SEA Working Paper 00/12

Explaining groundwater hydrographs: separating atypical rainfall events from time trends

Ruhi FerdowsianA, David J. PannellB , Clare McCarronA, Arjen RyderA and Lisa CrossingA

AAgriculture Western Australia, Albany WA 6330, Australia.
BFaculty of Agriculture, University of Western Australia, Perth, WA 6907, Australia.

Tables

Table 1. Results of OLS estimations

       

Rainfall (m/mm)

Month (m/month)

 

Bore no

Rainfall variable

Lag (L) (months)

Constant

(K0) (m)**

Parameter estimate (K1)

P

Parameter estimate (K2)

P

R2

1

AMRR

28

-18.7

0.0024

0.000

0.018

0.000

0.93

2*

AMRR

28

-18.2

0.0007

0.000

0.018

0.000

0.99

3*

AMRR

10

-18.3

0.0004

0.042

0.012

0.000

0.95

4

AARR

7

-17.1

0.0013

0.181

0.017

0.000

0.63

5

AMRR

46

-15.6

0.0033

0.007

0.028

0.000

0.87

6

AMRR

14

-13.8

0.0016

0.000

0.025

0.000

0.91

7

AMRR

17

-12.8

0.0022

0.000

0.022

0.000

0.97

8

AARR

1

-13.5

0.0016

0.000

0.013

0.000

0.90

9*

AMRR

27

-12.5

0.0005

0.000

0.011

0.000

0.97

10

AMRR

11

-11.4

0.0019

0.000

0.027

0.000

0.98

11

AMRR

7

-8.2

0.0040

0.000

0.007

0.000

0.79

12

AMRR

6

-7.8

0.0036

0.000

0.016

0.000

0.95

13

AMRR

1

-6.4

0.0033

0.008

0.015

0.000

0.73

14

AMRR

17

-5.9

0.0005

0.357

0.017

0.000

0.90

15

AMRR

3

-5.7

0.0031

0.000

0.001

0.248

0.91

16

AMRR

6

-4.9

0.0035

0.000

0.005

0.006

0.62

17

AMRR

3

-5.5

0.0034

0.000

0.023

0.000

0.91

18

AMRR

2

-5.2

0.0019

0.000

0.008

0.000

0.80

19

AMRR

4

-5.0

0.0007

0.033

0.015

0.000

0.92

20

AMRR

0

-3.2

0.0020

0.066

0.015

0.000

0.48

21*

AMRR

3

-4.1

0.0032

0.000

-0.005

0.001

0.72

22

AMRR

0

-3.5

0.0053

0.000

-0.007

0.000

0.80

23

AMRR

1

-3.5

0.0041

0.000

-0.014

0.000

0.86

24

AMRR

0

-3.3

0.0061

0.000

-0.001

0.683

0.84

25

AMRR

6

-2.8

0.0048

0.000

0.020

0.000

0.96

26

AMRR

0

-3.7

0.0060

0.000

-0.016

0.000

0.82

27

AMRR

5

-3.2

0.0008

0.000

0.002

0.000

0.54

28

AMRR

0

-2.8

0.0024

0.000

0.012

0.000

0.79

29

AMRR

1

-2.6

0.0014

0.001

0.005

0.000

0.54

30

AARR

0

-2.2

0.0015

0.096

0.011

0.000

0.45

31*

AMRR

3

-2.3

0.0036

0.000

-0.005

0.002

0.77

32

AMRR

1

-1.4

0.0015

0.014

0.007

0.001

0.36

33

AARR

0

-2.0

0.0010

0.098

0.001

0.390

0.09

34

AMRR

0

-1.9

0.0011

0.035

0.000

0.843

0.20

35

AMRR

0

-1.5

0.0021

0.030

0.000

0.844

0.17

36

AMRR

0

-0.5

0.0008

0.277

-0.001

0.525

0.11

37

AARR

0

-1.4

0.0006

0.015

0.003

0.000

0.46

38

AMRR

1

-1.0

0.0016

0.009

0.001

0.505

0.34

39

AMRR

1

-1.0

0.0028

0.000

0.003

0.024

0.78

40*

AARR

1

-1.1

0.0024

0.000

-0.003

0.002

0.71

41

AARR

0

-0.8

0.0024

0.011

-0.006

0.045

0.41

42

AMRR

0

-1.4

0.0020

0.000

0.003

0.089

0.40

43

AMRR

0

-0.2

0.0035

0.005

-0.012

0.010

0.61

44

AMRR

0

-0.4

0.0018

0.000

0.005

0.016

0.58

45

AARR

0

-1.2

0.0026

0.024

-0.003

0.542

0.36

46

AARR

0

-0.9

0.0016

0.170

-0.009

0.093

0.34

47

AMRR

0

-0.6

0.0005

0.272

-0.002

0.127

0.15

48

AARR

0

-0.2

0.0018

0.000

-0.004

0.006

0.55

49

AMRR

0

-0.3

0.0007

0.006

0.000

0.663

0.25

*, Bores in Tertiary sand plain;

**, constant is approximately equal to initial depth to groundwater.

 

 

Table 2. Diagnostic test results for OLS models

Bore no

Omitted variable test

Heteroskedasticity test

Durbin-Watson statistic

1

0.021

*

0.091

 

1.13

++

2

0.052

 

0.021

*

1.07

++

3

0.792

 

0.104

 

1.47

+

4

0.799

 

0.054

 

2.14

 

5

0.000

*

0.082

 

0.53

++

6

0.466

 

0.000

*

1.37

++

7

0.001

*

0.645

 

0.88

++

8

0.003

*

0.022

*

1.02

++

9

0.222

 

0.562

 

1.57

+

10

0.000

*

0.550

 

0.54

++

11

0.438

 

0.947

 

1.09

++

12

0.001

*

0.001

*

1.44

+

13

0.000

*

0.789

 

0.39

++

14

0.336

 

0.001

*

0.17

++

15

0.282

 

0.011

*

1.23

++

16

0.556

 

0.289

 

1.53

+

17

0.288

 

0.676

 

1.71

 

18

0.173

 

0.740

 

0.81

++

19

0.743

 

0.752

 

1.83

 

20

0.059

 

0.039

*

1.13

++

21

0.577

 

0.997

 

0.79

++

22

0.152

 

0.400

 

0.72

++

23

0.115

 

0.001

*

0.33

++

24

0.823

 

0.448

 

1.58

+

25

0.963

 

0.707

 

1.19

++

26

0.003

*

0.831

 

0.89

++

27

0.261

 

0.457

 

1.16

++

28

0.011

*

0.304

 

0.80

++

29

0.116

 

0.959

 

0.83

++

30

0.170

 

0.450

 

0.79

++

31

0.175

 

0.965

 

1.44

+

32

0.303

 

0.001

*

1.33

++

33

0.755

 

0.020

*

1.96

 

34

0.400

 

0.418

 

0.58

++

35

0.325

 

0.849

 

0.74

++

36

0.515

 

0.011

*

0.41

++

37

0.790

 

0.213

 

0.75

++

38

0.029

*

0.334

 

1.66

 

39

0.432

 

0.827

 

0.40

++

40

0.809

 

0.880

 

0.55

++

41

0.410

 

0.139

 

0.29

++

42

0.576

 

0.758

 

1.00

++

43

0.542

 

0.803

 

0.49

++

44

0.208

 

0.609

 

1.87

 

45

0.600

 

0.615

 

0.81

++

46

0.000

*

0.552

 

0.34

++

47

0.041

*

0.402

 

1.06

++

48

0.184

 

0.141

 

1.46

 

49

0.974

 

0.794

 

1.20

++

*, Below critical value of 0.05;

+, below upper critical value of 1.62 (i.e. rejection of H0 of no serial correlation is not clear);

++, below lower critical value of 1.44 (i.e. reject H0 of no serial correlation, with P = 0.05).

 

 

Table 3. Results of PRAIS estimations

   

Rainfall variable (m/mm)

Month (m/month)

     

Bore no

Constant

(K0) (m)

Parameter estimate (K1)

p

Parameter estimate (K2)

p

R2

Durbin-Watson statistic

1

-18.7

0.0026

0.000

0.052

0.000

0.99

1.63

 

2

-18.2

0.0007

0.000

0.053

0.000

1.00

1.67

 

3

-18.3

0.0004

0.051

0.036

0.000

0.99

1.52

+

4

-17.1

0.0007

0.374

0.049

0.000

0.97

1.79

 

5

-15.7

0.0033

0.003

0.082

0.000

0.99

1.15

++

6

-13.9

0.0017

0.000

0.078

0.000

1.00

1.29

++

7

-12.8

0.0021

0.000

0.066

0.000

1.00

1.80

 

8

-13.5

0.0015

0.000

0.036

0.000

0.99

1.44

+

9

-12.5

0.0005

0.001

0.032

0.000

0.99

1.84

 

10

-11.5

0.0020

0.000

0.079

0.000