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Hybrid wavelet transform – MLR and ANN models for river flow prediction: Case study of Brahmaputra river (Pancharatna station) Cover

Hybrid wavelet transform – MLR and ANN models for river flow prediction: Case study of Brahmaputra river (Pancharatna station)

Open Access
|Feb 2024

Figures & Tables

FIGURE 1.

Location of the gauging sitesSource: Khandekar (2014)
Location of the gauging sitesSource: Khandekar (2014)

FIGURE 2.

Observed flow seriesSource: Khandekar (2014)
Observed flow seriesSource: Khandekar (2014)

FIGURE 3.

Wavelet decomposition treeSource: Khandekar (2014).
Wavelet decomposition treeSource: Khandekar (2014).

FIGURE 4.

Flow chart of model developmentSource: own elaboration.
Flow chart of model developmentSource: own elaboration.

FIGURE 5.

Daubechies waveletsSource: Khandekar (2014).
Daubechies waveletsSource: Khandekar (2014).

FIGURE 6.

Effect of Daubechies wavelet order on RMSE (four-day lead time)Source: own elaboration.
Effect of Daubechies wavelet order on RMSE (four-day lead time)Source: own elaboration.

FIGURE 7.

Scatter plot for lead time during different testing periodSource: own elaboration.
Scatter plot for lead time during different testing periodSource: own elaboration.

FIGURE 8.

Time series plot for lead time during different testing period influence of decomposition level on model performanceSource: own elaboration.
Time series plot for lead time during different testing period influence of decomposition level on model performanceSource: own elaboration.

FIGURE 9.

Effect of decomposition level on determination coefficient (R2) for WMLR(db10) modelSource: own elaboration.
Effect of decomposition level on determination coefficient (R2) for WMLR(db10) modelSource: own elaboration.

FIGURE 10.

Flow series comparison between observed, WMLR(db10) and WANN(db10) modelled flow for monsoon seasonSource: own elaboration.
Flow series comparison between observed, WMLR(db10) and WANN(db10) modelled flow for monsoon seasonSource: own elaboration.

Correlation coefficients for the flow series

Output* (Qt+n)Input (Qt−j)*
QtQt−1Qt−2Qt−3Qt−4Qt−5Qt−6Qt−7Qt−8Qt−9
Qt+20.9830.9710.9570.9420.9290.9150.9030.8910.8800.871
Qt+40.9570.9420.9280.9150.9020.8910.8800.8700.8620.854
Qt+70.9150.9020.8910.8800.8700.8620.8540.8460.8390.832
Qt+140.8460.8390.8320.8250.8180.8120.8050.7990.7920.784

Values of statistical parameters for 14-day lead time

Model typeTraining periodTesting periodOptimum ANN structure
RMSER2MAEBIASSIRMSER2MAEBIASSI
ANN5 704.970.7654 035.671.0140.3537 084.210.6735 116.371.0680.4334-2-1
MLR4 584.370.8483 204.371.0000.2835 415.770.8093 630.940.9990.333
WANN-db1l54 173.090.8742 765.271.0070.2584 913.550.8433 425.921.0360.30024-4-1
WMLR-db1l54 761.190.8363 215.261.0000.2946 050.480.7623 886.880.9990.371
WANN-db2l53 071.960.9322 062.781.0040.1904 716.300.8553 017.381.0380.28824-3-1
WMLR-db2l54 037.440.8822 571.671.0000.2494 876.840.8453 109.410.9990.299
WANN-db3l52 420.950.9581 737.071.0140.1493 848.560.9042 663.881.0310.23524-2-1
WMLR-db3l53 172.170.9272 083.461.0000.1964 770.310.8522 694.260.9990.292––
WANN-db8l51 922.740.9731 353.081.0120.1193 746.150.9082 190.531.0200.22924-2-1
WMLR-db8l51 985.330.9711 325.191.0000.1232 612.090.9551 731.460.9990.160
WANN-db10l52 225.740.9641 600.630.9950.1383 539.600.9182 287.830.9860.21724-3-1
WMLR-db10l51 670.310.9791 137.671.0000.1032 196.460.9681 435.571.0000.134

Values of statistical parameters for seven-day lead time

Model typeTraining periodTesting periodOptimum ANN structure
RMSER2MAEBIASSIRMSER2MAEBIASSI
ANN4 308.720.8662 801.051.0020.2665 185.330.8253 441.991.0320.3184-3-1
MLR4 490.920.8542 986.841.0000.2775 376.870.8113 429.750.9990.331
WANN-db1l52 830.190.9421 961.301.0040.1754 131.690.8892 942.381.0160.25424-3-1
WMLR-db1l53 122.620.9291 942.731.0000.1934 123.650.8892 415.440.9990.254
WANNdb2l52 038.560.9701 408.021.0040.1262 894.020.9451 927.131.0240.17824-2-1
WMLR-db2l52 623.550.9501 617.631.0000.1623 193.400.9331 937.760.9990.196
WANN-db3l51 683.520.9791 151.421.0030.1042 525.320.9581 639.741.0130.15524-3-1
WMLR-db3l52 129.550.9671 336.341.0000.1322 987.570.9421 640.060.9990.184
WANN-db8l51 313.630.987871.910.9990.0812 038.330.9731 233.970.9970.12524-2-1
WMLR-db8l51 318.740.987837.081.0000.0821 702.960.9811 042.410.9990.105
WANN-db10l51 187.510.989792.060.9990.0731 929.580.9751 060.011.0050.11924-2-1
WMLR-db10l51 167.650.990733.491.0000.0721 585.020.984881.761.0000.097

Values of statistical parameters for two-day lead time

Model typeTraining periodTesting periodOptimum ANN structure
RMSER2MAEBIASSIRMSER2MAEBIASSI
ANN1 764.660.9771 044.281.0020.1092 463.330.9601 401.831.0140.1522-8-1
MLR1 828.260.9761 058.121.0000.1132 535.960.9581 293.191.0000.156
WANN-db1l51 199.430.989757.471.0080.0741 795.990.9791 144.511.0180.11012-2-1
WMLR-db1l51 228.250.989680.191.0000.0761 758.640.980913.411.0000.109
WANN-db2l4960.300.993540.141.0010.0591 415.360.987796.431.0070.08710-2-1
WMLR-db2l51 093.660.991595.741.0000.0681 478.740.986769.430.9990.091
WANN-db3l4813.840.995469.561.0010.0501 202.330.990698.701.0070.07410-3-1
WMLR-db3l5909.810.994510.231.0000.0561 311.380.989629.760.9990.081
WANN-db8l5553.070.998368.931.0000.0341 054.100.992543.921.0000.06512-2-1
WMLR-db8l5526.830.998296.781.0000.033775.110.996406.200.9990.048
WANN-db10l5481.400.998298.510.9990.030933.060.994436.490.9990.05712-2-1
WMLR-db10l5471.990.998261.791.0000.029751.870.996369.691.0000.046

Statistical properties of flow data

Statistical parameterTrainingTestingAll
Qmean [m3·s−1]16 15916 23616 161
Qmax [m3·s−1]59 83276 23676 236
Qmin [m3·s−1]2 6281 7231 723
Sd [m3·s−1]11 78312 38811 965
Cx0.7260.9680.809

Optimal input combination

Lead time [day]Input parameter*Output parameter** Q(t+n)
2Qt, Q(t−1)Q(t+2)
4Qt, Q(t−1), Q(t−2), Q(t−3)Q(t+4)
7Qt, Q(t−1), Q(t−2), Q(t−3)Q(t+7)
14Qt, Q(t−1), Q(t−2), Q(t−3)Q(t+14)

Effect of decomposition level on determination coefficient (R2) for WMLR-db10 model (testing period)

Two-day lead timeFour-day lead timeSeven-day lead time14-day lead time
Model typeR2Model typeR2Model typeR2Model typeR2
WMLR-db10l10.976WMLR-db10l10.914WMLR-db10l10.824WMLR-db10l10.656
WMLR-db10l20.995WMLR-db10l20.966WMLR-db10l20.861WMLR-db10l20.684
WMLR-db10l30.996WMLR-db10l30.990WMLR-db10l30.967WMLR-db10l30.760
WMLR-db10l40.996WMLR-db10l40.991WMLR-db10l40.983WMLR-db10l40.953
WMLR-db10l50.996WMLR-db10l50.991WMLR-db10l50.984WMLR-db10l50.968

Values of statistical parameters for four-day lead time

Model typeTraining periodTesting periodOptimum ANN structure
RMSER2MAEBIASSIRMSER2MAEBIASSI
ANN3 133.090.9292 067.411.0050.1943 890.350.9012 566.071.0310.2394-8-1
MLR3 136.830.9291 988.841.0000.1943 932.060.8992 274.721.0000.243
WANN-db1l51 918.220.9731 229.161.0080.1182 590.840.9561 717.581.0180.15924-3-1
WMLR-db1l52 088.670.9681 268.591.0000.1292 909.440.9451 618.861.0000.179
WANN-db2l51 431.040.985868.661.0010.0881 986.380.9741 137.201.0090.12224-2-1
WMLR-db2l41 922.490.9731 160.031.0000.1192 342.130.9641 354.140.9990.144
WANN-db3l51 280.060.988790.251.0010.0791 683.590.9821 034.971.0040.10424-2-1
WMLR-db3l51 528.750.983924.381.0000.0942 067.670.9721 084.630.9990.127
WANN-db8l4962.640.993601.761.0010.0591 465.350.986774.111.0000.09020-2-1
WMLR-db8l5940.030.994556.621.0000.0581 213.320.990664.470.9990.075
WANN-db10l5822.670.995527.851.0030.0511 477.120.986755.191.0040.09124-2-1
WMLR-db10l5785.370.995460.221.0000.0481 174.800.991612.691.0000.072

Values of statistical parameters for WMLR(db10) model for monsoon season (June to September) in testing period

YearRMSER2MAEBIASS.I.
Two-day lead time
1997890.550.995596.9661.0000.034
19981 448.880.995767.8020.9990.042
19991 070.200.996629.8990.9990.034
Four-day lead time
19971 572.650.9841 072.411.0000.059
19982 188.390.9891 153.710.9990.063
19991514.680.992968.890.9980.048
Seven-day lead time
19972 243.790.9671 667.900.9980.084
19982 971.270.9801 677.601.0010.086
19991 797.460.9891 209.730.9990.058
14-day lead time
19973 035.860.9382 292.431.0020.115
19983 722.210.9672 295.271.0060.111
19992 588.930.9761 972.250.9980.084

Percent improvement in RMSE with increase in wavelet order from db1 to db10

Lead time [day]Improvement in RMSE [%]
257.25
454.66
761.56
1455.30
DOI: https://doi.org/10.22630/srees.5258 | Journal eISSN: 2543-7496 | Journal ISSN: 1732-9353
Language: English
Page range: 69 - 94
Submitted on: Sep 2, 2023
Accepted on: Jan 19, 2024
Published on: Feb 28, 2024
Published by: Warsaw University of Life Sciences - SGGW Press
In partnership with: Paradigm Publishing Services

© 2024 Sachin Dadu Khandekar, Dinesh Shrikrishna Aswar, Pandurang Digamber Sabale, Varsha Sachin Khandekar, Mohankumar Namdeorao Bajad, Shivakumar Khaple, published by Warsaw University of Life Sciences - SGGW Press
This work is licensed under the Creative Commons Attribution-NonCommercial 4.0 License.