<p>Since it is not known at this stage what measures were implemented for each building in regard with eventual flood situations, it does not make sense to purposely exclude the buildings from the flood zone until some kind of general database with that info is built and put into context in your system. Even-more, a lot could happen in a potential flood zone when an extreme event occurs, regardless of the prevention plan by various owners and city management. A risk management model with proper risk probabilities, potential damages and monetary values would eventually be required to better represent the up-to-date context of the site.</p>

CC BY-SA 3.0
2016-01-23T00:59:45.403Z
2016-01-23T00:59:45.403Z
marsisalie
<p>At work (at a local authority), I have a flood zone plan/layer that was created using ArcGIS software from an Elevation Model which has an accuracy of 1 metre. The zone covers an urban area. I cannot get to the resolution of which buildings will be more effected by flood and which won't, but I do have a layer of all buildings.</p>

<p>The question is, whether I should cut the buildings out of the flood zone, and why?</p>

CC BY-SA 3.0
2016-01-22T12:52:09.820Z
what is your ultimate aim? Are you trying to create a layer which only has building that will be flood affected?
Fred
CC BY-SA 3.0
2016-01-22T12:54:55.993Z
Hi Fred, thanks for the reply. I need to create the flood zone at the moment. Later I will use it for risk of population, risk to property and emergency services
Mick
CC BY-SA 3.0
2016-01-22T14:09:38.433Z
@Mick interesting question. I am wondering why you would consider cutting the buildings from the flood zone; especially if you will later model the risks anyway. Could you share with us why it is an issue for you to either cut (or not) the buildings - it will help us to answer/discuss better
marsisalie
CC BY-SA 3.0
2016-01-22T15:02:27.447Z
@fre0n because maybe buildings in general tend to be protected from floods (that's merely an assumption with no base) especially commercial buildings. I guess that the question is whether the majority of buildings would be sealed to water when there is a flood outside
Mick
CC BY-SA 3.0
2016-01-22T17:36:05.383Z
Some buildings are designed for flooding; many are not. There is probably not a universal answer to such a question. But... I imagine that what you should do depends on the purpose of your GIS layer.
Semidiurnal Simon
<water><flooding><urban-climate>
Should I cut buildings from flood zone?
Mick
# Should I cut buildings from flood zone?

(Asked by: username_0 on 2016-01-22)

At work (at a local authority), I have a flood zone plan/layer that was created using ArcGIS software from an Elevation Model which has an accuracy of 1 metre. The zone covers an urban area. I cannot get to the resolution of which buildings will be more effected by flood and which won't, but I do have a layer of all buildings.

The question is, whether I should cut the buildings out of the flood zone, and why?

**Tags:** water, flooding, urban-climate

> **Comments:**
> **username_1**: what is your ultimate aim? Are you trying to create a layer which only has building that will be flood affected?  
> **username_0**: Hi username_1, thanks for the reply. I need to create the flood zone at the moment. Later I will use it for risk of population, risk to property and emergency services  
> **username_2**: @username_0 interesting question. I am wondering why you would consider cutting the buildings from the flood zone; especially if you will later model the risks anyway. Could you share with us why it is an issue for you to either cut (or not) the buildings - it will help us to answer/discuss better  
> **username_0**: @fre0n because maybe buildings in general tend to be protected from floods (that's merely an assumption with no base) especially commercial buildings. I guess that the question is whether the majority of buildings would be sealed to water when there is a flood outside  
> **username_3**: Some buildings are designed for flooding; many are not. There is probably not a universal answer to such a question. But... I imagine that what you should do depends on the purpose of your GIS layer.  

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## 1 answers

### Answer by username_2 on 2016-01-23. Score: 0

Since it is not known at this stage what measures were implemented for each building in regard with eventual flood situations, it does not make sense to purposely exclude the buildings from the flood zone until some kind of general database with that info is built and put into context in your system. Even-more, a lot could happen in a potential flood zone when an extreme event occurs, regardless of the prevention plan by various owners and city management. A risk management model with proper risk probabilities, potential damages and monetary values would eventually be required to better represent the up-to-date context of the site.


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