ERDDAP
Easier access to data

Make A Graph

Dataset Title:	Monthly Freshwater Runoffs of the St. Lawrence at the Height of Quebec City \| Débits mensuels d'eau douce du Saint-Laurent à hauteur de la ville de Québec
Institution:	Fisheries and Oceans Canada (Dataset ID: mpoDebitsEauMensuels)
Range:	time = 1955-01-01 to 2026-05-01
Information:	Summary \| License \| Metadata \| Background \| Data Access Form \| Files

To work correctly, this web page requires that JavaScript be enabled in your browser. Please:
1) Enable JavaScript in your browser:
      • Chrome: "Settings : Advanced : Privacy and security : Site Settings : JavaScript"
      • Firefox: (it should be always on!)"
      • Opera: "Settings : Websites : JavaScript"
      • Safari: "Safari : Preferences : Security : Enable JavaScript"
2) Reload this web page.

Graph Type:

X Axis:

Y Axis:

Color:

Constraints	Optional Constraint #1		Optional Constraint #2

Server-side Functions

distinct()

Hover here to see a list of options. Click on an option to select it.

Graph Settings

Marker Type:

Size:

Color:

Color Bar:

Continuity:

Scale:

Minimum:

Maximum:

N Sections:

Y Axis Minimum:

Maximum:

(Please be patient. It may take a while to get the data.)

Optional:
Then set the File Type: (File Type information)
and

or view the URL:
(Documentation / Bypass this form

)

[The graph you specified. Please be patient.]

Things You Can Do With Your Graphs

Well, you can do anything you want with your graphs, of course. But some things you might not have considered are:

Web page authors can embed a graph of the latest data in a web page using HTML <img> tags.
Anyone can use ERDDAPs Slide Sorter to build a personal web page that displays graphs with the latest data (or other images or HTML content), each in its own, draggable slide.

The Dataset Attribute Structure (.das) for this Dataset

Attributes {
 s {
  time {
    String _CoordinateAxisType "Time";
    Float64 actual_range -4.733856e+8, 1.7775936e+9;
    String axis "T";
    String ioos_category "Time";
    String long_name "Date";
    String source_name "date";
    String standard_name "time";
    String time_origin "01-JAN-1970 00:00:00";
    String time_precision "1970-01-01";
    String units "seconds since 1970-01-01T00:00:00Z";
  }
  runoffs {
    Float32 _FillValue NaN;
    Float32 actual_range 7822.0, 25752.0;
    Float64 colorBarMaximum 90.0;
    Float64 colorBarMinimum -90.0;
    String long_name "freshwater_runoffs";
    String units "m^3/s";
  }
 }
  NC_GLOBAL {
    String cdm_data_type "Other";
    String Conventions "COARDS, CF-1.10, ACDD-1.3, NCCSV-1.2";
    String creator_name "Denis Lefaivre";
    String creator_type "institution";
    String defaultGraphQuery "lines";
    String history 
"2026-08-18T00:43:29Z (local files)
2026-08-18T00:43:29Z http://erddap.cioos.ca/tabledap/mpoDebitsEauMensuels.das";
    String infoUrl "https://catalogue.ogsl.ca/fr/dataset/ca-cioos_84a17ffc-4898-4261-94de-4a5ea2a9258d";
    String institution "Fisheries and Oceans Canada";
    String institution_fr "Pêches et Océans Canada";
    String institution_identifier "https://ror.org/02qa1x782";
    String keywords "freshwater, runoffs";
    String keywords_fr "débits, eau douce";
    String license "Open Government Licence - Canada";
    String licenseUrl "https://open.canada.ca/en/open-government-licence-canada";
    String related_datasets "https://erddap.ogsl.ca/erddap/tabledap/mpoDebitsEauQuotidiens.html";
    String sourceUrl "(local files)";
    String standard_name_vocabulary "CF Standard Name Table v55";
    String summary "This dataset presents the monthly mean runoff estimated using an empirical relationship between the St. Lawrence River discharge and the water-level at Neuville with the Bourgault and Koutitonsky (1999) method. The uncertainty is +/- 2100 m3/s at 95%.";
    String summary_fr "Ce jeu de données présente les débits mensuel d'eau douce calculés à partir d'une relation empirique entre le débit du fleuve Saint-Laurent et le niveau d'eau à Neuville  selon la méthode de Bourgault et Koutitonsky (1999). L'incertitude est de +/- 2100 m3/s à 95%.";
    String time_coverage_end "2026-05-01";
    String time_coverage_start "1955-01-01";
    String title "Monthly Freshwater Runoffs of the St. Lawrence at the Height of Quebec City | Débits mensuels d'eau douce du Saint-Laurent à hauteur de la ville de Québec";
    String update_frequency "Monthly";
  }
}

Using tabledap to Request Data and Graphs from Tabular Datasets

tabledap lets you request a data subset, a graph, or a map from a tabular dataset (for example, buoy data), via a specially formed URL. tabledap uses the OPeNDAP (external link)

Data Access Protocol (DAP) (external link)

and its selection constraints (external link)

The URL specifies what you want: the dataset, a description of the graph or the subset of the data, and the file type for the response.

(easy) You can get data by using the dataset's Data Access Form or Subset form. They make the URL for you.
(easy) You can make a graph or map by using the dataset's Make A Graph form. It makes the URL for you.
(not hard) You can bypass the forms and get the data or make a graph or map by generating the URL by hand or with a computer program or script.

Tabledap request URLs must be in the form
https://coastwatch.pfeg.noaa.gov/erddap/tabledap/datasetID.fileType{?query}
For example,
https://coastwatch.pfeg.noaa.gov/erddap/tabledap/pmelTaoDySst.htmlTable?longitude,latitude,time,station,wmo_platform_code,T_25&time>=2015-05-23T12:00:00Z&time<=2015-05-31T12:00:00Z
Thus, the query is often a comma-separated list of desired variable names, followed by a collection of constraints (e.g., variable<value), each preceded by '&' (which is interpreted as "AND").

For details, see the tabledap Documentation.

ERDDAP, Version 2.28.1
Disclaimers | Privacy Policy | Contact