Methods for querying the NHDPlus V2 data set. More...

Functions
def	getNHDReachcodeAndMeasureForGageSourceFea
	Get NHD Reachcode and measure along reach for a streamflow gage identified by a source_fea (e.g.

def	getLocationForStreamGageByGageSourceFea
	Get lat/lon, in WGS84 (EPSG:4326), from gage point layer (Gage_Loc) for gage identified by a source_fea (e.g.

def	getLocationForStreamGageByReachcodeAndMeasure
	Get lat/lon, in WGS84 (EPSG:4326), from gage point layer (Gage_Loc) for gage identified by reachcode and measure.

def	getLocationForStreamGage
	Get lat/lon, in WGS84 (EPSG:4326), from gage point layer (Gage_Loc) for gage identified by reachcode and measure.

def	getComIdForStreamGage
	Uses NHDFlowline and/or NHDReachCode_ComID table(s) to lookup the ComID associated with a stream gage identified by reach code and measure.

def	getPlusFlowPredecessors
	Get the immediate predecessors of the NHDPlus2 PlusFlow feature of comID.

def	getUpstreamReachesSQL
	Recursively searches PlusFlow table in an SQLite database for all stream reaches upstream of a given reach.

def	getBoundingBoxForCatchmentsForGage
	Get bounding box coordinates (in WGS 84) for the drainage area associated with a given NHD (National Hydrography Dataset) streamflow gage identified by a reach code and measure.

def	getCatchmentShapefileForGage
	Get shapefile (in WGS 84) for the drainage area associated with a given NHD (National Hydrography Dataset) streamflow gage identified by a reach code and measure.

def	getCatchmentShapefileForGageOGR
	Get shapefile (in WGS 84) for the drainage area associated with a given NHD (National Hydrography Dataset) streamflow gage identified by a reach code and measure.

Variables
int	NORTH 0

int	EAST 90

string	OGR_SHAPEFILE_DRIVER_NAME "ESRI Shapefile"

int	UPSTREAM_SEARCH_THRESHOLD 998

Detailed Description

Methods for querying the NHDPlus V2 data set.

Requires that a NHDPlus V2 database be initialized from data archive files using NHDPlusSetup.py

This software is provided free of charge under the New BSD License. Please see the following license information:

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

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Neither the name of the University of North Carolina at Chapel Hill nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Author: Brian Miles brian.nosp@m._mil.nosp@m.es@un.nosp@m.c.ed.nosp@m.u

Function Documentation

def ecohydroworkflowlib.nhdplus2.networkanalysis.getBoundingBoxForCatchmentsForGage	(	config,
		outputDir,
		reachcode,
		measure,
		deleteIntermediateFiles = `True`
	)

Get bounding box coordinates (in WGS 84) for the drainage area associated with a given NHD (National Hydrography Dataset) streamflow gage identified by a reach code and measure.

Parameters

config	A Python ConfigParser containing the following sections and options: 'GDAL/OGR' and option 'PATH_OF_OGR2OGR' (absolute path of ogr2ogr binary) 'NHDPLUS2' and option 'PATH_OF_NHDPLUS2_DB' (absolute path to SQLite3 DB of NHDFlow data) 'NHDPLUS2', 'PATH_OF_NHDPLUS2_CATCHMENT' (absolute path to NHD catchment SQLite3 spatial DB)
outputDir	String representing the absolute/relative path of the directory into which output rasters should be written
reachcode	String representing NHD streamflow gage
measure	Float representing the measure along reach where Stream Gage is located in percent from downstream end of the one or more NHDFlowline features that are assigned to the ReachCode (see NHDPlusV21 GageLoc table)
deleteIntermediateFiles	A boolean, True if intermediate files generated from the analysis should be deleted

Returns

A dictionary with keys: minX, minY, maxX, maxY, srs. The key srs is set to 'EPSG:4326' (WGS 84)

     @exception ConfigParser.NoSectionError
     @exception ConfigParser.NoOptionError
     @exception IOError(errno.ENOTDIR) if outputDir is not a directory
     @exception IOError(errno.EACCESS) if outputDir is not writable

def ecohydroworkflowlib.nhdplus2.networkanalysis.getCatchmentShapefileForGage	(	config,
		outputDir,
		catchmentFilename,
		reachcode,
		measure,
		deleteIntermediateFiles = `True`
	)

Get shapefile (in WGS 84) for the drainage area associated with a given NHD (National Hydrography Dataset) streamflow gage identified by a reach code and measure.

Note: Deprecated. Uses ogr2ogr binary and is limited to gages with <1000 upstream reaches. use getCatchmentShapefileForGageOGR instead; No return value. catchmentFilename will be written to outputDir if successful

Parameters

config	A Python ConfigParser containing the following sections and options: 'GDAL/OGR' and option 'PATH_OF_OGR2OGR' (absolute path of ogr2ogr binary) 'NHDPLUS2' and option 'PATH_OF_NHDPLUS2_DB' (absolute path to SQLite3 DB of NHDFlow data) 'NHDPLUS2', 'PATH_OF_NHDPLUS2_CATCHMENT' (absolute path to NHD catchment shapefile)
outputDir	String representing the absolute/relative path of the directory into which output rasters should be written
catchmentFilename	String representing name of file to save catchment shapefile to
reachcode	String representing NHD streamflow gage
measure	Float representing the measure along reach where Stream Gage is located in percent from downstream end of the one or more NHDFlowline features that are assigned to the ReachCode (see NHDPlusV21 GageLoc table)

Exceptions

ConfigParser.NoSectionError
ConfigParser.NoOptionError
IOError(errno.ENOTDIR)	if outputDir is not a directory
IOError(errno.EACCESS)	if outputDir is not writable
Exception	if number of upstream reaches is greater than 1000
Exception	of catchment shapefile extraction fails

def ecohydroworkflowlib.nhdplus2.networkanalysis.getCatchmentShapefileForGageOGR	(	config,
		outputDir,
		catchmentFilename,
		reachcode,
		measure,
		deleteIntermediateFiles = `True`
	)

Get shapefile (in WGS 84) for the drainage area associated with a given NHD (National Hydrography Dataset) streamflow gage identified by a reach code and measure.

Note: Capable of handling gages with more than 1000 upstream reaches; No return value. catchmentFilename will be written to outputDir if successful

Parameters

config	A Python ConfigParser containing the following sections and options: 'NHDPLUS2' and option 'PATH_OF_NHDPLUS2_DB' (absolute path to SQLite3 DB of NHDFlow data) 'NHDPLUS2', 'PATH_OF_NHDPLUS2_CATCHMENT' (absolute path to NHD catchment shapefile)
outputDir	String representing the absolute/relative path of the directory into which output rasters should be written
catchmentFilename	String representing name of file to save catchment shapefile to
reachcode	String representing NHD streamflow gage
measure	Float representing the measure along reach where Stream Gage is located in percent from downstream end of the one or more NHDFlowline features that are assigned to the ReachCode (see NHDPlusV21 GageLoc table)

Exceptions

ConfigParser.NoSectionError
ConfigParser.NoOptionError
IOError(errno.ENOTDIR)	if outputDir is not a directory
IOError(errno.EACCESS)	if outputDir is not writable

def ecohydroworkflowlib.nhdplus2.networkanalysis.getComIdForStreamGage	(	conn,
		reachcode,
		measure
	)

Uses NHDFlowline and/or NHDReachCode_ComID table(s) to lookup the ComID associated with a stream gage identified by reach code and measure.

Parameters

conn	An sqlite3 connection to a database that has the NHDFlowline and NHDReachCode_Comid tables
reachcode	An string representing the Reachcode #param measure A float representing the measure along reach where Stream Gage is located in percent from downstream end of the one or more NHDFlowline features that are assigned to the ReachCode (see NHDPlusV21 GageLoc table)

Returns: An integer representing the ComID associated with a Reachcode, or -1 if a reach with Reachcode was not found.

def ecohydroworkflowlib.nhdplus2.networkanalysis.getLocationForStreamGage	(	config,
		whereFilter
	)

Get lat/lon, in WGS84 (EPSG:4326), from gage point layer (Gage_Loc) for gage identified by reachcode and measure.

Parameters

config	A Python ConfigParser containing the following sections and options: 'NHDPLUS2', 'PATH_OF_NHDPLUS2_GAGELOC' (absolute path to NHD GageLoc SQLite3 spatial database)
whereFilter	String representing the whereFilter to use

Returns

A tuple with (x,y) coordinates in 'EPSG:4326' (WGS 84); None if gage was not found

     @exception ConfigParser.NoSectionError
     @exception ConfigParser.NoOptionError
     @exception IOError(errno.ENOTDIR) if GageLoc is not readable

def ecohydroworkflowlib.nhdplus2.networkanalysis.getLocationForStreamGageByGageSourceFea	(	config,
		source_fea
	)

Get lat/lon, in WGS84 (EPSG:4326), from gage point layer (Gage_Loc) for gage identified by a source_fea (e.g.

USGS Site Number)

Parameters

config	A Python ConfigParser containing the following sections and options: 'NHDPLUS2', 'PATH_OF_NHDPLUS2_GAGELOC' (absolute path to NHD GageLoc SQLite3 spatial database)
source_fea	String representing source_fea of GageLoc gage

Returns: A tuple with (x,y) coordinates in 'EPSG:4326' (WGS 84)

def ecohydroworkflowlib.nhdplus2.networkanalysis.getLocationForStreamGageByReachcodeAndMeasure	(	config,
		reachcode,
		measure
	)

Get lat/lon, in WGS84 (EPSG:4326), from gage point layer (Gage_Loc) for gage identified by reachcode and measure.

Parameters

config	A Python ConfigParser containing the following sections and options: 'NHDPLUS2', 'PATH_OF_NHDPLUS2_GAGELOC' (absolute path to NHD GageLoc SQLite3 spatial database)
reachcode	String representing NHD streamflow gage
measure	Float representing the measure along reach where Stream Gage is located in percent from downstream end of the one or more NHDFlowline features that are assigned to the ReachCode (see NHDPlusV21 GageLoc table)

Returns: A tuple with (x,y) coordinates in 'EPSG:4326' (WGS 84); None if gage was not found

def ecohydroworkflowlib.nhdplus2.networkanalysis.getNHDReachcodeAndMeasureForGageSourceFea	(	config,
		source_fea
	)

Get NHD Reachcode and measure along reach for a streamflow gage identified by a source_fea (e.g.

USGS Site Number)

Parameters

config	A Python ConfigParser containing the following sections and options: 'NHDPLUS2', 'PATH_OF_NHDPLUS2_DB' (absolute path to NHDPlus2 SQLite3 database)
source_fea	String representing source_fea of GageLoc gage

Returns

A tuple(string, float) representing the reachcode and measure; None if no gage was found.

     @exception ConfigParser.NoSectionError
     @exception ConfigParser.NoOptionError
     @exception IOError(errno.EACCES) if NHDPlus2 DB is not readable

def ecohydroworkflowlib.nhdplus2.networkanalysis.getPlusFlowPredecessors	(	conn,
		comID
	)

Get the immediate predecessors of the NHDPlus2 PlusFlow feature of comID.

Parameters

conn	A connection an SQLite3 database
comdID	String representing the ComID of the reach whose immediate predecessor reaches are to be discovered

Returns: A list of immediate predecessor nodes in the NHDPlus2 PlusFlow graph

def ecohydroworkflowlib.nhdplus2.networkanalysis.getUpstreamReachesSQL	(	conn,
		comID,
		allUpstreamReaches
	)

Recursively searches PlusFlow table in an SQLite database for all stream reaches upstream of a given reach.

Note: This method has no return value. Upstream reaches discovered are appended to allUpstreamReaches list.

Parameters

conn	A connection to an SQLite3 database
comID	The ComID of the reach whose upstream reaches are to be discovered
allUpstreamReaches	A list containing integers representing comIDs of upstream reaches

Variable Documentation

int ecohydroworkflowlib.nhdplus2.networkanalysis.EAST 90

int ecohydroworkflowlib.nhdplus2.networkanalysis.NORTH 0

string ecohydroworkflowlib.nhdplus2.networkanalysis.OGR_SHAPEFILE_DRIVER_NAME "ESRI Shapefile"

int ecohydroworkflowlib.nhdplus2.networkanalysis.UPSTREAM_SEARCH_THRESHOLD 998

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation