We provide a more comprehensive methodology for the conservation module, click here to view or download the Conservation Analytic Technical Guide.
NOTE - The Conservation Module is available for projects in California only.
The General Conservation metrics give you a high-level understanding of the land cover changes on your project's Base Canvas or Painted Canvas.
The terrestrial carbon storage model is focused on measurement of the stock change of carbon (C) in natural vegetation and soil. This change is associated with various land use changes and land management actions. The model is used to analyze the impact of land use change on above-ground carbon stock in grassland, shrubland, forested ecosystems, and below-ground carbon stock in all environments.
Above-ground carbon includes carbon stocks in live natural vegetation; soil carbon includes carbon stocks that are up to 30 cm below the surface of the soil.
The Agriculture Theme is focused on the conversion of land to and from agricultural and non-agricultural uses. Broadly, metrics are classified into three groups—agricultural capacity, agricultural acreage, and agricultural production.
- Agricultural capacity calculates the impact of development in areas considered important for agriculture.
- Agricultural acreage calculates the change in acreage of agricultural land by agricultural type through expansion of agricultural land on urban or natural lands, and consumption of agricultural land by urban lands.
- Agricultural production represents how the above changes affect the monetary value of crop production in the region studied.
When agricultural lands expand into natural lands, local agricultural production may increase. On the other hand, the expansion of urban lands into agricultural lands can reduce agricultural production. Production value also changes when agricultural lands are converted from one agricultural type to another.
Water Supply and Quality Impacts
The water theme is based on impacts related to four aquatic subthemes: Watershed Integrity, Water Demand (Agricultural and Urban), Groundwater Recharge Potential, and Priority Resource Areas.
Watershed Integrity Watershed integrity has been used by several agencies as an indicator of the “health” of water-related ecosystem processes, functions, and services. Natural land cover within the catchment supports water quality by decreasing the potential for non-point source pollution from runoff. Natural lands proximal to riparian areas are important for filtering out sediment, particles, nitrogen, phosphorous, and other pollutants. The natural land cover in riparian buffers supports natural flow, sediment, and water temperature regimes, and it maintains natural levels of nutrient and organic matter input to streams. (US EPA 2013)
Water Demand (Agricultural and Urban) Land cover changes and associated land use can impact agricultural water demand. When agricultural lands expand into natural lands, agricultural water demand in that area may increase. Alternatively, urban lands expanding into agricultural lands can reduce agricultural water demand and increase regional urban water demand. Demand can also change when lands are converted from one agricultural type to another.
Groundwater Recharge Potential Land cover changes will also impact groundwater recharge potential. When natural, agricultural, or developed open space land cover becomes low-, medium-, or high-density urban, the groundwater recharge potential in that area will be reduced. Alternatively, when low-, medium-, or high-density development is returned to natural, agricultural, or developed open space, recharge potential will be restored. The model is used to measure the net change in volume of potential groundwater recharge. The model does not quantify the relationship between groundwater recharge, actual evapotranspiration (AET), and runoff; nor does it quantify the shift in that relationship that was caused by changes in land use and land management.
Priority Resource Areas The change in acreage by type in water resource priority areas (such as Wetlands, Floodplains, Active River Area, and Drinking Water Source Watersheds) provides the spatial extent of land cover change in those areas. Additionally, users can upload their own priority areas to measure the change in acreage by type within those areas.
Terrestrial Habitat Conservation
The terrestrial habitat models integrate habitat conservation values into a decision-making framework to reveal the impact and benefits of land use change decisions on habitats and associated biodiversity.
Accounting for the impact on terrestrial habitats allows for better assessments of biodiversity and habitat tradeoffs inherent to alternative land use scenarios. The metrics specific to terrestrial habitat conservation accounting reveal how land use in an area contributes to
- habitat value for terrestrial vertebrates,
- species movement potential,
- conservation priority areas.
Model outcomes focus on the landscape's capacity to facilitate or inhibit species' movement and the suitability of an area's land use for supporting terrestrial vertebrates. Scenarios that involve changes to land use can therefore be evaluated on the basis of their impact on habitat suitability and movement potential.
Movement potential is evaluated under the assumptions that natural landscapes generally facilitate movement and converted landscapes generally inhibit movement. The terrestrial habitat models are also used to evaluate the acreage affected by proposed land use change that intersects with predefined and/or user-defined habitat conservation priorities.