Defining a model region

To setup a model for a specific region, you can use several geospatial or hydrographic region definitions which are explained in this chapter. The syntax is interpreted using the parse_region() method. For hydrographic regions see also the delineate basins example and get_basin_geometry() method.

Note

All x and y coordinates in the point and bbox are in the EPSG:4326 (WGS84) coordinate reference system.

Geospatial region

Bounding box (bbox): {'bbox': [xmin, ymin, xmax, ymax]}

Geometry file (geom): {'geom': '/path/to/geometry_file'}

Based on another model: {'<model_name>': '/path/to/model_root'}

Based on a raster file: {'grid': '/path/to/raster_file'}

Based on a mesh file: {'mesh': '/path/to/mesh_file'}

Hydrographic region

The following hydrographic regions are supported:

• basin

• subbasin

• interbasin

Basin: is defined by the entire area which drains to the sea or an inland depression. To delineate the basin(s) touching a region or point location, users can supply the following:

• One point location: {'basin': [x, y]}

• More point locations: {'basin': [[x1, x2, ..], [y1, y2, ..]]}

• Bounding box: {'basin': [xmin, ymin, xmax, ymax]}

• Geometry file: {'basin': '/path/to/geometry_file'}

• Single unique basin ID: {'basin': [ID1]}

• Several unique basin ID: {'basin': [ID1, ID2, ..]}

To filter basins, variable-threshold pairs to define streams can be used in combination with a bounding box or geometry file, e.g.: 'uparea':30 to filter based on streams with a minimum drainage area of 30 km2 or 'strord':8 to filter basins based on streams with a minimal stream order of 8. The variables should be available in the dataset on which the delineation is based, e.g. Hydro MERIT.

• {'basin': [xmin, ymin, xmax, ymax], '<variable>': threshold}

To only select basins with their outlet location use 'outlets': true in combination with a bounding box or geometry file

• {'basin': [xmin, ymin, xmax, ymax], 'outlets': true}

Subbasin: is defined by the area that drains into an outlet, stream or region. Users can supply the following:

• One point location: {'subbasin': [x, y]}

• More point locations: {'subbasin': [[x1, x2, ..], [y1, y2, ..]]}

• Bounding box: {'subbasin': [xmin, ymin, xmax, ymax]}

• Geometry file: {'subbasin': '/path/to/geometry_file'}

To speed up the delineation process users can supply an estimated initial bounding box in combination with all the options mentioned above. A warning will be raised if the bounding box does not contain all upstream area.

• {'subbasin': [x, y], 'bounds': [xmin, ymin, xmax, ymax]}

The subbasins can further be refined based on one (or more) variable-threshold pair(s) to define streams, as described above for basins. If used in combination with point outlet locations, these are snapped to the nearest stream which meets the threshold criteria.

• {'subbasin': [x, y], '<variable>': threshold}

Interbasin: is defined by the area that drains into an outlet or stream and bounded by a region and therefore does not necessarily including all upstream area. Users should supply a bounding region in combination with stream and/or outlet arguments. The bounding region is defined by a bounding box or a geometry file; streams by a (or more) variable-threshold pair(s) and outlet by point location coordinates. Similar to subbasins, point locations are snapped to nearest downstream stream if combined with stream arguments.

• {'interbasin': [xmin, ymin, xmax, ymax], '<variable>': threshold}

• {'interbasin': /path/to/geometry_file, '<variable>': threshold}

• {'interbasin': [xmin, ymin, xmax, ymax], '<variable>': threshold, 'xy': [x, y]}

To only select interbasins based on the outlet location of the entire basins use 'outlets': true

{'interbasin': [xmin, ymin, xmax, ymax], 'outlets': true}