1. Scaling and Assimilation of Soil Moisture and Streamflow (SASMAS): project overview and preliminary results G Willgoose (U. Leeds, UK), H Hemakumara (U. Newcastle, Australia) C Rudiger (U. Melbourne, Australia) B Jacobs, J Kalma (U. Newcastle, Australia) J Walker (U. Melbourne, Australia) G Hancock, P Saco (U. Newcastle, Australia) P Houser (NASA Goddard, Hydrology Section)

2.  Validation of the soil moisture products from Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) … 50km pixels.  Development of scaling relationships for soil moisture  Estimating the spatial distribution and averages of soil moisture in large catchments by assimilating near surface moisture measurements and streamflow measurements  Estimation of temporal variation of soil moisture  Assimilating streamflow measurements to estimate soil moisture (specifically for forested areas)  TODAY: Focussing on preliminary data from SASMAS1 field campaign in October, 2003. SASMAS Objectives

3. Merriwa SASMAS Location Rainfall: 500-1000 mm Pan Evaporation: 1800 P/E: 0.3-0.6 Daily Temp: 16-30 (summer) 3-17(winter)

4. Soils and Geology Basalt Sandstone Soils Clay Silts

5. Vegetation

6. 0 - 30cm30 – 60 cm60 - 90cm 30cm 60cm backfilled soil Logger Permanent Soil Moisture Site Basalt Sites Sandstone Sites 26 sites soil moisture (mostly 3 levels) soil temperature (6 cm vertically, 12-18cm)

7. Location of Instrumentation Weather Stations Soil Moisture Sites Stream Gauges

8. Typical Data from Permanent Sandstone Monitoring Site

9. SASMAS 01 Sampling 40 x 50km area North of Goulburn River within unforested region 4 teams over 3 days Sampled area about scale of AMSR pixel 225 soil moisture samples sites (4 gravimetric, 5 theta probe (TDR)), 194 veg samples

10. Gravimetric Soil Moisture (0-1cm) 0.018 g/g 0.301 g/g

11. Theta Probe Soil Moisture (0-6cm) 0.02 g/g 0.28 g/g

12. TDR-Gravimetric Comparison Gravimetric (0-1cm)Theta Probe (0-6 cm)

13. Vegetation Soil Moisture and Biomass Correlations (?) No Apparent Correlation Weak Positive Correlation

14. Results from Ground observations  Avg MC, v/v (0-6cm) = 0.141  Avg MC, v/v (0-1cm) = 0.109 AMSR-E moisture values (v/v) using old (invalid?) NASA algorithm  Nov 7 – 0.15  Nov 8 – 0.15  Nov 9 – 0.15 AMSR Validation: Preliminary Results Comparison good (subject to the revised NASA AMSR-E inversion algorithm). No vegetation moisture correction in ground observations.

15. Conclusions Several additional field campaigns planned in 2004. Probably less extensive vegetation sampling allowing a greater density of soil moisture measurements. SASMAS 01 has delivered an extensive distributed soil moisture, soil temperature and vegetation data set for semi-arid conditions for dry (extreme drought) springtime conditions. Future campaigns will concentrate on wetter conditions. Currently have 16 months of distributed continuous data soil moisture at 26 sites and 3 depths, and soil temperature, with nested catchments with runoff data. Data for scaling studies of soil moisture and assimilation of distributed soil moisture from river discharges. Website with data and publications: (www.civag.unimelb.edu.au/~jwalker/data/sasmas)www.civag.unimelb.edu.au/~jwalker/data/sasmas Funding: Australian Research Council, NASA.