CHM (Canadian Hydrological Model)
Related Information
Forcing Data Description
Features
Workflow
Section 1: Forcing Data Description
Hydrological Model
CHM (Canadian Hydrological Model)
Required Data
1. total precipitation [kg m-2]
2. air temperature [oC]
3. humidity [%]
4. wind [m s-1]
5. wind direction [deg]
6. incoming shortwave radiation [W m-2]
7. optionally, longwave [W m-2]
Data Sources
Station (ECCC & Provinces)
● CaPA + GEM (from ECCC)
Spatial Resolution
Flexible spatial; Point/HRU scale
Temporal Resolution
Sub-daily, ideally hourly or less
File Format
● Input is .nc in lat/long grid with time
● Timeseries per station stored in flat ASCII
Section 2: Features
Strengths and Limitations
● Requires constant meteorological forcing data timesteps
External and Internal Tools
● Python (xarray/pandas or R (dplyr) used to convert existing met data to CHM format.
● WindMapper generates wind speedup maps for spatial interpolation of wind (python)
● Modules exist to spatially interpolate the point data using lapse rate methods
Source Code Availability
Section 3: Workflow
Model Workflow
1. Download raw forcing data
2. Bias correction to lower wind speed and correct precipitation undercatch using filters
3. Convert met data to CHM format using external tools
Notes
T-2020-05-09-81nhOTJVAh0q93p83uhT81Zcg Forcing Data Descriptor Template for Hydrological Models 1.0