2. Example data

This folder contains example shapefiles that can be used to reproduce the Bow at Banff case presented in the paper that describes this workflow. Shapefiles are derived from the MERIT Hydro basins (Lin et al., 2019). The Bow at Banff example case is a SUMMA setup that has 51 Grouped Response Units (GRUs) that are subdivided into 118 Hydrologic Response Units (HRUs) total.

2.1. Shapefiles used for Bow at Banff

The following shapefiles are the basis of the Bow at Banff setup:

1. For SUMMA (./shapefiles/catchment/): a shapefile outlining the subcatchments (GRUs) of the Bow River up to Banff, and how these GRUs are subdivided into Hydrologic Response Units (HRUs) by elevation bands;

2. For mizuRoute (./shapefiles/river_basins/): a shapefile that shows the routing basins. In this case these are identical to the SUMMA GRUs. This means that no routing remapping file is needed (see mizuRoute setup code for details about the remapping file). This also means that the IDs of the routing basins must be identical to the IDs assigned to the SUMMA GRUs. If these are not identical, mizuRoute will not be able to find the data for each routing basin in the SUMMA output files.

3. For mizuRoute (./shapefiles/river_network/): a shapefile that shows the river network that connects the routing basins.

2.2. Shapefile requirements

Each shapefile needs to contain certain bits of information in addition to the shape geometry. These are described below as follows:

• Name in example file: Column name used in the shapefile. These are arbitrary and must be specified in the workflow control file.

• Description: brief explanation of the data in the column.

• Units: units this variable must be in, if any.

• Control file variable: how this particular piece of information is referred to in the control files. Shows which line in the control file must be updated if the shapefile uses a different column name for this variable.

All shapefiles are expected to be in regular lat/lon format (WGS84; EPSG:4326).

2.2.1. Catchment shapefile

A shapefile that shows which basins will be SUMMA’s Grouped Response Units (GRUs) and optionally how the GRUs are divided into Hydrologic Response Units (HRUs). Also needs centroid latitude and longitude and HRU area.

• File name: shapefiles/catchment/bow_distributed_elevation_zone.shp

• Geographical projection: EPSG:4326

Name in example file	Description	Units	Control file variable
GRU_ID	GRU identifier	-	catchment_shp_gruid
HRU_ID	Unique HRU identifier	-	catchment_shp_hruid
center_lat	Centroid latitude	degree	catchment_shp_lat
center_lon	Centroid longitude	degree	catchment_shp_lon
HRU_area	Area of each HRU	m^2	catchment_shp_area

Note 1: HRU IDs must be unique. GRU IDs need not be, because multiple HRUs can be defined within a single GRU.

Note 2: centroid location and area should be calculated in an equal-area projection such as EPSG:6933 for accuracy. Centroid points then need to be converted to lat/lon.

2.2.2. River network shapefile

A shapefile that shows the river network that connects the routing basins. Segments that have no downstream segment (i.e. outlets) should be inciated by setting their downstream segment ID to 0 or a negative value. Also needs river segment slope and length.

• File name: shapefiles/river_network/bow_river_network_from_merit_hydro.shp

• Geographical projection: EPSG:4326

Name in example file	Description	Units	Control file variable
COMID	Stream segment identifier	-	river_network_shp_segid
NextDownID	ID of downstream segment	-	river_network_shp_downsegid
slope	Stream segment mean slope	-	river_network_shp_slope
length	Stream segment length	m	river_network_shp_length

In a basic model setup, it is assumed that the stream segments have a surrounding basin that maps 1:1 onto SUMMA’s GRUs. If this is not the case and the drainage basins used for routing do not map directly onto the SUMMA GRUs, a routing basins shapefile needs to be provided as well. See below.

2.2.3. Routing basin shapefile

A shapefile that shows the routing basins. Routing basins in the Bow at Banff case are identical to SUMMA GRUs. Also needs routing basin area and the ID of the stream segment the basin connects to.

• File name: shapefiles/river_basins/bow_distributed.shp

• Geographical projection: EPSG:4326

Name in example file	Description	Units	Control file variable
COMID	Routing basin identifier	-	river_basin_shp_rm_hruid
area	Area of each routing basin	m^2	river_basin_shp_area
hru_to_seg	Stream segment each basin connects to	-	river_basin_shp_hru_to_seg

Note: mizuRoute only uses the concept of HRUs in constrast to SUMMA’s use of both GRUs and HRUs. In most setups, it makes sense to define SUMMA’s GRUs as equal to mizuRoute HRUs, and let SUMMA worry about the routing inside each of the SUMMA-GRUs. The workflow setup code makes this assumption and cannot be used to create a mizuRoute setup that runs routing between SUMMA’s HRUs (e.g. in the Bow at Banff case this would refer to routing between the different elevation bands) - SUMMA should and does handle this.

2.3. References

Lin, P., M. Pan, H. E., Beck, Y. Yang, D. Yamazaki, R. Frasson, C. H. David, M. Durand, T. M. Pavelsky, G. H. Allen, C. J. Gleason, and E. F. Wood, 2019: Global reconstruction of naturalized river flows at 2.94 million reaches. Water Resources Research, doi:10.1029/2019WR025287.