Create data downloader

[mcmancini]

Create a downloader for the Soil data. We will start with the SoilGrids dataset;
it was downloaded using the soilgrids 0.1.3 library. Docs can be found here.

The idea here is to have two functionalities implemented:

• on-demand download through geographic querying (e.g., passing a lon-lat pair, or an OS grid code for the UK) the relevant soil data from the SoilGrids API. Data in this case is not saved to disk.
• Bulk download of soil data from a geographic area defined with a bounding box to be saved on disk in .netCDF format.

The way I am thinking of building this is as follows:

• We create a SoilApp object, which the user needs to initialise as follows: soil_app = SoilApp()
• This object contains two methods: download() and bulk_download()
• download() takes as only argument a dictionary containing either {'lon': longitude, 'lat': latitude} coordinates or {'OS_code': os_grid_code}
• bulk_download() which requires the coordinates defining the rectangular bounding box of the area of interest and the path in which the downloaded data will be stored as follows:
  • xmin = the longitude of the left corners of the bounding box of interest;
  • xmax = the longitude of the right corners of the bounding box of interest;
  • ymin = the latitude of the bottom corners of the bounding box of interest;
  • ymax = the latitude of the top corners of the bounding box of interest.
  • save_path = the directory in which the downloaded data will be stored.

At a later stage, we will add the possibility of downloading data also from the World Harmonized Soil Database