How to determine the rivers coordinates in the model grid from the geographical coordinates

I have the geographical coordinates (lon, lat) of rivers, I would like to find the coordinates (nx, ny) in the model grid. How can I do it? Is there available script?
I’m grateful for your help.

Hi Bechir

The system that I use is quite manual, I use nestgui in matlab.

First I know the longitude and latitude of the river using Google Earth, then in Matlab I load the grid and look for the lon and lat closest to the river. Finally I open nestgui (Matlab) to go with the river tooling and position myself on the lon and lat found in the previous step, and I correct so that it is not in some corner of the grid, it is not on the land or in the sea.

I hope it helps you,



Hi Cristian,
Thank you for the reply,
I also use a manual method. I simply plot the lon lat of rivers on model grid and then pick the corresponding i an j.
A new plot with the mask to see if they are in the see!
The manual method could work when we have 2-3 rivers, but if the number of rivers becomes like 100, an atraumatic method is requested.
My Best Regards