Basin_sa (in_flow_direction_raster, out_raster)

Parameter	Explanation	Datatype
Input flow direction raster (Required)	The input raster that shows the direction of flow out of each cell. This is created with the Flow Direction function.	Composite Geodataset
Output raster (Required)	The output raster that delineates the drainage basins.	Raster Dataset

Data types for geoprocessing tool parameters

Script Example

# Basin_sample.py
# Description: 
#   Creates a raster delineating all drainage basins.
# Requirements: None
# Author: ESRI
# Date: Sept 6, 2005

# Import system modules
import arcgisscripting

# Create the Geoprocessor object
gp = arcgisscripting.create()

try:
    # Set local variables
    InFlowDirectionRaster = "C:/data/flowdir"
    OutRaster = "C:/data/basin"    

    # Check out Spatial Analyst extension license
    gp.CheckOutExtension("Spatial")

    # Process: Basin
    gp.Basin_sa(InFlowDirectionRaster, OutRaster)

except:
    # If an error occurred while running a tool, then print the messages.
    print gp.GetMessages()

Basin(<dir_grid>)

Parameter	Explanation
<dir_grid>	A raster showing direction of flow out of each cell. This can be created using the FlowDirection function.

Map Algebra example

basin(flowdir)					
basin(flowdirection(elev))

IHydrologyOp::Basin (directionRaster As IGeoDataset) As IGeoDataset

Parameter	Explanation
directionRaster	An input Raster, RasterDataset, RasterBand, or RasterDescriptor showing the direction of flow out of each cell. This Raster can be created using the IHydrologyOp::FlowDirection method.

ArcObjects example

' Create the RasterHydrologyOp object
Dim pHydrologyOp As IHydrologyOp
Set pHydrologyOp = New RasterHydrologyOp

' Declare the input raster object
Dim pDirectionDataset As IGeoDataset

' Calls function to open the direction raster dataset from disk
Set pDirectionDataset = OpenRasterDataset ("D:\SpatialData", "direction")

' Declare the output raster
Dim pOutputRaster As IGeoDataset

' Calls the method
Set pOutputRaster = pHydrologyOp.Basin (pDirectionDataset)

Fill

Sink

Flow Accumulation

An overview of the Hydrology tools