Error in the indication of nodeidx in 'Exploring river discharge' notebook

[roalva82]

Under section 'How to locate reach and node identifiers by river name', I believe that the second last line should read as follows: node_identifiers = results['nodes']['node_id'][node_idx]

instead of the current version which reads: node_identifiers = results['nodes']['node_id'][:]

I hope this helps. Thank you for the useful notebook!