 4) 5) Implementation of Error Correction (see chapter 5) 6) Solve database problem (solved) 7) Adjust quantitative precipitation forecast interpolation (see chapter 6.2) 8) Adjust interpolation precipitation update interpolation (see chapter 6.3) 9) Provide a FEWS-Rhine Course for RIZA employees (held December 9 2003) Seven of the nine points are described in following chapters. The database problem has been solved and the FEWS-Rhine course has been held Friday December 12 2003 at RIZA Arnhem. We will conclude with a short discussion of issues that may need future attention. This document has been written by WL | Delft Hydraulics for the client RIZA Arnhem, within the framework of the project ‘Uitvoeren van aanpassingen en verbeteringen in FEWS Rijn’ (Q3618). The contact of RIZA Arnhem is Eric Sprokkereef. The project leader at WL | Delft Hydraulics is Albrecht Weerts. Hanneke van de Klis, Onno van de Akker, Erik de Rooij, Paolo Reggiani and Albrecht Weerts are project team members. Micha Werner is reviewer of the project. WL | Delft Hydraulics 1—1 FEWS-Rhine version 1.02 Q3618.00 November 2004 Improvements and adjustments 2 State Management SOBEK 2.1 Introduction In version 1.0 of FEWS Rhine the SOBEK models have default initial states. However, SOBEK is able to produce restart files which can be used as initial condition for a following run. This option needs to be enabled in the improved version of FEWS-Rhine. 2.2 State handling FEWS general The implementation is according to the implementation of the state management of the HBV model. Figures 2.1, 2.2 and 2.3 show how it has been implemented. Cold Start HBV Groundwater SOBEK T0-Tcs T0-30 T0-8 T0 T0+4 time Figure 2.1 Cold Start FEWS-Rhine. Warm Start HBV Groundwater SOBEK T0-30 T0 T0+4 time T0-Tws Figure 2.2 Warm start FEWS-Rhine WL | Delft Hydraulics 2—1 FEWS-Rhine version 1.02 Q3618.00 November 2004 Improvements and adjustments Procedure Warm starts Cold start time T1-30 T1 T2 T3 T4 T5 T6 T7 T8 T9 Figure 2.3 Procedure First, a cold start will be necessary (Figure 2.1). This will be followed by a warm start (Figure 2.2), however this is only possible (Figure 2.3) if the initial states for a warm start are available. This means that a number of cold runs are necessary before one switches to a warm start. 2.3 SOBEK After a SOBEK run two files are produced sobekrst.nda