AnsweredAssumed Answered

.bil file to StreamOrder layer.

Question asked by michiner on Oct 20, 2016
Latest reply on Oct 20, 2016 by Dan_Patterson

Hi there!


Currently I'm following a GIS course, via and one of the exercises was to create a streamorder layer.

After following the exercise and completing it without problems, I tried to do the exact exercise for the area where I live.

This is in San Cristobal de las Casas, Chiapas, Mexico.


I found the DEM files (.bil) that I thought I needed for my project and downloaded them. (4 in total)

Vista general   --> here a link to the file that I have downloaded.

In total I downloaded 4 for areas. (E15D51, E15D52, E15D61 and E15D62)

I've merged them together, and started working.


1. Spatial analyst tools --> Hydrology --> Flowdirection.

input=my merged file      


2. Spatial analyst tools --> Hydrology --> Flow Accumulation

Input=Flowdirection layer.      (FLOAT)


3. Spatial analyst tools --> Conditional --> Set-null

Input: FlowAccumulation layer

Expression:  Value < 3000

Output= Flowaccumulation layer


4 Spatial analyst tools --> Hydrology --> Streamorder

Input= Setnull_accumulation_layer

Output = Flowdirection layer

Method: Strahler



The Outcome of this is not really satisfying, as there are only some small parts of the streams visible(non connected).

I'm wondering now what went wrong.

Is it my error, or are the .bil files of to low quality?

(This is what I want to create(only the streams)):  Mapa de la cuenca 


I hope someone can clear this up for me,

I've added a mappackage of my 'work'.


Thanks and Greetings