# Step 1: Understanding the requirements

In order to run wflow, several files are required. These consist of a settings file and input data. The input data is typically separated into static maps and forcing data, both are supplied in a NetCDF file, except for lake storage and rating curves that are supplied via CSV files. A brief overview of the different files:

• The settings.toml file contains information on the simulation period, links to the input files (and their names in the NetCDF files), and links the correct names of the variables in the NetCDF files to the variables and parameters of wflow.
• The staticmaps.nc file contains spatial information on the elevation, locations of the gauges, land-use, drainage direction, etc. This file can also contain maps with parameter values.
• The forcing.nc file contains the precipitation, temperature and potential evaporation time series (as a 3D array).

There are several model configurations supported by wflow. These model configurations require slightly different input requirements, yet the general structure is similar for each model. A wflow model configuration consists of a vertical concept like the SBM, HBV or FLEXTOPO vertical concept in combination with lateral concepts that control how water is routed for example over the land or river domain. For the wflow_sbm model different model configurations are possible. The following model configurations are supported in wflow:

• wflow_sbm:
• SBM + kinematic wave for subsurface and surface flow
• SBM + kinematic wave for subsurface and overland flow + local inertial river
• SBM + kinematic wave for subsurface flow + local inertial river (1D) and land (2D)
• SBM + groundwater flow + kinematic wave for surface flow
• wflow_hbv: HBV + kinematic wave for surface routing
• wflow_flextopo: FLEXTOPO + kinematic wave for surface routing
• wflow_sediment as post processing of wflow_sbm or wflow_hbv output

In the following pages, some examples will be given on how to prepare a basic wflow_sbm model. Example data for other model configurations is provided in the section with sample data.