Establishment of fire hose


#1

Hello
I am looking to use ORS TOOLS on QGIS 3.8.1 to study firefighting distances for fire defense.
The pipes are established on motorized roads over a maximum distance of 200 meters.
When I use ORS TOOLS, the distances are wrong:
Already the polygon is not restricted to the road and moreover the lengths do not respect the distances of 200 meters.

Am I making a mistake while configuring the tool?
:
{ ‘INPUT_FIELD’ : None, ‘INPUT_METRIC’ : 1, ‘INPUT_POINT’ : ‘-236311.158060,6095143.369095 [EPSG:3857]’, ‘INPUT_POINT_LAYER’ : None, ‘INPUT_PROFILE’ : 0, ‘INPUT_PROVIDER’ : 0, ‘INPUT_RANGES’ : ‘200’, ‘OUTPUT’ : ‘TEMPORARY_OUTPUT’ }


#2

Hi,
yes, that’s a known issue for small isochrones.

@adam , there’ll be a fix for this in the next release right?


#3

There should be a partial fix, but a full fix requires a complete rewrite of how some aspects of isochrones work. In general, such small distances are not recommended for isochrones.