In addition, code domain checks ensured that only valid codes were assigned to features, and polygon "dissolve" operations identified any cases where adjacent polygons shared the same land use code.
Note also that the residential mapping protocols, described further below, were developed jointly with staff from the Rockingham Planning Commission, Exeter, NH, and were reviewed/approved by staff from the Strafford Regional Planning Commission, Dover, NH.
The mapping of the residential class was subject to additional delineation "rules". As with other classes, features were digitized to visible use boundaries when possible. In these cases, yard edges/natural features guided the delineation. However, where boundaries (or partial boundaries) were indistinct, one of several approaches was utilized:
1a) For indistinct boundaries of houses within 250' of one another and within public water/sewer zones (based on TOWN_SW): a .5-acre circle centered on the edge of the structure furthest from the associated road was used as a guide for the polygon delineation.
1b) For indistinct boundaries of houses within 250' of one another and outside of public water/sewer zones (based on TOWN_SW): the 1a) protocol was applied using a 1-acre circle.
2a) For indistinct boundaries of houses greater than 250' apart and within public water/sewer zones (based on TOWN_SW): a .5-acre box was generated, centered on the structure (or centered in the approximate midpoint of multiple structures on what appeared to be a single parcel). If the structure(s) was within 700' of a road, the box was oriented parallel to the nearest road. In cases where the rotated box intersected the road edge, it was repositioned further away from the road to preserve as much of the box area as possible. Where the box intersected the road buffer, the road edge became the polygon edge. In these cases, the box became somewhat smaller than the original .5-acre. If the house was further than 700' from the road, or did not appear to be associated with a nearby road, the box was not rotated.
2b) For indistinct boundaries of houses greater than 250' apart and outside of public water/sewer zones (based on TOWN_SW): the 2a) protocol was applied using a 1-acre box.
Note that forested areas that were completely enclosed within a developed polygon were assumed to "belong" to the developed polygon, and were generally not distinguished.
1. GRANITID - a 7-digit unique integer assigned sequentially to polygons in the data set.
2. LU - a 2-digit integer describing the land use feature, as follows:
Residential (11) - Individual houses, subdivisions and "in-town" residential areas Industrial/commercial (12) - Urban areas dominated by business operations Mixed urban (13) - Urban areas where commercial enterprise occupies part of a building/block and residential use occurs in another, adjacent part of the building/block. Also, miscellaneous urban uses, e.g. schools, military installations, etc. Transportation/roads (14) - Paved roadways, travel lane width, airports, or other public transportation features Railroads (15) - Railroad beds Auxiliary transportation (16) - Highway medians, clover leafs, etc. Playing fields/recreational (17) - Golf courses, baseball diamonds, football fields, etc. Agriculture (20) - Includes hay fields, row crops, fruit orchards, etc. Farmsteads (24) - Any buildings associated with farms Forested (40) - Land where trees are the dominant cover Water (50) - Open surface water Open wetlands (60) - Wetlands where the dominant vegetation is less than 20' in height Idle/other open (70) - Cemeteries, gravel pits, quarries, old fields, etc.