M.12 GIS Spatial Requirements
Summary of questions/comments received for the GIS Spatial Requirements section on DHS Interactive and responses provided through October 10, 2008.
| Topic | Comment | Response |
|---|---|---|
| Domains | D_State - Add CNMI D_Surge - D_Surge is listed in the L_Cst_WaterLv table definition but not included in M.12 domain table definitions. D_WvSpec - D_WvSpec is listed in the S_Buoy table definition, but not included in M.12 domain table definitions. D_StudyDetail - D_StudyDetail is defined in M.12 but not given a table definition. |
D_State - This domain table was removed D_Surge - This domain table was added. D_WvSpec - This domain table was added. D_StudyDetail - This Domain table was renamed D_Study_Typ and the attribute field which uses it, STUDY_TYP, was added to S_Profil_Basln and S_Fld_Haz_Ar. |
| S_Nodes | Recommend adding units of measure for elevation and discharge (LEN_UNIT, DISCHARGE_UNIT). | Attribute fields were added to capture this information. LEN_UNIT and DISCH_UNIT |
| S_XS | XS_SRC may be different for different segments of a cross section. It may not always be valid to apply one source to the entire line. There is no longer a place for the station start description in this table. Unless this item will be removed from the Appendix L requirements, we recommend including it here so it can be documented as the data are initially captured. |
The value 'COMBO OF TOPO AND SURVEY' was added to the D_Method domain table. The START_ID field will be added to the S_XS table and the L_Stn_Start lookup table will be added to the DCS table schema before public release. |
| Figures M-9 and M-10 | Figures M-9 and M-10 are very unclear and do not illustrate what is being described. The data in the table of contents of each figure contradicts the titles. | Figure M-9 was removed and replaced with Figure M-10 with a revised title. |
| S_Fld_Haz_Ar | The previous DCS required floodplain boundaries to be submitted as line features not polygons (S_HydraMapping). It is premature to build polygons on a stream-by-stream basis, because they will have to be rebuilt when the streams are merged into countywide files. | The polygons were changed because most automated floodplain generation software generates polygons by default. Accepting the polygons will lessen the burden on the submitter. FEMA recognizes polygons would need to be rebuilt for the final DFIRM product and is willing to reconsider if evidence shows that lines are being produced instead of polygons at this point in the DFIRM production workflow. |
| Profile Baseline | The introductory paragraph to the table definition makes reference to the profile baseline and the stream centerline used in the hydraulic study. This is the first mention of the hydraulic stream centerline. Recommend clarifying the requirements for both the profile baseline and hydraulic stream centerline in the Hydraulics section as well. | The introduction paragraph for the S_Profil_Basln layer has been reworded to "The S_Profil_Basln layer is required for all types of hydraulic analyses. The profile baseline shows the path of flood flows on the FIRM and is representative of the distance between cross sections, nodes, or grids in the hydraulic model. The profile baseline is used for stationing of the profiles found in the FIS." |
Last Modified: Wednesday, 29-Oct-2008 10:18:08 EDT