HYDRO TRACE

♦ This tool requires Network Analyst.

Summary

Hydro Trace utilizes NHDPlus High Resolution (HR) hydrography data to trace the downstream progress of a liquid release plume from the point where it first encounters a waterway.

To learn more about the Liquids HCA Tool in general, please see Liquids HCA Tool Frequently Asked Questions.

To learn more about the structure of the Liquids HCA Tool project geodatabase, please see Liquids HCA Tool Data Dictionary.

Usage

Hydro Trace uses the NHD intersection point features output by the Calculate Land Spill NHD Intersections tool as the starting points for hydrographic release plume transport simulations. Three NHD feature types downloaded by the NHDPlus High Resolution Data Download tool are used directly in release plume hydrographic transport simulations:

• Flowlines – NHD flowline features are polyline features that represent the flowing river/stream network in the NHDPlus HR dataset. They primarily comprise smaller rivers and streams that can be represented with simple polylines, as well as artificial paths delineating the flow network through larger rivers (and other hydrographic features where flow is present) represented by NHD area polygons.
• Waterbodies – NHD waterbodies comprise the polygonal representations of nominally non-flowing waterbodies, such as lakes, ponds, and reservoirs. For the sake of hydrographic network continuity, many of these nominally non-flowing waterbody features are accompanied by corresponding artificial paths in the NHD flowlines feature class that define the nominal flow network through these non-flowing waterbody features.
• Areas – NHD areas primarily comprise the polygonal representations of larger (wider) rivers and other flowing bodies of water. Corresponding artificial paths in the NHD flowlines dataset define the flow network through the NHD area features. NHD area features also include areal features that are only intermittently wetted, such as foreshore areas, inundation areas, flumes, spillways, and washes, as well as miscellaneous features, such as submerged rivers, bridges, levees, lock chambers, and dams/weirs. Also represented as NHD areas are marine features, such as bays/inlets and sea/ocean areas. NHD area features other than those corresponding to rivers may or may not be accompanied by artificial paths in the NHD flowline features.

For cases in which the NHD intersection point impinges on an NHD flowline feature, Hydro Trace initializes the downstream trace of the release plume through the NHDPlus HR stream network using the NHDPlus HR hydrography Network Dataset generated by the NHDPlus High Resolution Data Download tool. Hydro Trace treats the downstream trace computation as an Esri Network Analyst service area analysis problem. (For complex flow analyses of the sort performed by Hydro Trace, Esri Network Analyst technology offers far more scalable performance than that offered by Esri Geometric Network or Trace Network technology.) The assigned stream velocity for flowlines is the second positive deviation value of the monthly flowline stream velocities, or VEMA (NHD adjusted stream velocity), whichever is higher. The features resulting from this downstream NHD stream network trace are polylines.

During the downstream trace, the release plume may encounter either NHD waterbody or NHD area features. The tool processes large and small NHD waterbodies differently. (You set the size threshold for large/small NHD waterbodies per centerline route feature when you ran either Enter Global Input Data or Import Global Input Data; the default threshold size value is 10 acres.) Processing behavior for NHD waterbody and area features also varies depending on whether these features contain associated NHD artificial path flowline features. NHD artificial path flowline features are used to route the NHD stream network through NHD waterbody and area features and may or may not be present depending on NHD waterbody/area feature type and size.

For small NHD waterbody features and NHD area features (of any size) where associated NHD flowline artificial path features are present, the software assumes that flow is through the NHD waterbody/area feature, and the downstream trace proceeds apace via the hydrography network. (Appropriate slick and shoreline losses are calculated for small NHD waterbody features.) For artificial path flowlines through small NHD waterbodies (where water velocities are assumed to be low, but non-zero), the assigned stream velocity is the second negative deviation value of the monthly flowline stream velocities, or VEMA, whichever is lower. (NHD area features that have associated artificial path flow line features generally represent large/wide rivers, and so are treated like regular NHD flowline features for stream velocity assignment.)

When large NHD waterbody features are encountered in the downstream NHD stream network trace, the software assumes that the plume will spread into the NHD waterbody feature, and the software enters radial spread mode, which models plume slick spread under windless conditions. The features resulting from radial spread mode are polygons. Radial spread polygon growth rate is constrained by conservation of mass and is thus governed by slick thickness, area, pumping/gravity drain rate, and remaining plume volume. (You set slick thickness values for large and small NHD waterbodies on a per centerline route basis when you ran either Enter Global Input Data or Import Global Input Data.) Artificial path flowline features within large NHD waterbodies are ignored even if they are intersected by the radial spread polygon. However, should the radial spread polygon subsequently encounter an NHD flowline feature along the edge of the NHD waterbody feature that is flowing away from the NHD waterbody, the downstream NHD stream network trace resumes. Similarly, should an NHD area feature lacking associated artificial path flow line features be encountered in the downstream NHD stream network trace, the software likewise enters radial spread mode. If the radial spread polygon subsequently encounters an NHD flowline feature along the edge of the NHD area feature that is flowing away from the NHD area feature, the downstream NHD stream network trace again resumes. For a given NHD intersection point, hydrographic transport simulation may transition between downstream trace and radial spread multiple times.

In cases where the NHD intersection point impinges on a small NHD waterbody or an NHD area feature, Hydro Trace initializes in radial spread mode. If the radial spread polygon encounters an NHD artificial path flowline feature within the NHD waterbody/area feature, or an NHD flowline feature along the edge of the NHD waterbody/area feature flowing away from the NHD waterbody/area, the tool initiates a downstream NHD stream network trace.

In cases where the NHD intersection point impinges on a large NHD waterbody feature, Hydro Trace initializes in radial spread mode. If the radial spread polygon encounters an NHD flowline feature along the edge of the NHD waterbody feature flowing away from the NHD waterbody, the tool initiates a downstream NHD stream network trace. Artificial path flowline features within large NHD waterbodies are ignored even if they are intersected by the radial spread polygon.

Hydro Trace uses the following parameters:

• Input Project Database – This is the project file geodatabase you created with the Initialize Database tool. By default, your input NHD intersection points, global inputs table, and NHDPlus HR hydrography network features are sourced from your project file geodatabase, and the derived output trace path and waterbody spread polygon feature classes are written to your project file geodatabase.
• Input Land Spill NHD Intersection Point Features – This parameter is the feature layer containing the NHD intersection point features you previously created using the Calculate Land Spill NHD Intersections tool. These point features represent the spatial location at which a given overland plume first intersects a given NHDPlus HR feature. Your input Land Spill NHD intersection points thus define the starting points for your release plume hydrographic transport simulations.
• Global Inputs Table – This parameter is the table or table view that stores product properties and operating and ambient conditions data for the centerline route features associated with your release plumes. You populated the global inputs table using either the Import Global Input Data tool or Enter Global Input Data tool.
• Output Hydro Transport Paths Feature Class – This parameter allows you to specify the name and location of the output hydrographic trace path results polyline feature class. The default value is HydrographicTransportPaths, located by default in your specified input project file geodatabase. There is generally no need to alter the default value.
• Output Waterbody Spread Polygons Feature Class – This parameter allows you to specify the name and location of the output hydrographic transport slick radial spread results polygon feature class. The default value is WaterbodySpreadPolygons, located by default in your specified input project file geodatabase. There is generally no need to alter the default value.
• Land Spill NHD Intersection Points Field Parameters – This parameter group collects a set of derived field parameters for your input NHD intersection point features. Hydro Trace automatically searches for these fields in the NHD intersection points feature layer, so there is generally no reason to alter any of these parameters. Hydro Trace makes use of the following fields from NHD intersection points feature layer:
  • Point Identifier Field – This parameter is the field that uniquely identifies each release point. The default value is the POINT_ID field in the NHD intersection points feature layer. There is generally no need to alter the default value.
  • Route Identifier Field – This parameter is the field that identifies the route on which the release point for the release plume lies. The default value is the ROUTE_ID field in the NHD intersection points feature layer. There is generally no need to alter the default value.
  • NHD Type Field – This parameter is the field in the NHD intersection points feature layer that identifies the type of NHDPlus HR hydrography feature intersected by the overland plume. Possible values are NHDFlowline, NHDArea, or NHDWaterbody. The default value is the NHD_TYPE field in the NHD intersection points feature layer. There is generally no need to alter the default value.
  • NHD Identifier Field – This parameter is the field in the NHD intersection points feature layer that uniquely identifies the intersected NHDPlus HR feature. The default value is the NHD_ID field in the NHD intersection points feature layer. There is generally no need to alter the default value.
  • Land Spill Intersection Time Field – This parameter is the field in the NHD intersection points feature layer that stores the elapsed time from the beginning of the release (in minutes) at which the overland plume intersects the NHDPlus HR feature. The default value is the TIME_IN field in the NHD intersection points feature layer. There is generally no need to alter the default value.
  • Remaining Simulation Time Field – This parameter is the field in the NHD intersection points feature layer that stores the time remaining (in minutes) in the simulation (the time remaining until the hydrographic transport response time is met). The default value is the REM_TIME field in the NHD intersection points feature layer. There is generally no need to alter the default value.
  • Remaining Volume Field – This parameter is the field in the NHD intersection points feature layer that stores the remaining plume product volume (in petroleum barrels) at the time at which the overland plume intersects the NHDPlus HR feature. The downstream trace algorithm assumes (conservatively) that the entire remaining plume volume is introduced into the NHDPlus HR feature. The default value is the REM_VOL field in the NHD intersection points feature layer. There is generally no need to alter the default value.
  • Drain Volume Field – This parameter is the field in the NHD intersection points feature layer that stores the total release point drain volume (in petroleum barrels). It is used in the calculation of evaporation loss. The default value is the DRAIN_VOL field in the NHD intersection points feature layer. There is generally no need to alter the default value.
  • Drain Rate Field – This parameter is the field in the NHD intersection points feature layer that stores the release point drain rate (in petroleum barrels/hour). The value stored in the field is the maximum gravity drain rate. The default value is the DRAIN_RATE field in the NHD intersection points feature layer. There is generally no need to alter the default value.
  • Hydrographic Transport Response Time Field – This parameter is the field in the NHD intersection points feature layer that stores the hydrographic transport response time (in minutes). Hydrographic response time is the time it takes your response crew to contain the release plume (via boom/skimmer emplacement, etc.). The default value is the HTRES_TIME field in the NHD intersection points feature layer. There is generally no need to alter the default value.
  • Intersection Distance Field – This parameter is the field in the NHD intersection points feature layer that stores the distance between the release point and the NHD intersection point (in meters, as-the-crow-flies). The default value is the DIST_IN field in the NHD intersection points feature layer. There is generally no need to alter the default value.
• Global Inputs Table Field Parameters – This parameter group collects a set of derived field parameters for your input global inputs table. Hydro Trace automatically searches for these fields in the global inputs table, so there is generally no reason to alter any of these parameters. Hydro Trace makes use of the following fields from the global inputs table:
  • Global Inputs Route Identifier Field – This parameter is the field that identifies the route on which the release point for the release plume lies. The default value is the ROUTE_ID field in the global inputs table. There is generally no need to alter the default value.
  • Evaporation Equation Type Field – This parameter is the field that stores the evaporation equation type. Valid values are ‘Fingas’ or ‘G2-IS.’ The default value is the EQ_TYPE field in the global inputs table. There is generally no need to alter the default value.
  • Evaporation Equation Form Field – This parameter is the field that stores the evaporation equation form. Valid values are ‘Logarithmic’ or ‘Square Root.’ The default value is the EQ_FORM field in the global inputs table. There is generally no need to alter the default value.
  • Evaporation Coefficient 1 Field – This parameter is the field that stores the evaporation equation coefficient 1 for the product for the centerline route from which the product plume is released. The default value is the FINGAS_1 field in the global inputs table. There is generally no need to alter the default value.
  • Evaporation Coefficient 2 Field – This parameter is the field that stores the evaporation equation coefficient 1 for the product for the centerline route from which the product plume is released. The default value is the FINGAS_2 field in the global inputs table. There is generally no need to alter the default value.
  • Ambient Temperature Field – This parameter is the field that stores ambient temperature for the release plume (in degrees C). The default value is the T_AMB field in the global inputs table. There is generally no need to alter the default value.
  • Wind Velocity Field – This parameter is the field that stores ambient wind velocity (in m/s). The default value is the WIND_VEL field in the global inputs table. There is generally no need to alter the default value.
  • Small Waterbody Depth Field – This parameter is the field that stores nominal water depth for small NHDPlus HR waterbody features. The default value is the DEPTH_H2O field in the global inputs table. There is generally no need to alter the default value.
  • Small Waterbody Product Adhesion Rate Field – This parameter is the field that stores the shoreline product adhesion rate for small NHDPlus HR waterbody features (in g/m²). The default value is the WB_ADHSN field in the global inputs table. There is generally no need to alter the default value.
  • Small Waterbody Bank Angle Field – This parameter is the field that stores the nominal bank slope angle (in degrees) for small NHDPlus HR waterbody features. The default value is the BANK_ANGL field in the global inputs table. There is generally no need to alter the default value.
  • Small Waterbody Slick Thickness Field – This parameter is the field that stores nominal product slick thickness (in m) for small NHDPlus HR waterbody features. The default value is the SLKTHKSMWB field in the global inputs table. There is generally no need to alter the default value.
  • Large Waterbody Slick Thickness Field – This parameter is the field that stores nominal product slick thickness (in m) for large NHDPlus HR waterbody features. The default value is the SLICK_THK field in the global inputs table. There is generally no need to alter the default value.
  • Product API Gravity Field – This parameter is the field that stores product API gravity (in degrees API) for the release plume. The default value is the API_GRAV field in the global inputs table. There is generally no need to alter the default value.
  • Product Density Field – This parameter is the field that stores product density (in g/cc) for the release plume. The default value is the PROD_DNSTY field in the global inputs table. There is generally no need to alter the default value.
  • Pumping Rate Field – This parameter is the field that stores the pumping flow rate (in bbl/hr) for the centerline route from which the product plume is released. The default value is the FLOW_RATE field in the global inputs table. There is generally no need to alter the default value.
  • Pipeline Shutdown Time Field – This parameter is the field that stores the pipeline shutdown time (in minutes) for the centerline route from which the product plume is released. The default value is the P_SD_TIME field in the global inputs table. There is generally no need to alter the default value.
• NHDPlus HR Input Parameters – This parameter group allows you to specify the NHDPlus HR data elements used by the tool. You previously generated the NHDPlus HR data layers in your project file geodatabase using the NHDPlus High Resolution Data Download tool. The following NHDPlus HR feature layers and data attributes are required:
  • Input NHD Flowline Features – This parameter allows you to select the NHDPlus HR flowline features for use by Hydro Trace. Hydro Trace automatically searches for the NHDFlowline feature class in your project file geodatabase; this is the default value. There is generally no need to alter the default value.
  • NHD Flowline Stream Velocity Field – This parameter allows you to select the field that stores stream velocity in the NHD flowlines feature layer. The default value is the STREAM_VEL field in your specified NHD flowlines feature layer. There is generally no need to alter the default value.
  • Input NHD Area Features – This parameter allows you to select the NHDPlus HR area features for use by Hydro Trace. Hydro Trace automatically searches for the NHDArea feature class in your project file geodatabase; this is the default value. There is generally no need to alter the default value.
  • Input NHD Waterbody Features – This parameter allows you to select the NHDPlus HR waterbody features for use by Hydro Trace. Hydro Trace automatically searches for the NHDWaterbody feature class in your project file geodatabase; this is the default value. There is generally no need to alter the default value.

For more information on the NHDPlus HR dataset, see the USGS publication, User’s Guide for the National Hydrography Dataset Plus (NHDPlus) High Resolution.

In a typical Liquids HCA Tool workflow, you run Hydro Trace after Calculate Land Spill NHD Intersections and before Calculate Hydro Trace HCA Intersections.

For visual reference on Liquids HCA Tool execution order, see Liquids HCA Tool Process Flow Diagrams.

Syntax

HydroTrace_ (in_workspace, in_nhd_intersections_features, in_global_inputs_table, in_htpath_name, in_waterbodyspread_name, in_nhdint_pointid_field, in_nhdint_routeid_field, in_nhdint_nhdtype_field, in_nhdint_nhdid_field, in_nhdint_timein_field, in_nhdint_remtime_field, in_nhdint_remvol_field, in_nhdint_drainvol_field, in_nhdint_drainrate_field, in_nhdint_htrestime_field, in_nhdint_distin_field, in_gi_routeid_field, in_gi_eqtype_field, in_gi_eqfrom_field, in_gi_eqco1_field, in_gi_eqco2_field, in_gi_tamb_field, in_gi_windvel_field, in_gi_depthh2o_field, in_gi_wbadhsn_field, in_gi_bnkangl_field, in_gi_slickthksm_field,  in_gi_slickthk_field, in_gi_apigrav_field, in_gi_proddnsty_field, in_gi_flowrate_field, in_gi_psdtime_field, in_nhd_flowline_features, in_nhd_flowline_stream_vel_field, in_nhd_area_features, in_nhd_waterbody_features)

Parameter	Explanation	Data Type
in_workspace	Dialog Reference Specify the input liquids HCA project geodatabase. There is no Python reference for this parameter.	Workspace
in_nhd_intersections_features	Dialog Reference Select the NHD intersection features from your input project geodatabase. There is no Python reference for this parameter.	Feature Layer
in_global_inputs_table	Dialog Reference Select the global inputs table from your input project geodatabase. There is no Python reference for this parameter.	Table View
in_htpath_name	Dialog Reference Specify the name and location of the output hydrographic trace path results polyline feature class. There is no Python reference for this parameter.	String
in_waterbodyspread_name	Dialog Reference Specify the name and location of the output hydrographic transport slick radial spread results polygon feature class. There is no Python reference for this parameter.	String
in_nhdint_pointid_field	Dialog Reference Select the field in the input NHD intersection points feature layer that uniquely identifies the release point features associated with the release plumes. There is no Python reference for this parameter.	Field
in_nhdint_routeid_field	Dialog Reference Select the field in the input NHD intersection points feature layer that uniquely identifies the centerline route features associated with the release plumes. There is no Python reference for this parameter.	Field
in_nhdint_nhdtype_field	Dialog Reference Select the field in the input NHD intersection points feature layer that indicates the type of NHDPlus HR feature intersected by the release plume. There is no Python reference for this parameter.	Field
in_nhdint_nhdid_field	Dialog Reference Select the field in the input NHD intersection points feature layer that uniquely identifies the intersected NHDPlus HR feature. There is no Python reference for this parameter.	Field
in_nhdint_timein_field	Dialog Reference Select the field in the input NHD intersection points feature layer that stores the elapsed time from the beginning of the release to the point of intersection with the NHDPlus HR feature. There is no Python reference for this parameter.	Field
in_nhdint_remtime_field	Dialog Reference Select the field in the input NHD intersection points feature layer that stores the time remaining in the simulation. There is no Python reference for this parameter.	Field
in_nhdint_remvol_field	Dialog Reference Select the field in the input NHD intersection points feature layer that stores the remaining release plume volume. There is no Python reference for this parameter.	Field
in_nhdint_drainvol_field	Dialog Reference Select the field in the input NHD intersection points feature layer that stores the total drain volume for the release plume. There is no Python reference for this parameter.	Field
in_nhdint_drainrate_field	Dialog Reference Select the field in the input NHD intersection points feature layer that stores the maximum gravity drain rate for the release. There is no Python reference for this parameter.	Field
in_nhdint_htrestime_field	Dialog Reference Select the field in the input NHD intersection points feature layer that stores the hydrographic transport response time. There is no Python reference for this parameter.	Field
in_nhdint_distin_field	Dialog Reference Select the field in the input NHD intersection points feature layer that stores the distance between the release point and the NHDPlus HR feature intersection point. There is no Python reference for this parameter.	Field
in_gi_routeid_field	Dialog Reference Select the field in the input global inputs table that uniquely identifies each input centerline route feature. There is no Python reference for this parameter.	Field
in_gi_eqtype_field	Dialog Reference Select the field in the input global inputs table that stores the evaporation equation type. There is no Python reference for this parameter.	Field
in_gi_eqfrom_field	Dialog Reference Select the field in the input global inputs table that store the evaporation equation form. There is no Python reference for this parameter.	Field
in_gi_eqco1_field	Dialog Reference Select the field in the input global inputs table that stores evaporation equation coefficient 1. There is no Python reference for this parameter.	Field
in_gi_eqco2_field	Dialog Reference Select the field in the input global inputs table that stores evaporation equation coefficient 2. There is no Python reference for this parameter.	Field
in_gi_tamb_field	Dialog Reference Select the field in the input global inputs table that stores ambient temperature for the simulation. There is no Python reference for this parameter.	Field
in_gi_windvel_field	Dialog Reference Select the field in the input global inputs table that stores ambient wind velocity for the simulation. There is no Python reference for this parameter.	Field
in_gi_depthh2o_field	Dialog Reference Select the field in the input global inputs table that stores small NHDPlus HR nominal waterbody depth. There is no Python reference for this parameter.	Field
in_gi_wbadhsn_field	Dialog Reference Select the field in the input global inputs table that stores the small NHDPlus HR waterbody shoreline product adhesion rate. There is no Python reference for this parameter.	Field
in_gi_bnkangl_field	Dialog Reference Select the field in the input global inputs table that stores the small NHDPlus HR waterbody nominal bank inclination angle. There is no Python reference for this parameter.	Field
in_gi_slickthksm_field	Dialog Reference Select the field in the input global inputs table that stores the small NHDPlus HR waterbody slick thickness value. There is no Python reference for this parameter.	Field
in_gi_slickthk_field	Dialog Reference Select the field in the input global inputs table that stores the large NHDPlus HR waterbody slick thickness value. There is no Python reference for this parameter.	Field
in_gi_apigrav_field	Dialog Reference Select the field in the input global inputs table that stores product API gravity. There is no Python reference for this parameter.	Field
in_gi_proddnsty_field	Dialog Reference Select the field in the input global inputs table that stores product density. There is no Python reference for this parameter.	Field
in_gi_flowrate_field	Dialog Reference Select the field in the input global inputs table that stores the pipeline pumping flow rate for the release. There is no Python reference for this parameter.	Field
in_gi_psdtime_field	Dialog Reference Select the field in the input global inputs table that stores the time required to shut down the pipeline following a release. There is no Python reference for this parameter.	Field
in_nhd_flowline_features	Dialog Reference Select the input NHDPlus HR flowline features from your input project geodatabase. There is no Python reference for this parameter.	Feature Layer
in_nhd_flowline_stream_vel_field	Dialog Reference Select the field in your input NHDPlus HR flowline features that stores stream velocity. There is no Python reference for this parameter.	Field
in_nhd_area_features	Dialog Reference Select the input NHDPlus HR area features from your input project geodatabase. There is no Python reference for this parameter.	Feature Layer
in_nhd_waterbody_features	Dialog Reference Select the input NHDPlus HR waterbody features from your input project geodatabase. There is no Python reference for this parameter.	Feature Layer

Code sample

The following script demonstrates how to use Hydro Trace to perform land spill intersections with waterways. The output of this tool will contain the trace path and spread polygons features:

Environments

Current Workspace, Scratch Workspace, Default Output Z Value, M Resolution, M Tolerance, Output M Domain, Output XY Domain, Output Z Domain, Output Coordinate System, Geographic Transformations, Output has M values, Output has Z values, XY Resolution, XY Tolerance, Z Resolution, Z Tolerance

Licensing information

This tool requires a valid Liquids HCA Tool user license or subscription. Please see the Request License and Register License tool help topics for details on obtaining and registering a Liquids HCA Tool software license.

This tool requires an Esri Network Analyst license.

Related topics

• An overview of the Liquids HCA Tool toolbox
• An overview of the Global Inputs table
• Initialize Database
• Enter Global Input Data
• Import Global Input Data
• NHDPlus High Resolution Data Download
• Calculate Land Spill HCA Intersections
• Calculate Hydro Trace HCA Intersections

Tags

Liquids HCA, NHD, NHDPlus HR, Hydro Trace.

Credits

Copyright © 2003-2020 by G2 Integrated Solutions, LLC. All Rights Reserved.

Use limitations

There are no access and use limitations for this item.