Deciduous trees · porosity · SUEWS parameter database

browse · records/surfaces/dectr/london--jarvi2011--porosity.yml

Deciduous trees · porositydectr evidence record unreferenced

porosity_min_deciduous0.2

porosity_max_deciduous0.6

porosity dectr generic generic Land-cover class unreferenced

Parameters

Names follow the SUEWS YAML specification; click one for its definition in the configuration reference.

`porosity_min_deciduous`	0.2
`porosity_max_deciduous`	0.6

Provenance evidence

Awaiting sign-off

Assumed · assessed by provenance-audit · 2026-08-24. Agent assessment is evidence preparation, not human verification.

Assessment findings

Name	supported The fixed implementation labels both bounds as deciduous-tree porosity, matching the preserved Deciduous Tree name.
Target	supported The implementation assigns PorMin_dec and PorMax_dec specifically for DecTr and DecidSurf, matching the land_cover.dectr target.
Values	supported SUEWS 2016a hard-codes PorMin_dec as 0.2 and PorMax_dec as 0.6 exactly.
Source	not applicable Järvi et al. describe porosity varying with deciduous-tree LAI but do not state either bound. No parameter publication is claimed for these implementation assumptions, so source unreferenced is the honest declaration. issue #301
Place	supported The hard-coded bounds are applied by the implementation without a site or city condition, so generic is supported. Origin London remains only as legacy migration history.
Representativeness	supported Generic matches fixed model defaults that are not derived for one observational site, city or region.
Applicable Scale	supported The implementation assigns both bounds to the DecTr/DecidSurf land-cover class, supporting land_cover rather than a whole-neighbourhood, facet or material scale.
Method	supported The exact values are hard-coded model defaults with no located scientific derivation, so assumed is appropriate.
Identity	supported Stable path, legacy ID 34240002, values and origin London preserve the migrated row's identity while separating migration history from evidence scope.

Scientific note

Järvi et al. (2011), Section 2.4.1, PDF page 222, say only that tree porosity varies with deciduous-tree LAI and cite Grimmond and Oke (1999b); they publish neither bound. The fixed SUEWS 2016a implementation at https://github.com/UMEP-dev/SUEWS/blob/a234969dc859b6728767135322b9d9fb4b11bba2/SUEWS_translate.f95#L158-L166 instead hard-codes PorMin_dec = 0.2 and PorMax_dec = 0.6 for DecTr. The unchanged values are therefore represented as generic land-cover implementation assumptions: source unreferenced and method assumed. Stable path, legacy ID and origin London retain the migration identity without claiming London evidence.

Model-ready fragment

Paste under land_cover.dectr in a SUEWS YAML configuration; every value carries its citation.

porosity_min_deciduous:
  value: 0.2
  ref:
    ID: unreferenced
    DOI: null
    desc: generic, generic, land_cover
porosity_max_deciduous:
  value: 0.6
  ref:
    ID: unreferenced
    DOI: null
    desc: generic, generic, land_cover