1. Streamflow Data Assimilation Christoph Rüdiger Supervisors: Jeffrey Walker, University of Melbourne, Australia Jetse Kalma, University of Newcastle, Australia Garry Willgoose, University of Leeds, United Kingdom

2. Christoph Rüdiger Dept. Seminar 1 May 2003 Overview Research objectives Introduction to field sites and instrumentation Approach to the problem and future tasks –Hydrological model –Data assimilation Problems in general

3. Christoph Rüdiger Dept. Seminar 1 May 2003 Research Objectives Streamflow data assimilation for use of soil moisture predictions in a hydrological model Joint assimilation of streamflow data and near surface soil moisture into a hydrological model

4. Christoph Rüdiger Dept. Seminar 1 May 2003

5. Soil Moisture? What for? Drought monitoring Flood prediction Irrigation policies Weather forecasting

6. Christoph Rüdiger Dept. Seminar 1 May 2003 Field Site (SASMAS) Goulburn River Catchment –Proximity to Newcastle –Size and geophysical properties –Cleared areas –Division into 4 subcatchments

7. Christoph Rüdiger Dept. Seminar 1 May 2003 Vegetation and Soils (SASMAS) 50km 40km

8. Christoph Rüdiger Dept. Seminar 1 May 2003 Location of Instrumentation Soil Moisture Sites DLWC Stream Gauges Weather Stations Project Stream Gauges Subcatchments Microcatchment

9. Christoph Rüdiger Dept. Seminar 1 May 2003 Surface Conditions (MARVEX) (from Woods et al., 2001)

10. Christoph Rüdiger Dept. Seminar 1 May 2003 Site Locations Stream gauges Raingauges Soil moisture sites (from Woods et al., 2001)

11. Christoph Rüdiger Dept. Seminar 1 May 2003 Approach Hydrological modelling (VIC-3L model; Liang et al. 2001) with synthetic and real data Data assimilation Routing model Test on different climates and scales (Goulburn and Mahurangi catchments – subcatchments only and full sized) Joint streamflow & near-surface soil moisture data assimilation

12. Christoph Rüdiger Dept. Seminar 1 May 2003 Variable Infiltration Capacity bucket theory Xinanjiang distribution (from Wooldridge et al., 2001)

13. Christoph Rüdiger Dept. Seminar 1 May 2003 What is Sequential Data Assimilation? model output error

14. Christoph Rüdiger Dept. Seminar 1 May 2003 What is Variational Data Assimilation? model output

15. Christoph Rüdiger Dept. Seminar 1 May 2003 Problems in General Model assumptions (hydrological models & routing model) Accuracy of instrument data (sensors & stream gauges) Corruption of satellite data Accessibility and representativeness of soil moisture sites (Grayson and Western, 1998)