Archydro manual

ArcGIS Hydro Data Model

ArcGIS Hydro Data Model
(Draft, July 2001)

This document provides an overview of the ArcGIS Hydro Data Model. This model contains geospatial and temporal data describing the surface water flow system of the landscape.

ArcGIS Data Models

THIS DOCUMENT IS PART OF A BOOK TO BE PUBLISHED BY ESRI DESCRIBING THE ARCGIS HYDRO DATA MODEL. THE TEXT GIVEN HERE MAY BEALTERED DURING THE BOOK PRODUCTION PROCESS. MATERIAL WILL BE ADDED TO THAT SHOWN HERE TO DESCRIBE HOW TO APPLY AND CUSTOMIZE THE DATA MODEL.

2 • ArcGIS Hydro Data Model

INTRODUCTION
The ArcGIS Hydro data model describes geospatial and temporal data on surface water resource features of the landscape. The data model addresses three issues: • • • Hydro Description – What are the principalwater resource features of the landscape? Hydro Connectivity – How does water move from feature to feature? Hydro Modeling – What are the time patterns of water flow and water quality associated with these features?

The ArcGIS Hydro data model describes only natural water systems, and does not support constructed water infrastructure, for which there is a separate data model, ArcFM Water.Moreover, features describing aquatic ecology, geomorphology, and groundwater systems are not currently supported by the model. The title ArcGIS Hydro data model, is often shortened in this description to Arc Hydro, but the two titles for the data model are synonymous. An Arc Hydro geodatabase consists of Hydro Features connected to Time Series. Hydro Features describe the physical environment throughwhich water flows, and the Time Series describe the flow and water quality properties of the water within those features. Every Hydro Feature is uniquely defined within an Arc Hydro geodatabase by a HydroID, and associations are formed between features by storing the HydroID of one feature as an attribute of another. These linkages can be used to trace water movement from one feature to the next, andalso to associate several different geospatial representations of the same hydrologic entity with one another. Time series are connected to Hydro Features by storing the HydroID of the feature as an attribute of each time series data value. The Arc Hydro data model consists of five components: Network, Drainage, Channels, Hydrography and Time Series: • The Network component contains a waterresources network of streams, rivers and the centerlines of water bodies. Its main purpose is to describe the connectivity of water movement through the landscape • The Drainage component defines drainage areas delineated through analysis of land surface topography • The Channel component describes the three-dimensional shape of river and stream channels • The Hydrography component contains base mapinformation on point, line and area water resource features • The Time Series component describes time varying water properties of the features. A more detailed view of all the feature and object classes in the Arc Hydro model is contained in the following analysis diagram. Each feature and object class in the analysis diagram is described in this book.

ArcGIS Hydro Data Model • 3

Componentsof the Arc Hydro data model
HydroFeature
Hy droID Hy droC ode

SimpleJunctionFeature

ComplexEdgeFeature

1
DrainageFeature
DrainID

HydroJunction
Hy droID Hy droC ode NextD ow nID LengthDown DrainA rea F Ty pe Enabled A ncillary Role

HydroEdge
Hy droID Hy droC ode ReachC ode Name LengthKm LengthDown F low Dir F Ty pe Edge Ty pe Enabled

1

Object

DrainagePoint
JunctionIDDrainageArea
A reaSqKm JunctionID N extDownID

DrainageLine

HydroFeature
H y droID H y droC ode

HydroEvent
Re achC ode

EdgeType Flowline Shoreline

Cat chment

Watershed

Basin

SchematicNode
F eatureID

SchematicLink
F romN ode T oNode

HydroPoint Event
M easure

HydroLineEvent
F M easure TM easure O ffset

Drainage
Feature

1

Network
HydroFeature
H...