I wonder if it is possible to set a cell as starting point and then calculate its lowest neighbour; the neighbour cell does not necessarily have to be lower than the original cell. Then I would like the program to do the same calculation from these two cells and mark the cell with the lowest value connected to one of the two other cells and so on.
I have managed to do it manually by converting the raster cells to a polygon grid and work through the whole raster by watching the attribute table, mark the lowest neighbour and so on but it is off course very time consuming.
I have tried to use the Cost Distance tools but they do not seem to fix the problem. Maybe I can explain it better with an example:If rain falls over the elevation raster it will travel to the lowest point. If the rain keeps coming it will start to spread from this point to one of it's eight neighbours, the one with the lowest elevation value. Then it will have 15 alternative neighbours to spread to in the third step and so on. Cost Distance only seem to add the elevations which does not help me i am afraid. I have been able to do it manually by making a polygon grid from the raster, do a select by location to get all cells around the first cell and then a select by attributes to get the one with the lowest elevation and so on. I think there must be some easier way to do this in raster tough. Or maybe I can automate the process of select by attributes followed by select by location followed by another select by attributes and so on? I am very thankful for any ideas you might have since i am rather stuck at the moment...Greetings!