River inflow direction

[APJ]

Can anyone please help me with the river inflow directions? If the river flows from east to west, what should its direction be? Or if the river is flowing from North to South, what directions should I prescribe? I went through the wikiroms (https://www.myroms.org/wiki/River_Runof ... _direction) but did not get much clarity. I hope someone can simplify the river direction explanation.

[wilkin]

The river_direction variable specifies whether flow is crossing a u-face (river_direction = 0), a v-face (river_direction = 1) or enters as a flux divergence in the center of the cell at a rho-point (river_direction = 2). That is spelled out here: https://www.myroms.org/wiki/River_Runof ... _direction.

While river_direction flag equal to 0 or 1 specifies the cell velocity face the flow crosses, the actual direction of the flow depends on the sign of the river_transport, which is explained here: https://www.myroms.org/wiki/River_Runof ... _transport.

[APJ]

Thanks wikin. So if I specify river direction as 1 then the flow is from south to north, and if I provide -1 it indicates the river flow from north to south. Is my understanding correct?

[wilkin]

No, that is incorrect. For flow through the v face river_direction = 1 but if flow is in the negative y direction then river_transport is negative.