Climate

Weather generator data and weather stations are required for SWAT+ to run.

SWAT+ Documentation

ClimateSWAT+ Documentation

Read the SWAT+ Input/Output Documentation for Climate

Weather Stations

Weather stations are linked from all of your connection objects (channels, HRUs, etc.) in SWAT+. If you are coming from QSWAT+, it is much better to import stations either from the weather generator section, or the observed weather file importer than it is to create them manually.

By importing through one of the methods described below, your new stations will be automatically matched your spatial connection objects.

Import Weather Generator Data

Click the import data button to import weather generator (wgn) data for your project. If you installed the SWAT+ databases, this file will be selected by default along with the CFSR world table. USA wgn data is also available from this database; type wgn_us to use this table.

You may also add your own data to this database using the wgn and corresponding wgn_mon tables.

How to Use SQLite

Below the table name field is a check box asking if you are using observed weather data. By default (unchecked), when you click start import, weather stations will be created based on your wgn locations. If you are using observed weather data and prefer to have weather stations created based on this data, check this box--stations will not be created when you start import, and instead they will be created for you when you import your observed weather data files.

If you are not using observed weather data, it is important to leave the box unchecked so that weather stations are created for you.

CSV Import

If you do not want to use the SQLite database, you may import CSV files of your weather generator data. Two CSV files are required.

1. Stations CSV file:

   • Columns id, name, lat, lon, elev, rain_yrs

   • id should be uniquely numbered

2. Monthly values CSV file:

   • Columns id, wgn_id, month, tmp_max_ave, tmp_min_ave, tmp_max_sd, tmp_min_sd, pcp_ave, pcp_sd, pcp_skew, wet_dry, wet_wet, pcp_days, pcp_hhr, slr_ave, dew_ave, wnd_ave

   • id should be uniquely numbered

   • wgn_id corresponds to the id column from the stations file

Import Observed Weather Data

Import observed weather data from the top of the weather stations section. The data files may be in one of two formats: SWAT2012/Global Weather Data CFSR website format, or SWAT+.

After importing observed weather data, be sure to check your simulation run time to match your weather dates.

Please ensure the files you're importing are saved with UTF-8 encoding. Otherwise, you may get errors about reading the start date despite it appearing correctly formatted in your files.

You can open your files in Notepad++ and change the encoding via the Encoding menu in the top toolbar. It must be only UTF-8, not other variations.

SWAT2012/Global Weather Websites Format

Each measurement included in your data must have the following entry file names:

Measurement	Entry File
Precipitation	pcp.txt
Temperature	tmp.txt
Solar radiation	solar.txt
Relative humidity	rh.txt
Wind speed	wind.txt

Each entry file is a comma-separated list of stations. Each station name should have a corresponding .txt file (e.g., name p326-963 should have a p326-963.txt file).

ID	Name	Latitude	Longitude	Elevation
1	p326-963	32.628	-96.250	142.0

Each station file should have the first line as the starting day as YYYYMMDD (e.g., 19790101). The following lines are the measurement for each day, one line per day. For temperature, each line will be max,min (e.g., 10.138,-2.662).

Global weather data options are available on the SWAT website.

SWAT+ Format

Each measurement included in your data must have the following entry file names:

Measurement	Entry File
Precipitation	pcp.cli
Temperature	tmp.cli
Solar radiation	slr.cli
Relative humidity	hmd.cli
Wind speed	wnd.cli

Each entry file has a title line (any text allowed), followed by a heading line, followed by a list of filenames for each station. Filenames should be listed alphabetically.

pcp.cli: precipitation file names
filename
p326953.pcp
p326956.pcp

Each station file has a title line, followed by a heading line and data line for time and location. Measurements for each timestep are in the lines to follow. For temperature, the measurements will be listed as max then min.

Weather Generator Parameters

SWAT+ Input File	Database Tables
weather-wgn.cli	weather_wgn_cli
	weather_wgn_cli_mon

weather_wgn_cli

Field	Type	Description	Units	Range
id	int	Auto-assigned identifier
name	text	Name of weather generator
lat	real	Latitude of weather station	deg.	+/-90
lon	real	Longitude of weather station	deg.	+/-180
elev	real	Elevation of weather station	m	0-5000
rain_yrs	int	Number of years of recorded maximum monthly 0.5h rainfall data		5-100

weather_wgn_cli_mon

Each entry in weather_wgn_cli will have 12 rows in weather_wgn_cli_mon.

Field	Type	Description	Units	Range
id	int	Auto-assigned identifier
wgn_id	int	ID of row in weather_wgn_cli
month	int	Month
tmp_max_ave	real	Average or mean daily maximum air temperature for month	°C	-30-50
tmp_min_ave	real	Average or mean daily minimum air temperature for month	°C	-40-40
tmp_max_sd	real	Standard deviation for daily maximum air temperature in month	°C	0.1-100
tmp_min_sd	real	Standard deviation for daily minimum air temperature in month	°C	0.1-30
pcp_ave	real	Average or mean total monthly precipitation	mm	0-600
pcp_sd	real	Standard deviation for the average daily precipitation	mm/day	0.1-50
pcp_skew	real	Skew coefficient for the average daily precipitation	mm	-50-20
wet_dry	real	Probability of a wet day after a dry day		0-0.95
wet_wet	real	Probability of a wet day after a wet day		0-0.95
pcp_days	real	Average number of days of precipitation in a month		0-31
pcp_hhr	real	Maximum 0.5 hour rainfall in entire period of record for month	mm	0-125
slr_ave	real	Average daily solar radiation for the month	MJ/m^2/day	0-750
dew_ave	real	Average daily dew point temperature for each month	°C	-50-25
wnd_ave	real	Average wind speed for the month	m/s	0-100

Weather Stations Parameters

SWAT+ Input File	Database Tables
weather-sta.cli	weather_sta_cli
	weather_file

weather_sta_cli

When entering an observed weather file name in the station editor, you may start typing to search for existing weather files adding during the import step. If adding observed files manually, just type the name of the file (e.g., p326953.pcp), and put that file in the directory you plan to write input files (e.g., your TxtInOut). Files must be in SWAT+ format. If your weather data is in SWAT2012 format or from the Global Weather CFSR website, please use the import step to convert them to SWAT+.

Field	Type	Description
id	int	Auto-assigned identifier
name	text	Name of the weather station
wgn_id	int	ID of row in weather_wgn_cli
pcp	text	Precipitation gage filename or "sim" if simulated
tmp	text	Temperature gage filename or "sim" if simulated
slr	text	Solar radiation gage filename or "sim" if simulated
hmd	text	Relative humidity gage filename or "sim" if simulated
wnd	text	Wind speed gage filename or "sim" if simulated
wnd_dir	text	Wind direction gage filename
atmo_dep	text	Atmospheric deposition data file name
lat	real	Latitude of weather station
lon	real	Longitude of weather station

weather_file

This table is only used if you import observed weather data files. If entering stations manually, this table will not be populated.

Field	Type	Description
id	int	Auto-assigned identifier
filename	text	Name of the weather data file
type	text	Type of weather data: pcp, tmp, slr, hmd, wnd
lat	real	Latitude of weather station in file
lon	real	Longitude of weather station in file