Murrumbidgee Basin OzNet Station Update

Rodger Young - Field Research EngineerRodger Young - Field Research Engineer

Responsible for :Responsible for : - site installation - site installation

- data acquisition- data acquisition

- site maintenance- site maintenance

- laboratory studies- laboratory studies

3RD NAFE Workshop – University of Melbourne, Sept 2007

OzNet Station Location

MurrumbidgeeCatchment

Murray-DarlingBasin

Melbourne

MurrumbidgeeCatchment Topography

( 13 sites)

Cooma Aerodrome

Adelong Creek

Kyeamba Creek

Yanco Site

Griffith Aerodrome

Balranald Site

Original ‘Old’ CS615 Monitoring Stations

The original 18 - CS615 field monitoring stations were installed in spring 2001. The sites were chosen to cover the whole catchment with intensive study groupings of 5 sites in each of the Adelong and Kyeamba Creek sub-catchments.

Later ‘New’ CS616 Monitoring Stations

An additional 20 - CS616 field monitoring stations were installed in spring 2004 with a view to recording satellite ground truthing data.The two grouped locations chosen were:

• within the Kyeamba Creek sub-catchment• and in the Yanco district.

Three Instrumented Areas

Yanco area(2500 km2)

KyeambaCreekcatchment(600 km2)

AdelongCreekcatchment(100 km2)

Murrumbidgee RiverCatchment(1000002 km)

Kyeamba Creek ‘New’ CS616 Sites

K6

K10

K8

K14

Yanco District ‘New’ CS616 Sites

Y9

Y2 Y4

Y11

Sites approximating tothis grid arrangement

60km

60k

m

Measurement Validation for Old CS615 Monitoring Stations

CS615 Measurement Validation- TDR sensors were installed as an aid to CS615 calibration- Soil temperature sensors were installed as the CS615 signal is temp dependent- Gravimetric sampling was attempted at each depth

CS615 General Soil Moisture Calibration Relationship

0.4 N

N = (P25 – P0.0) / (P0.4 - P0.0)

Western and Seyfried

Where the temperature corrected (to 25oC) period measurement of the sensor is obtained from :

P25 = [Pobs – o(T – 25)] / [ 1 + s(T – 25)]

Where s is the slope and o is the offset of the temperature correction function for each site :

CT = sP25 + o

CS615 General Soil Moisture

0.0

10.0

20.0

30.0

40.0

50.0

60.0

0.000 0.200 0.400 0.600 0.800 1.000 1.200 1.400 1.600

Normalised Period

Mea

sure

d V

olu

met

ric

So

il M

ois

ture

(%

)

Series1

Series2

The figure shows a plot of the optimal normalised period N against measured soil moisture from all sites. From the high R2 value of 0.95 and low RMS error of 2.5%v/v, the fit is acceptable.

Measurement Validation forNew CS616 Monitoring Stations

CS616 Measurement Validation- TDR was installed as an aid to CS615 calibration- Temperature sensor installed at 15cm only- Bulk sampling for Laboratory calibration study and soil particle analysis- Gravimetric sampling was attempted

CS616 General Soil Moisture Calibration RelationshipN for N <=

N –

Rudiger

Kyeamba Soil Yanco 1 Soil Yanco 2 Soil Goulburn Fine Soil *

0.720 0.490 0.380 0.277

0.763 1.353 1.670 1.453

0.342 0.334 0.411 0.407

RMS 3.5%v/v 2.6%v/v 6.7%v/v %v/v

Dr Chris Rudiger 2007*

Soil Specific Curve Kyeamba CreekThis figure shows the plot of the optimal normalised period N against measured TDR soil moisture from sites within the Kyeamba Creek catchment. From the low RMS error value, the fit is acceptable.

Kyeamba Sites Normalised

0

5

10

15

20

25

30

35

40

45

50

0.0 0.2 0.4 0.6 0.8 1.0N

TD

R M

ois

ture

Co

nte

nt

%v/

v

k6

k7

k8

k10

k11

k12

k13

k14

[q]

Rudiger

RMS 3.5%v/v

Three sites outside the main grouping (X) need further investigation.

Soil Specific Curves Yanco Type1 SoilsThis figure shows the plot of the optimal normalised period N against measured TDR soil moisture from type1 soil sites within the Yanco district. From the low RMS error value, the fit is acceptable.

Must be noted that points from seven sites fell outside the main grouping and need further investigation ( shown here as Xs ).

Yanco Type1 Soil Sites Normalised

0

10

20

30

40

50

60

70

80

0.0 0.2 0.4 0.6 0.8 1.0 1.2N

TD

R M

ois

ture

Co

nte

nt

%v/

v

y1

y2

y4

y5

y6

y7

y8

y9

y10

y11

y12

y13

[q]

Rudiger

Curve fitted to closely grouped soil points - Yanco Type1 (O) with RMS 2.6%v/v.The remaining soil points - Yanco Type2 (X)

Soil Specific Curves Yanco Type2 SoilsThis figure shows the plot of the optimal normalised period N against measured TDR soil moisture from type2 soil sites within the Yanco district.

Yanco Type2 Soil Sites Normalised

0

10

20

30

40

50

60

70

80

0.0 0.2 0.4 0.6 0.8 1.0 1.2N

TD

R M

ois

ture

Co

nte

nt

%v/

v

y1

y2

y4

y5

y6

y7

y8

y9

y10

y11

y12

y13

Rudiger

[q]

Curve fitted to Yanco Type2 soil points (O) gave RMS 6.7%v/v.

CS616 Calibration Issues• The extended drought period over the time of the

Murrumbidgee study has made it difficult to collect undisturbed gravimetric samples from the hard dry clay soils, especially for 60-90cm.

• Instead, bulk soil samples have been collected for laboratory calibration studies.

• Soil temperature was only measured at a mean depth for the 0-30cm sensors therefore estimates were made for the temperatures at the 30-60cm and 60-90cm sensors using a simple ratio from the nearest site where temperatures at all depths were recorded.

Plans for Improvements to CS616 Calibration Relationship

• Laboratory study of CS616 responses using bulk soil samples which have been collected from the sites for the corresponding 0-30cm, 30-60cm and 60-90cm sensor depths. Unfortunately a time consuming procedure.

• Have recently received back the results of soil particle analysis to allow accurate grouping into soil types.

• Soil salinity testing will be carried out to further study sensor response issues.

OzNet Data- Records from 38 Murrumbidgee sites

- Bureau of Meteorology Data

- Kyeamba Flux Station Data

Soil Moisture, Rainfall, Ground Water

BOM stations : Yanco, Narrandera, Wagga Waggaplus at all of the original 18 Old Sites

UoM Flux Station : K10

Example of Yanco Soil MoistureY1 Spring 2006

0

5

10

15

20

25

30

35

40

1-Sep-06 8-Sep-06 15-Sep-06 22-Sep-06 29-Sep-06 6-Oct-06 13-Oct-06 20-Oct-06 27-Oct-06 3-Nov-06 10-Nov-06 17-Nov-06 24-Nov-06

Date

So

il T

emp

( °

C )

So

il M

ois

ture

(%

v/v)

0

5

10

15

20

25

30

20m

in R

ain

fall

(m

m)

SOIL TEMP_15cm SM_0-5_%v/v SM_0-30_%v/v SM_30-60_%v/v SM_60-90_%v/v 20MIN RAINFALL

NAFE 06

Bureau of Meteorology Data

Forcing Data Available :

- Rainfall- Air Temperature- Specific Humidity- Wind Speed- Short Wave Radiation- Long Wave Radiation

Kyeamba Creek Flux Station

3D sonic anemometer & open path gas analyser for LE & H, 3m above ground: 10Hz measurements, 30min averages recorded

Barometric pressure sensor: 1 reading per hourAir temperature & relative humidity probe, 2m above ground: 30min averages recordedWind direction and speed: 30min averages recordedTipping rain gauge bucket: 30min totals recorded4-way radiometer, incoming & outgoing shortwave & longwave radiation: 30min averages recorded

Below the Ground

30cm

60cm

90cm

8cm

(Not to scale)

CS615 Soil Moisture Probes: Measuring every 30 mins

Soil heat flux plates: 30min averages recorded

5cm10cm2cm

20cm

50cm

100cm

Soil temperature probes: Measuring every 30 mins

Eddy Covariance Data Sample

Heat Fluxes - Kyeamba Creek

-1000

100200300400500600700800

340 341 342 343 344 345Julian Days

Wm

-2

Latent (LE)Sensible (H)

Murrumbidgee Basin OzNet Station Update

Rodger Young - Field Research EngineerRodger Young - Field Research Engineer

Responsible for :Responsible for : - site installation - site installation

- data acquisition- data acquisition

- site maintenance- site maintenance

- laboratory studies- laboratory studies

3RD NAFE Workshop – University of Melbourne, Sept 2007