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Sakleshpur Annual Rainfall Data - Stochastic Hydrology - Lecture Notes, Study notes of Mathematical Statistics

The main points which I found very interesting are: Sakleshpur Annual Rainfall Data, Correlogram, Power Spectrum, Partial Auto Correlation, Parameters for Selected Model, Significance of Residual Mean, Significance of Periodicities, Whittle’s White Noise Test

Typology: Study notes

2012/2013

Uploaded on 04/20/2013

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CASE STUDIES -
ARMA MODELS
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Download Sakleshpur Annual Rainfall Data - Stochastic Hydrology - Lecture Notes and more Study notes Mathematical Statistics in PDF only on Docsity!

CASE STUDIES -

ARMA MODELS

3

Case study – 5

4

Sakleshpur Annual Rainfall Data (1901-2002)

Time (years)

Rainfall in mm

Case study – 5 (Contd.)

6

PAC function Power spectrum

x

5

2 2

k k

N

I k α β

k

k

N

1

2

cos 2

n

k t k

t

x f t

N

α π

=

=

1

2

sin 2

n

k t k

t

x f t

N

β π

=

=

P

p

  • φ

p

= ρ

p

Auto Correlations

Partial Auto Correlation

Auto Correlation

function

Case study – 5 (Contd.)

7

Case study – 5 (Contd.)

9

  • Significance of residual mean

Model η(e) t

(N )

ARMA(5,0) 0.000005 1.

Significance of periodicities:

Case study – 5 (Contd.)

10

Periodicity η F

(2, N-2 )

st

nd

rd

th

th

th

Case study – 5 (Contd.)

12

 - AR(1) 9. Model Likelihood - AR(2) 8. - AR(3) 8. - AR(4) 9. 
  • AR(5) 9.
    • AR(6) 9.
  • ARMA(1,1) 8.
  • ARMA(1,2) 8.
  • ARMA(2,1) 7.
  • ARMA(2,2) 5.
  • ARMA(3,1) 6.
  • ARMA(3,2) 6. - AR(1) 1. Model MSE - AR(2) 1. - AR(3) 1. - AR(4) 1. - AR(5) 1. - AR(6) 1.
    • ARMA(1,1) 1.
  • ARMA(1,2) 1.
    • ARMA(2,1) 1.
    • ARMA(2,2) 1.
    • ARMA(3,1) 1.
    • ARMA(3,2) 27.

Case study – 5 (Contd.)

13

  • ARMA(1, 2) is selected with least MSE value for

one step forecasting

  • The parameters for the selected model are as

follows

1

1

2

Constant = -0.

Significance of periodicities:

Case study – 5 (Contd.)

15

Periodicity η F

(2, N-2 )

st

nd

rd

th

th

th

Case study – 5 (Contd.)

16

  • Whittle s white noise test:

Model η F

(n1, N–n1)

ARMA(1, 2) 0.3605 1.

Summary of Case studies

Case study-1:Time series plot

18

Daily rainfall data of Bangalore city Monthly rainfall data of Bangalore city

0 5 10 15 20 25 30 35

500

600

700

800

900

1000

1100

1200

1300

1400

Yearly rainfall data of Bangalore city

Summary of Case studies

Case study-1: Correlogram

19

0 100 200 300 400 500 600

-0.

-0.

0

Lag

Sample Autocorrelation

Sample Autocorrelation Function

Daily rainfall data of Bangalore city Monthly rainfall data of Bangalore city

Yearly rainfall data of Bangalore city

Time (months)

Flow in

cumec

Summary of Case studies

Time series plot

21

  1. Monthly stream flow data of a river

Time

Flow in

cumec

  1. Monthly stream flow data for Cauvery
    1. Sakleshpur Annual Rainfall Data

Summary of Case studies

Correlogram

22

  1. Monthly stream flow data for Cauvery 4. Monthly stream flow data of a river
    1. Sakleshpur Annual Rainfall Data