Question about landcover layer attribution

[mwrona-avs]

Hello, I have a question regarding the landcover layer attribution, as it is unclear to me.

It seems that the landcover layer uses data from Daylight, which in turn uses data from ESA WorldCover. This is stated in the docs and in the license data:

• https://docs.protomaps.com/basemaps/layers#landcover
• https://github.com/protomaps/basemaps/blob/main/LICENSE_DATA.md#daylight-landcover

It also seems that the landcover layer is included in the daily basemap builds.

Looking at the ESA website, using the ESA WorldCover dataset requires attribution:

If you are using the data as a layer in a published map, please include the following attribution text:

© ESA WorldCover project [year] / Contains modified Copernicus Sentinel data ([year]) processed by ESA WorldCover consortium
With year either 2020 or 2021 for the WorldCover 2020 and 2021 map, respectively.

However, the basemap attribution contains only OpenStreetMap.

Additionally, when building a custom basemap, it seems that data from Daylight / ESA WorldCover is also included by default.

So my questions are:

1. Do the daily basemap builds include data from the ESA WorldCover dataset?
2. When building a custom basemap, is data from the ESA WorldCover dataset included?
3. If so, is attribution required alongside OpenStreetMap — for ESA WorldCover, Daylight, or both?
4. If ESA WorldCover attribution is required, which year's data is used to produce the daily builds — WorldCover 2020 or WorldCover 2021?

Thanks in advance - I want to make sure I'm attributing the data correctly.

[bdon]

However, the basemap attribution contains only OpenStreetMap.

You are referring to the attribution in the corner of an interactive web map ("corner attribution") and not attribution-required licenses in general, such as Creative Commons CC-BY. It's a well established convention by the OpenStreetMap foundation to attribute "© OpenStreetMap" in the corner of interactive maps: https://osmfoundation.org/wiki/Licence/Attribution_Guidelines but other licenses requiring attribution are not explicit about the form of attribution.

Using corner attribution for the name and links of every CC-BY dataset that's part of OSM or Daylight would not fit in limited screen size, so the data license markdown file in this repo provides sources for where the data came from:

https://github.com/protomaps/basemaps/blob/main/LICENSE_DATA.md#daylight-landcover

For your specific questions:

Do the daily basemap builds include data from the ESA WorldCover dataset?

Yes, because they depend on the Daylight dataset for the landcover.

When building a custom basemap, is data from the ESA WorldCover dataset included?

Yes, if you are using the basemaps profile unmodified for a custom area, otherwise comment out this: https://github.com/protomaps/basemaps/blob/main/tiles/src/main/java/com/protomaps/basemap/Basemap.java#L313

If so, is attribution required alongside OpenStreetMap — for ESA WorldCover, Daylight, or both?

Yes, because ESA WorldCover is a CC-BY source, so you would need attribution in some form depending on how your project is distributed. I am open to suggestions on better attribution guidelines, example: having a (more) link in the corner that links out to LICENSE_DATA.md in this repository

If ESA WorldCover attribution is required, which year's data is used to produce the daily builds — WorldCover 2020 or WorldCover 2021?

I'm not certain which one the last Daylight build uses but if you can determine this from the dataset that would be useful for others.

[mwrona-avs]

Thank you for the clarification on the difference between corner attribution and attribution-required licenses in general. I had incorrectly assumed that ESA's attribution requirement meant attribution in the map corner.

I am open to suggestions on better attribution guidelines, example: having a (more) link in the corner that links out to LICENSE_DATA.md in this repository

A (more) link in the corner sounds like a good idea. Another option could be a sample attribution snippet for the layers included in the daily builds — actual ready-to-use attribution text.

I'm not certain which one the last Daylight build uses but if you can determine this from the dataset that would be useful for others.

Unfortunately, I wasn't able to determine this from the file used in the repo (https://r2-public.protomaps.com/datasets/daylight-landcover.gpkg). I'll assume the year 2020, as stated in the Daylight announcement: https://daylightmap.org/2023/10/11/landcover.html.

Thanks again for taking the time to answer all my questions!