Fig. 1

Map of the study area and typhoon tracks (TD: tropical depression; TS: tropical storm; STS: severe tropical storm; TY: typhoon; STY: severe typhoon; tr1, tr2 and tr3 are the selected cross sections; M is the selected analysis point; A-A is the selected along section)"

Fig. 2

The wind vector of Nesat (a, 2011) and Usagi (b, 2013), with the dashed box marking the period of typhoon effect"

Fig. 3

The measured surface salinity and river discharge process during Nesat (a) and Usagi (b)"

Fig. 4

Mesh of the large-scale 2-D model (a) and the Modaomen Waterway 3-D model (b)"

Fig. 5

Water level comparison between observed (red) and predicted (black) at different stations during Nesat (2011) and Usagi (2013)"

Fig. 6

Surface salinity comparison between observed (red) and predicted (black) at different stations during Nesat (2011) and Usagi (2013)"

Tab. 1

Summary of numerical experiments performed"

Fig. 7

Horizontal distribution of water level and depth-integrated velocity with 2000 m3·s-1 river discharge during Nesat (2011) in the Modaomen Waterway (the hollow arrows specifying wind speed)"

Fig. 8

Horizontal distribution of water level and depth-integrated velocity with 2000 m3·s-1 river discharge during Usagi (2013) in the Modaomen Waterway (the hollow arrows specifying wind speed)"

Fig. 9

Tidally-averaged volumetric transport of transects at half-day interval with 2000 m3·s-1 river discharge during Nesat (2011) and Usagi (2013), with positive value for seaward and negative value for landward"

Fig. 10

Tidally-averaged salt flux of transects at half-day interval with the 2000 m3·s-1 river discharge during Nesat (2011) and Usagi (2013), with positive value for seaward and negative value for landward"

Fig. 11

Temporal changes of 33-h low-pass-filtered salt flux transects with 2000 m3·s-1 river discharge during Nesat (2011) and Usagi (2013). Positive value means seaward, negative value means landward, and the dashed box marks the typhoon effect period; FE、FT、QFS0、FS refer to the steady shear salt flux, the tidal oscillatory salt flux, the advective salt flux and the net salt flux, respectively"

Fig. 12

Temporal changes of 33-h low-pass-filtered salt flux transects with 1000, 2000 and 4000 m3·s-1 river discharges during Nesat (2011) and Usagi (2013)"

Fig. 13

Salt flux of transect 2 with different river discharges during Nesat (2011) and Usagi (2013)"

Fig. 14

Temporal changes of 33-h low-pass-filtered bottom saltwater intrusion length of different river discharges during Nesat (2011) and Usagi (2013) (2‰)"

Fig. 15

The moment of selected tidal cycle during Nesat (2011) and Usagi (2013) with a, b, c, and d represent flood slack, maximum ebb, ebb slack, and maximum flood, respectively"

Fig. 16

Comparison of vertical velocity and salinity distribution of up-estuary wind case (N-2) and no local wind case (N-nlw) during selected tidal cycle in the Nesat (2011) The dotted line in the figure is the velocity direction distinguishing line, positive value of velocity means seaward, and negative value means landward; z is the water depth value and H is the total water depth value"

Fig. 17

Comparison of vertical velocity and salinity distribution of the moderate down-estuary wind case (U-2) and no local wind case (U-nlw) during the first selected tidal cycle in the Usagi (2013)"

Fig. 18

Comparison of vertical velocity and salinity distribution of the strong down-estuary wind case (U-2) and no local wind case (U-nlw) during the first selected tidal cycle in the Usagi (2013)"

Fig. 19

Comparison of stratification coefficient of the local wind case and no local wind case at point M during Nesat (2011) and Usagi (2013) (The dotted frames mark the period of effect of local wind)"

Fig. 20

Comparison of salt flux of transect 2 of the local wind case and no local wind case during Nesat (2011) and Usagi (2013)"