Flood Module
This document provides a short overview on how the Copernicus’s Data Access Service can be applied for more advanced use cases of working with GloFAS data.

 
Introduction
Alongside an interactive webmap, GloFAS provides access to datasets via a dedicated data service.

• GloFAS provides various ways of accessing datasets, these include:
• Copernicus Climate Data Store (CDS)
• File transfer Protocol (FTP)
• Meteorological Archival and Retrieval System (MARS)
• Web Map Service

In the following sections, each of the above data access services is explored in more detail.

Copernicus Climate Data Store
The CDS provides a single point of access to a wide range of quality-assured climate datasets including observations, historic climate data records, estimates of essential climate variables (ECVs) derived from Earth Observations, global and regional climate reanalysis of past observations, seasonal forecasts and climate projections. Access to these datasets is open, free and unrestricted.

In addition, the CDS provides a set of tools under its innovative toolbox that allows users to analyze and predict climate variables. The toolbox is specifically designed to handle requests from different users with different needs by facilitating the processing of large volumes of data as well as creation of simple visualizations based on multiple data sources. CDS datasets are primarily available in GRIB format or NetCDF.

The CDS can be accessed via the URL https://cds.climate.copernicus.eu/#!/home. A user account is required, but an existing GloFAS account can be used for login. Once logged in the user is led to the CDS homepage as shown in Figure 1.

The CDS provides access to the Copernicus Climate Change Service (C3S) data products via a catalog that allows a user to search and filter datasets of interest based on their features and unique identifiers e. g. product names, service providers.

Once the desired dataset is identified, the user can select it by clicking the header of the dataset. This will lead to a page containing the overview of the dataset and the download options as shown in Figure 2. The download button will lead to a data request form that the user can fill information about the metadata of the dataset to form a valid data request query. Once a valid request generated via the form is constructed, the user has the following options to download the data:

• Submit the form and download the data by click of a button in form NETCDF or GRIB format.
• Show query as an API request.
• Show the query as a toolbox request (applies for datasets that are accessible via the toolbox).

CDS ToolBox
The Climate data store toolbox provides a link between a powerful cloud computing power and raw datasets via a programming interface. The toolbox provides an interface for the user to create applications based on Python programming language and run them on the CDS computer. Some of the generic applications that can be created in the toolbox include data retrieval, making calculations based on the data and visualization of datasets in form of plots that can also be exported in form of PNG, JPEG.

The toolbox interface is composed of three different components as shown in Figure 6.

The following links are important in the use of the toolbox:

To access the toolbox the following link: https://cds.climate.copernicus.eu/cdsapp#!/toolbox

Documentation on how to use the toolbox: https://cds.climate.copernicus.eu/toolbox/doc/index.html

Toolbox editor can be accessed directly: https://cds.climate.copernicus.eu/user/login?destination=/toolbox-user

API reference for the toolbox: https://cds.climate.copernicus.eu/toolbox/doc/api.html

Toolbox application gallery containing example applications: https://cds.climate.copernicus.eu/toolbox/doc/gallery/index.html

File Transfer Protocol
GloFAS provides the possibility to access river flow forecasts and reforecasts through a dedicated file transfer protocol service (FTP). The File Transfer Protocol is only available upon request. Request for real-time forecasts or forecast reruns or any other inquiry and feedback service can be made using the contact us page on the GloFAS website.

When making a data request via an FTP, the following information is required alongside the period of simulation requested:

• When requesting data for stations or points (only for river sections with upstream areas larger than 1000 km2), station ID, name of stations, name of rivers, name of country, station latitude/longitude and station upstream areas
• When requesting data for areas, latitude and longitude of the bounding box region.

 Meteorological Archival and Retrieval System
The Meteorological Archival and Retrieval System (MARS) is a dedicated data access service that is available for ECMWF registered users. An ECMWF account can be requested by sending an email to efas@emwf.int

The MARS has the following features:

• Facilities to archive and retrieve environmental data
• 24/7 service
• Batch and interactive models
• Large amount of data, both in size and number of items stored
• Large number of users with different requirements.

 Accessing GloFAS data via Web Map Service in GIS
A web map service is an Open Geospatial Consortium (OGC) standard service of sharing spatial datasets. A web Map service can be accessed via a browser interface or in a GIS environment.

To access the WMS in a GIS environment, the following steps can be followed:

Launch QGIS and in the browser panel, right click on the WMS/WMST icon

In the subsequent create a new wms/wmts connection window insert a title for your WMS connection in the name section and paste the WMS url https://ows.globalfloods.eu/glofas-ows/ows.py?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetCapabilities and click OK (Figure 7).