Fig. 1

Study area and station locations"

Fig. 2

The digital elevation model of the Pearl River Estuary"

Fig. 3

Model calculation section and grid. (a) Partial view of 1D area; (b) partial view of 2D area"

Fig. 4

Manning coefficient value of the main river channel in flood season (a) and dry season (b)"

Fig. 5

Verification of tidal level along the tidal reach of the West River"

Fig. 6

Time series of river discharge and tidal levels at eight observation stations along the tidal reach of the West River in 2015. (a) Flow at Wuzhou station; (b) tide levels at observation stations; (c) tide levels at stations of Makou, Tianhe, and Denglongshan from February to March"

Fig. 7

Time series of river discharge and tidal levels at eight observation stations along the tidal reach of the West River in 2016. (a) Flow at Wuzhou station; (b) tide levels at observation stations; (c) tide levels at stations of Makou, Tianhe, and Denglongshan from February to March"

Fig. 8

Time series of river discharge and tidal levels at eight observation stations along the tidal reach of the West River in 2017. (a) Flow at Wuzhou station; (b) tide levels at observation stations; (c) tide levels at stations of Makou, Tianhe, and Denglongshan from February to March"

Fig. 9

Time series of daily average tide level considering river discharges (a) and not considering river discharges (b) in 2015 at stations of Makou, Tianhe, and Denglongshan"

Fig. 10

Time series of daily average tide level considering river discharges (a) and not considering river discharges (b) in 2016 at stations of Makou, Tianhe, and Denglongshan"

Fig. 11

Time series of daily average tide level considering river discharges (a) and not considering river discharges (b) in 2017 at stations of Makou, Tianhe, and Denglongshan"

Fig. 12

Tide levels of 48 h at stations of Makou, Tianhe, and Denglongshan in 2015"

Fig. 13

Tide levels of 48 h at stations of Makou, Tianhe, and Denglongshan in 2016"

Fig. 14

Tide levels of 48 h at stations of Makou, Tianhe, and Denglongshan in 2017"

Fig. 15

Extreme tide levels at eight hydrographic stations along the tidal reach of the West River from 2015 to 2017. The grey lines indicate the time series of tide levels for about 30 days. The sky blue lines indicate the daily average tide levels. The red dots indicate that the lowest tide level occurs during spring tide. The green dots indicate that the highest tide level occurs during spring tide. The orange dots indicate that the highest tide level occurs during mid-tide, and the dark blue dots indicate that the lowest tide level occurs during mid-tide"

Tab. 1

The number of occurrences of extreme tide levels in different periods at the hydrographic stations along the tidal reach of the West River from 2015 to 2017"

Fig. 16

Variations of extreme tide levels at the hydrographic stations along the tidal reach of the West River from 2015 to 2017"

Fig. 17

Time series of tide range at eight hydrographic stations along the tidal reach of the West River in 2015"

Fig. 18

Time series of tide range at eight hydrographic stations along the tidal reach of the West River in 2016"

Fig. 19

Time series of tide range at eight hydrographic stations along the tidal reach of the West River in 2017"

Fig. 20

Monthly average tide range at eight hydrographic stations along the tidal reach of the West River from 2015 to 2017"

Fig. 21

Time series of tide range (a) and water level (b) changes at stations of Makou, Gaoming, and Ganzhu from October to November, 2015"

Fig. 22

Correlation of the water level at the hydrological station along the tidal reach of the West River with the river discharge at Wuzhou Station from 2015 to 2017"

Fig. 23

Correlation of the water level at the hydrological station along the tidal reach of the West River with the ocean tide levels from 2015 to 2017"

Tab. 2

Linear correlation coefficients of water levels at hydrological stations along the tidal reach of the West River with the river discharge at Wuzhou Station and the Ocean tide levels"