Thin Hydro Features (Production Mapping)
Summary
Generalizes input hydrographic stream data into two feature classes: one for hydro polyline features and one for hydro polygon features. The generalized versions are produced using a stream order algorithm. The algorithm removes less significant hydro features based on the number of tributaries.
The following is a sample of a stream network before and after using the Thin Hydro Features geoprocessing tool:
Illustration
Usage
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Input Hydro Features must be polyline or polygon features.
The direction in which polylines in Input Hydro Features are digitized should be the same as flow direction.
Polylines in Input Hydro Features should be split at intersections to ensure correct order value assignment.
Input Hydro Features must reside within a feature dataset. This tool will display a validation error if you add a feature class that does not belong to a feature dataset.
All feature classes listed in Input Hydro Features must originate from the same feature dataset. This tool will display a validation error if feature classes listed in Input Hydro Features originate from different feature datasets.
This tool will add a LONG field called ORD to the Output Hydro Line Feature Class and Output Hydro Polygon Feature Class. The ORD field contains stream order values for each input hydro feature.
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The Input Area of Interest Features parameter defines map extents.
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You can apply a selection set or definition query to Input Area of Interest Features, but not to Input Hydro Features.
Syntax
| Parameter | Explanation | Data Type |
in_hydro_features [in_hydro_features,...] |
The input hydro feature class or feature layer that contains the hydrographic features to be thinned. | Feature Layer |
out_hydro_line_feature_class |
The new or existing output hydro line feature class that contains the hydro line features after the thinning process. When an existing feature class is used, thinning will overwrite the existing hydro line features in the feature class. | Feature Class |
out_hydro_polygon_feature_class |
The new or existing output hydro polygon feature class that contains the hydro polygon features after the thinning process. When an existing feature class is used, thinning will overwrite the existing hydro polygon features in the feature class. | Feature Class |
in_min_hydro_order (Optional) | The minimum hydro order or stream order value used to eliminate hydro features. The tool will thin hydro features that have a stream order value less than this number. The tool will write stream order values to an ORD field in Output Hydro Line Feature Class and Output Hydro Polygon Feature Class. | Long |
in_min_feature_size (Optional) |
The minimum area used in the thinning algorithm to eliminate small, non-main hydro polygons. Units default to the input data unit of measurement. | Double |
in_aoi_features (Optional) |
The optional area of interest (AOI) feature class that is used to clip input hydro features. The thinning algorithm is executed on each extent of the AOI feature and the results are written to the output hydro line and polygon feature classes. | Feature Layer |
aoi_field (Optional) | The field that contains a unique identifier for each feature in Input Area of Interest Features . | Field |
Code Sample
The following ArcGIS Python window script uses the ThinHydroFeatures function to generalize sample data released with Esri Production Mapping.
import arcpy
# use the WatrcrsL feature class from production mapping sample data
WatrcrsL = "C:\\data\\Foundation_Data_Tutorials\\MPS-Atlas\\GDB\\SoCal.gdb\\SoCal\\WatrcrsL"
WatrcrsL_Layer = "WatrcrsL_Layer"
# these are the output feature classes
WatrcrsL_HydroLine = "C:\\data\\work.gdb\\WatrcrsL_HydroLine"
WatrcrsL_HydroPolygon = "C:\\data\\work.gdb\\WatrcrsL_HydroPolygon"
# import the production mapping toolbox
arcpy.ImportToolbox(r'C:\Program Files\ArcGIS\Desktop10.0\ArcToolbox\Toolboxes\Production Mapping Tools.tbx')
# Make Feature Layer from the watrcrsl feature class
arcpy.MakeFeatureLayer_management(WatrcrsL, WatrcrsL_Layer)
# Exec Thin Hydro Features
arcpy.ThinHydroFeatures_production("WatrcrsL_Layer", WatrcrsL_HydroLine, WatrcrsL_HydroPolygon, "0", "0", "", "")