ArcObjects Library Reference (SpatialAnalyst)

IHydrologyOp.FlowAccumulation Method

Creates a raster of accumulated flow to each cell.

[Visual Basic .NET]
Public Function FlowAccumulation ( _
    ByVal directionRaster As IGeoDataset, _
    [ByRef weightRaster As Object] _
) As IGeoDataset

[C#]
public IGeoDataset FlowAccumulation (
    IGeoDataset directionRaster,
    ref object weightRaster
);

[C#]

Optional Values

weightRaster To indicate that this parameter is undefined, first define a variable object Missing=Type.Missing; then pass this in as ref Missing.

[C++]
HRESULT FlowAccumulation(
  IGeoDataset* directionRaster,
  VARIANT* weightRaster,
  IGeoDataset** FlowAccumulation
);

[C++]

Parameters
directionRaster [in]

  directionRaster is a parameter of type IGeoDataset
weightRaster [optional]
  weightRaster is a parameter of type VARIANT

  To indicate this parameter is undefined pass a reference to a VARIANT with type VT_ERROR and scode value of DISP_E_PARAMNOTFOUND.
FlowAccumulation [out, retval]

  FlowAccumulation is a parameter of type IGeoDataset

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server. Requires Spatial Analyst Extension.

Remarks

directionRaster	a raster showing direction of flow out of each cell This can be created using the IHydrologyOp::FlowDirection method.
[weightRaster]	the weight to be assigned to each cell If no [weightRaster] is specified, a default weight of one will be applied to each cell. For each cell in the output, the result will be the number of cells that flow into it. The data type for the weightRaster can be any Raster object that supports IGeoDataset (e.g., Raster, Raster band, etc.).

The method returns a reference to a Raster object.
Read the Working with ArcGIS Spatial Analyst objects technical document for general information on implementing Spatial Analyst operations.

IHydrologyOp.FlowAccumulation Method

Product Availability

Remarks

See Also