nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }

Flow Concentration

NazmulAhasan

HI,

I have a raster layer of a roof (imported from Sketchup then converted to raster by Multipatch tool). I want to find out flow concentration on the roof if rain is falling vertically on the roof. Can you tell the process to do this.

Thanks in advance

Find more posts tagged with

Accepted answers

XanderBakker

It is actually called Flow Accumulation (part of Spatial Analyst). The Help can be found here: ArcGIS Help (10.2, 10.2.1, and 10.2.2)

You should use a cell size small enough to simulate the accumulation. What is the extent of the roof and the cell size you used when converting from the multipatch?

All comments

XanderBakker

It is actually called Flow Accumulation (part of Spatial Analyst). The Help can be found here: ArcGIS Help (10.2, 10.2.1, and 10.2.2)

You should use a cell size small enough to simulate the accumulation. What is the extent of the roof and the cell size you used when converting from the multipatch?

NazmulAhasan

I used a larger cell size 0.5 x 0.5 thought it will help to reduce calculation time. But the raster looked coarse. what cell size will be good for this case anyway?

XanderBakker

This depends on the detail (precision) you are trying to obtain and the precision of the input data (combined with the extent of your roof). If you provide some more info then I can advise you better...

NazmulAhasan

the roof is approx~23 ft in long direction and ~12ft in width.

after all thank's for your effort.

Join the Conversation

Signed in members can post, follow updates, and more. New here? Register a free account.

Quick Links

Community Help
Find useful guides, FAQs, and documents to help you navigate and make the most of Esri Community.