[CF-metadata] New area_types for LUMIP subgrid land-use tile reporting

From: alison.pamment at stfc.ac.uk <alison.pamment>
Date: Mon, 21 Nov 2016 14:41:05 +0000

Dear Dave,

Thank you for proposing these new area_types for LUMIP.

> primary_and_secondary_land - all primary and secondary vegetation that is not used as cropland or pastureland, should include forests, grasslands, bare ground and
> vegetated wetlands.

I think the name itself is fine and we do already have some entries that refer to primary and secondary deciduous/evergreen trees. I think we should add something into the definition to explain 'primary' and 'secondary' as for the existing terms. Based on their definitions, I'd suggest something like:
'Primary land contains only naturally regenerated species where there are no clearly visible indications of human activities and the ecological processes are not significantly disturbed. Reference: 'Global Forest Resources Assessment: Terms and Definitions', Forestry Department of Food and Agriculture Organization (FAO) of the United Nations, Rome 2010, www.fao.org/forestry/14241-0d7b74f45b0d2cfef31599cc17e4c28cd.pdf. Secondary land has undergone human disturbance and has then recovered naturally. Reference: 'Report of the ad hoc technical expert group on forest biological diversity', United Nations Convention on Biological Diversity, www.cbd.int/forest/definitions.shtml. Primary_and_secondary_land includes all primary and secondary vegetation that is not used as cropland or pastureland, including forests, grasslands, bare ground and vegetated wetlands.

Is this OK? If so, I think the name can be accepted for inclusion in the area types table.

> urban - urban settlements

Is there a reference that we could point to that contains a formal definition of 'urban'? If so, it would be good to include it in the area type definition. I think 'urban' is fine as a name.

You also suggested that we should expand the definition of the existing area_type 'pastures':
> pastures - Includes anthropogenically managed pastureland and rangeland

Currently the definition reads 'Pastures are assumed to be anthropogenic in origin.' Certainly I think we could expand this to 'Pastures are assumed to be anthropogenic in origin. They include anthropogenically managed pastureland and rangeland.'

OK? If so, I think this change can be accepted for inclusion in the area types table.

> Note that in our GMD LUMIP paper, we suggest that subgrid tile variables should be submitted according to the following structure, using Leaf Area Index (LAI) as an
> example: laiLut (lon, lat, time, landusetype4) ? where the landusetype4 dimension has an explicit order of primary_and_secondary_land, crops, pastures, urban. Please
> advise if this is not correct.

This looks perfectly good to me! CF doesn't impose any order on the list of land use types, but it is fine to adopt an additional convention for LUMIP.

> Sum of fractional area for psl+crp+pst+urb may not add up to 1 for grid cells with lakes or glaciers. If model does not represent one of the requested tiles, then should be
> reported as missing value. In cases where more than one land use tile shares information (e.g., if pastureland and cropland share same soil column), then duplicate
> information should be provided for both tiles. Further details on tile reporting available in the LUMIP GMD paper.

Again, I think it is fine to adopt these conventions for LUMIP to supplement the CF conventions.

Best wishes,
Alison

------
Alison Pamment Tel: +44 1235 778065
Centre for Environmental Data Analysis Email: alison.pamment at stfc.ac.uk
STFC Rutherford Appleton Laboratory
R25, 2.22
Harwell Campus, Didcot, OX11 0QX, U.K.


From: CF-metadata [mailto:cf-metadata-bounces at cgd.ucar.edu] On Behalf Of David Lawrence
Sent: 21 October 2016 20:27
To: cf-metadata at cgd.ucar.edu; Elena Shevliakova
Subject: [CF-metadata] New area_types for LUMIP subgrid land-use tile reporting

LUMIP is requesting subgrid output on four land-use tiles (primary_and_secondary_land, crops, pastures, and urban).

area_types for crops and pasture are already defined in the existing cf-conventions.

New area_types required:

primary_and_secondary_land - all primary and secondary vegetation that is not used as cropland or pastureland, should include forests, grasslands, bare ground and vegetated wetlands

urban - urban settlements

Additionally, the existing area_type pastures could include expanded definition

pastures - Includes anthropogenically managed pastureland and rangeland

Note that in our GMD LUMIP paper, we suggest that subgrid tile variables should be submitted according to the following structure, using Leaf Area Index (LAI) as an example: laiLut (lon, lat, time, landusetype4) ? where the landusetype4 dimension has an explicit order of primary_and_secondary_land, crops, pastures, urban.? Please advise if this is not correct.

Sum of fractional area for psl+crp+pst+urb may not add up to 1 for grid cells with lakes or glaciers.? If model does not represent one of the requested tiles, then should be reported as missing value.? In cases where more than one land use tile shares information (e.g., if pastureland and cropland share same soil column), then duplicate information should be provided for both tiles.? Further details on tile reporting available in the LUMIP GMD paper.
Regards,
Dave
Received on Mon Nov 21 2016 - 07:41:05 GMT