Description: For each development type (as categorized by DLCD in their Development Registry), a magnitude and distance of impact is assigned. The 'magnitude' describes the proportion of habitat value lost immediately adjacent to the impact, while 'distance' describes the distance away from the development where the impact goes to '0' (i.e. no sage-grouse behavioral modification). Two simplying assumptions underlie these data:Impacts are assumed to decay linearly.Landforms are not accounted for. Hence, the impacts radiate uniformly away from the source of impact. The indirect impacts at any location are cumulative, meaning that the indirect imapct of all developments within ~ 5km are included. However, where multiple impact zones overlap, they are not summed. Rather, the first impact is given full value, and each subsequent impact is given a reduced value. This is to ensure that the initial development in pristine habitat is given the maximum penalty, while impacts from subsequent developments are scored less harshly. This is to incentivize development towards areas of existing impact, and away from areas free of impacts.This 'discount' surface is used as a multiplier with the habitat value dataset (VegState). Therefore, lowest values are adjacent to the impact, while largest values are further away. This may be counter-intuitive to casual observers, so a companion dataset is created for display purposes as the inverse of these data. This raster is created with a script that is part of the Habitat Quantification Tool, and built using the polygons in the 'Development_Existing' Feature Class. Therefore, this dataset will need to re-created each time there is an addition/edit to the 'Development_Existing' Feature Class. These data represent the inverse of the Development Impacts Discount Raster and the metadata shown here was imported from the Development Discount dataset.
Copyright Text: The Nature Conservancy The Willamette Partnership