Engineering / Operational Units of Measure

Climate Regulation – Incoming Solar Radiation Reduction

The potential for a map unit to reduce the amount of incoming solar radiation that reaches the ground surface through shading by vegetative canopy cover.

Measured by:

  • The area weighted site average reduction in incoming solar radiation in units of British Thermal Units (BTU) per square foot per hour (BTU/sf/hr) (area weighted average).

  • The sum of the reduction in incoming solar radiation from all map units in units of BTU per hour (BTU/hr) (site total).

Air Quality – Nitrogen-Oxygen (NOx) Removal

The potential for a map unit to sequester airborne nitrogen-oxygen compounds through interaction with the vegetative canopy cover of trees.

Measured by:

  • The sum of the predicted number of pounds of nitrogen-oxygen compounds that a site is capable of removing over the period of a single year (lbs/year) (total).

Air Quality – Particulate Matter (PM) Removal

The potential for a map unit to sequester airborne particulate matter in the PM10 range through interaction with vegetative canopy cover of trees.

Measured by:

  • The sum of the predicted number of pounds of PM10 that a site is capable of removing over the period of a single year (lbs/year) (total).

Water Provisioning

The amount of depressional surface storage capacity available on a site in which water could be housed and used for business purposes. Note – thresholds for viability (for site management purposes) have been set in the EI platform and must be met for scores to be generated: minimum total volume of storage space = 10,000 gallons; predominant depth = greater than 2 feet; and the storage area must be considered natural.

Measured by:

  • The area weighted average number of gallons per square foot that could be housed in existing depressional areas (where those areas meet the criteria above) if they were spread across the entire site (gallons/sf) (area weighted average).

  • The sum of all gallons that could be housed in existing depressional areas (where those areas meet the criteria above) (gallons) (site total).

Water Quality – Nitrogen Removal

The predicted actual removal of nitrogen compounds from water flowing over a site through vegetative and soil filtration processes given observed potential nitrogen sources.

Measured by:

  • The predicted actual reduction in nitrogen loading in water as an area weighted averaged over the entire site. Units for nitrogen removal in water are milligrams per liter (mg/l) (area weighted average).

AND, the predicted maximum potential removal of nitrogen compounds from water flowing over a site through vegetative and soil filtration processes assuming the presence of nitrogen sources for each map unit.

Measured by:

  • The predicted maximum potential reduction in nitrogen loading in water as an area weighted averaged over the entire site. Units for nitrogen removal in water are milligrams per liter (mg/l) (area weighted average).

Water Quality – Total Suspended Solids (TSS) Removal

The predicted actual removal of total suspended solids from water flowing over a site through vegetative and soil filtration processes given observed potential sources of suspended solids.

Measured by:

  • The predicted actual reduction in total suspended solids loading in water as an area weighted averaged over the entire site. Units for TSS removal in water are milligrams per liter (mg/l) (area weighted average).

AND, the predicted maximum potential removal of total suspended solids from water flowing over a site through vegetative and soil filtration processes assuming the presence of total suspended solids sources for each map unit.

Measured by:

  • The predicted maximum potential reduction in total suspended solids loading in water as an area weighted averaged over the entire site. Units for TSS removal in water are milligrams per liter (mg/l) (area weighted average).

Water Quantity Runoff

The amount of residual storm water on a site after Interception and Infiltration have retained their full potential capacity in a 25-year precipitation event.

Measured by:

  • The total area-weighted average number of inches of runoff that would be expected to come from a site as the result of a 25-year precipitation event (inches of runoff across site).

  • The total number of gallons of runoff that would be expected to come from a site as the result of a 25-year precipitation event (gal).