NHD Applications Symposium December 11-14,2000 - Austin, TX The National Hydrography Dataset: A Look at Database Structures Steve Andrews INDUS Corporation

NHD Applications SymposiumDecember 11-14,2000 - Austin, TX

The National Hydrography Dataset: A Look at Database Structures

Steve AndrewsINDUS Corporation

Vienna, [email protected]


“An expert is a man who has made allthe mistakes, which can be made, ina very narrow field.”

Niels Bohr


Overview

• Data Formats– FOD, NHDinARC, NHDinSHP, NHDinSDE,

NHDinArcHydro?• NHD RAD Overview• Events as Shapes• Data Access

– ArcIMS, Data Download, etc.


Format Overview• The FOD (Feature Operational Database)• NHDinARC• NHDinSHP• NHDinSDE• NHDinArcHydro


The FOD

• Master copy of the NHD• Features and relationships• No measures• Primarily designed for maintenance


NHDinARC

• Available only in cataloging unit (CU) “Cans”• Features can appear in more than one “can”• GIS route system• Measures• Includes (ArcInfo generated) topology• Has ArcInfo specific structures• Can be difficult to put together (appendNHD.aml)


NHDinSHP

• Can be created from NHDinARC using NHDARC2SHP

• Carries ArcInfo constructs, but they are not required*

• Routes become measured shapes• INFO files are DBFs• Can be difficult to put together


NHDinSDE (RAD)

• Appended together*• Carries all ArcInfo constructs, but they are

not required*• Routes are measured shapes• INFO files are Oracle tables


NHD RAD Design Overview

• Oracle 8i RDBMS, ArcSDE 8.0.2 spatial indexing system

• 13 NHD SDE layers; 8 related NHD attribute tables

• 2 event tables and 1 event SDE layer per system of events*

• NHD metadata stored outside of Oracle; Event metadata stored in Oracle


AREA:N(18,5)PERIMETER:N(18,5)NHDPT_:N(11)NHDPT-ID:N(11)COM_ID:N(11)FTYPE:C(24)FCODE:F(5)GNIS_ID:C(8)NAME:C(99)

POINT.DBF (SHP)

NHD Point Shapes

AREA:N(18,5)PERIMETER:N(18,5)DOM_:N(11)DOM-ID:N(11)DUU_ID:N(11)DUU_NAME:C(40)DUU_DATE:date

DUUDOM.DBF (SHP)

FNODE_:N(11)TNODE_:N(11)LPOLY_:N(11)RPOLY_:N(11)LENGTH:N(18,5)NHDDUU_:N(11)NHDDUU-ID:N(11)

DUUARC.DBF (SHP)

AREA:N(18,5)PERIMETER:N(18,5)NHDDUU_:N(11)NHDDUU-ID:N(11)

DUUPOLY.DBF (SHP)

NHD Digital Update Unit (DUU) Shapes

RAD Event Tables

EVENT_ID:C(19)F_MEAS(6,2)T_MEAS:N(6,2)EOFFSET:N(12,8)DUU_ID:N(10)RCH_CODE:C(14)RCH_DATE:DATEATTR_PRG:C(30)ATTR_VAL:C(20)ENTITY_ID:C(60)STATE:C(2)META-ID:C(18)

Linear Event Table

EVENT_ID:C(19)P_MEAS(6,2)EOFFSET:N(12,8)DUU_ID:N(10)RCH_CODE:C(14)RCH_DATE:DATEATTR_PRG:C(30)ATTR_VAL:C(20)ENTITY_ID:C(60)STATE:C(2)META-ID:C(18)

Point Event Table

EVENT_ID:C(19)DUU_ID:N(10)RCH_CODE:C(14)RCH_DATE:DATEATTR_PRG:C(30)ATTR_VAL:C(20)ENTITY_ID:C(60)STATE:C(2)META-ID:C(18)

Waterbody Event Table (SHP)

Event Metadata Table

Structure Under Revision

Event Metadata

CU_METADATAQUAD_METADATANHD.met

NHD Metadata Files

NHD Metadata System Files

REL_COM_ID:N(11)COM_ID_1:N(11)COM_ID_2:N(11)REL_TYPE:C(99)

FREL.DBF

SUBCLASS:C(13)SUBCLASS_:N(11)POLY_:N(11)

RXP.DBF

REL_COM_ID:N(11)COM_ID_1:N(11)COM_ID_2:N(11)SEQUENCE:N(3)DIRECTION:N(5)DIR_TEXT:C(24)DELTA_LVL:N(5)

RFLOW.DBF

FCODE:N(5)FTYPE:C(24)DESCRIPT:C(130)ABW:C(32)ANT:C(32)CDY:C(32)CGC:C(32)COM:C(32)COS:C(32)FLO:C(32)GTT:C(32)HYC:C(32)HZT:C(32)IAT:C(32)ICS:C(32)IMC:C(32)OPS:C(32)PIT:C(32)POA:C(32)POT:C(32)PRD:C(32)RET:C(32)RTS:C(32)SOC:C(32)STT:C(32)SZT:C(32)WAC:C(32)WAT:C(32)WIT:C(32)

FCODE.DBF

NHD Table Extensions

DUU2FEA.DBF

DUU_ID:N(11)COM_ID:N(11)

NHD Digital Update Unit (DUU) Table Extensions

AREA:N(18,5)PERIMETER: N(18,5)WB_:N(11)WB-ID: N(11)COM_ID:N(11)(alternate WB_COM_ID)RCH_COM_ID:N(11)FTYPE:C(24)FCODE:N(5)ELEV:N(12,1)STAGE:C(24)SQ_KM:N(18,3)GNIS_ID:C(8)NAME:C(99)

WB.DBF (SHP)

AREA:N(18,5)PERIMETER:N(18,5)RCH_:N(11)RCH-ID:N(11)COM_ID:N(11)RCH_CODE:C(14)RCH_DATE:dateSQ_KM:N(18,3)GNIS_ID:C(8)NAME:C(99)

AREARCH.DBF (SHP)

AREA:N(18,5)PERIMETER: N(18,5)NHD_:N(11)NHD-ID:N(11)

POLY.DBF (SHP)

AREA:N(18,5)PERIMETER:N(18,5)LM_:N(11)LM-ID:N(11)COM_ID:N(11)FTYPE:C(24)FCODE:N(5)ELEV:N(12,1)STAGE:C(24)SQ_KM:N(18,3)GNIS_ID:C(8)NAME:C(99)

AREALM.DBF (SHP)

RCH_:N(11)RCH-ID:N(11)COM_ID:N(11)RCH_CODE:C(14)RCH_DATE:dateLEVEL:N(5)METERS:N(12)GNIS_ID:C(8)NAME:C(99)

LINEARRCH.DBF (M_SHP)

DRAIN_:N(11)DRAIN-ID:N(11)COM_ID:N(11)RCH_COM_ID:N(11)WB_COM_ID:N(11)FTYPE:C(24)FCODE:N(5)METERS:N(12)

DRAIN.DBF (SHP)

LM_:N(11)LM-ID:N(11)COM_ID:N(11)FTYPE:C(24)FCODE:N(5)METERS:N(12)GNIS_ID:C(8)NAME:C(99)

LINEARLM.DBF (M_SHP)

FNODE_:N(11)TNODE_:N(11)LPOLY_:N(11)RPOLY_:N(11)LENGTH:N(18,5)NHD_:N(11)NHD-ID:N(11)

ARC.DBF (SHP)

ROUTELINK_:N(11)ARCLINK_:N(11)F-MEAS:N(12,3)T-MEAS:N(12,3)F-POS:N(12,3)T-POS:N(12,3)RCH_:N(11)RCH-ID:N(11)

SECRCH.DBF

ROUTELINK_:N(11)ARCLINK_:N(11)F-MEAS: N(12,3)T-MEAS:N(12,3)F-POS: N(12,3)T-POS: N(12,3)DRAIN_:N(11)DRAIN-ID:N(11)

SECDRAIN.DBF

ROUTELINK_:N(11)ARCLINK_: N(11)F-MEAS:N(12,3)T-MEAS: N(12,3) F-POS: N(12,3)T-POS: N(12,3)LM_: N(11)LM-ID: N(11)

SECLM.DBF

ARC_:N(11)NHD_:N(11)NHD-ID:N(11)COM_ID:N(11)FTYPE:C(24)ABOVE_ID:N(11)BELOW_ID:N(11)

NODE.DBF (SHP)

NHD Shapes

Cardinality = 0 or 1 to Many

NHDinSDEVersion 1.04a

04/07/2000

Added Relationship

Cardinality = 1

Duel Added Relationship

System File Reference


Events as Shapes

• Arc8 – seems to be moving away from dynamic segmentation

• Geodatabase options – might be able to use geodatabase tools to maintain spatial coincidence for reaches and shape events

• Display speed – shapes MUCH faster• Increased spatial selection options with

shapes


RAD Data Access

• Current Access– EnviroMapper– Tod Dabolt assigns you an ID

• Future; ArcIMS server– Allow data downloads– Hide some NHD complexity– Increase ease of external application use


Contact Information

• Steve Andrews• INDUS Corporation• [email protected]


NHD Application Data Access

• Where are the names?– Linear reaches– Area reaches (lake/pond)– Non-reachable features (gages, wells, etc.)– 2D reachable features - artificial path

• Waterbodies don’t correspond to reaches/artificial paths running through them

Documents

NHD Applications Symposium December 11-14,2000 - Austin, TX The National Hydrography Dataset: A Look at Database Structures Steve Andrews INDUS Corporation