G.33 Update of D_AREA_GEOM
Estimated Recurrence Time: As required.
The D_AREA_GEOM contains the boundaries (as polygons) for the various partner agencies, the ORMGP study area as well as the extent of geologic and hydrogeologic models. Many of these include a buffered region as well. This information is stored in two columns: GEOM and GEOM_WKB. The former holds the default ‘geometry’ type for Microsoft SQL Server while the latter has been stored in the ‘Well Known Binary’ format.
The GEOM field is populated through any external GIS software that supports the native geometry format. The GEOM_WKB is then populated using V_SYS_AREA_GEOM_WKB (using GEOM as a source).
Projections can be checked through
select area_id ,geom.STSrid From d_area_geom
which returns the EPSG projection numeric for each record/object. This should conform to the code ‘26917’ (UTM Zone 17, NAD83). If these have been incorrectly assigned (from the external source), the specific records can be updated using
update d_area_geom set geom.STSrid= 26917 where area_id= 76
The example here is updating the ORMGP Boundary 5km buffer layer.