Code Table 4.2 - New category "Urban areas" within discipline 2 "Land Surface Products"

[sebvi]

Summary and purpose

ECMWF is proposing a new category "Urban areas" within the discipline "Land Surface Products".

Action proposed

The team is kindly asked to review and approve the contents for inclusion within the next update to the WMO Manual on Codes.

Discussions

In the context of the recent developments of accurate modelling of Urban areas, we would like to request a new category "Urban areas" to host new parameters specific to Urban modelling.
The first set of parameters includes Urban cover, Road cover, Building cover, Building height, Vertical-to-horizontal area ratio, and standard deviation of Building height. We foresee the need of additional parameters in the near future.

Detailed proposal

Add a new Category "1 - Urban areas" within the discipline "2 - Land Surface products" in Code table 4.2

Code	Meaning	Units	Description
0	Urban Cover	proportion	This parameter is the fraction of the grid box (0-1) that is covered with an urban surface.This parameter includes all impervious and artificial surfaces(e.g. roads, buildings, parking lots, etc.).
1	Road Cover	proportion	This parameter is the fraction of the grid box (0-1) that is covered with a flat impervious surface(including paved areas and bridges).
2	Building Cover	proportion	This parameter is the fraction of the grid box (0-1) that is covered with an elevated impervious surface(e.g. buildings).
3	Building height	m	This parameter contains the average building height (vertical) within the grid box.
4	Vertical-to-horizontal area ratio	m2 m-2	This parameter is the ratio of total building wall area to the plan area of urban cover.
5	Standard deviation of building height	m	This parameter is the standard deviation of building heights of the grid box.
6 - 191	Reserved
192 -254	Reserved for local use
255	Missing

[amilan17]

re: https://github.com/wmo-im/CCT/wiki/Teleconference-26-and-28.4.2022

No objections to new category, Sebastien will also update issue with a table listing all the categories. Branch to be added.

@amilan17 create branch

[sebvi]

branch updated

[amilan17]

@SibylleK propose another code building cover in a different way

[amilan17]

https://github.com/wmo-im/CCT/wiki/Teleconference-8.6.2022 notes:

Sibylle spoke with colleagues and extra parameter is not needed. 

branch is ready, @marijanacrepulja validate

[marijanacrepulja]

@sebvi category name is slightly different between proposal and the branch.
In the proposal is Urban area
In the branch is Urban areas

Which name do you want to use?

[amilan17]

I think 'Urban areas' sounds better, 'area' sounds more related to the geometry of the urban space.

[sebvi]

yes! @amilan17 and @marijanacrepulja : when doing the branch I also thought it should be areas so I used that but did not update the ticket. will do now

[marijanacrepulja]

@amilan17 the branch is ready, please review the branch and move to "Ready to FT"