Watershed
Compute watersheds in terrain elevation data in the specified Channel and output the watershed analysis in various forms. The Minimum flow parameter specifies the minimum total flow in the basin required to create a watershed area or stream line. Smaller Minimum flow values will result in many more, smaller areas or streams. Larger Minimum flow values will result in fewer, larger areas or streams. The Water channel parameter allows choosing a channel in the image that provides relative water amounts dropping onto each pixel.
Available Output operations:
areas - Create areas that show regions of common drainage and save to the specified vector Result destination.
downstream lines - Given a channel with terrain elevation data plus a drawing that contains points, create the stream line for each point by which water issuing from the point flows further downstream.
lines - Create lines that show networks of streams into which water flows within a region of common drainage.
sink areas - Create areas that show sinks, regions that are closed drainage basins. The areas created do not depend on minimum flow, since each area will cover all territory where rainfall drains into the same sink.
upstream areas - Given a channel with terrain elevation data plus a drawing that contains points, create watershed areas from which water drains into each point. Upstream areas computations usually only make sense for points that are located on a watershed stream line.
upstream lines - Given a channel with terrain elevation data plus a drawing that contains points, create the stream lines by which water drains into each point. Upstream lines computations usually only make sense for points that are located on a watershed stream line.
Fields created:
mfd_id - Manifold identity field.
Geom - The geometry of the area or stream watershed object.
Stream - The watershed identifier for the watershed area or stream line object into which water from this object flows.
Target - The watershed identifier for the watershed area or stream line object into which water from this object flows.
OrderShreve - Watershed order computed using Shreve ordering.
OrderStrahler - Watershed order computed using Strahler ordering.
Value - The flow contributed by this watershed object.
ValueSum - The total flow through this watershed object, including all flow from upstream watershed objects as well as flow from this object.
Launch the template by choosing a Tile field and then double-clicking the Watershed template. When the template launches we can specify options.
See the Watersheds topic for a detailed discussion and examples.
Watershed : areas
Create areas that show regions of common drainage and save to the specified vector Result destination.
Watershed : downstream lines
Given a channel with terrain elevation data plus a drawing that contains points, create the stream line for each point by which water issuing from the point flows further downstream.
Watershed : lines
Create lines that show networks of streams into which water flows within a region of common drainage.
Watershed : sink areas
Create areas that show sinks, regions that are closed drainage basins. The areas created do not depend on minimum flow, since each area will cover all territory where rainfall drains into the same sink.
Watershed : upstream areas
Given a channel with terrain elevation data plus a drawing that contains points, create watershed areas from which water drains into each point. Upstream areas computations usually only make sense for points that are located on a watershed stream line.
Watershed : upstream lines
Given a channel with terrain elevation data plus a drawing that contains points, create the stream lines by which water drains into each point. Upstream lines computations usually only make sense for points that are located on a watershed stream line.