[R-sig-Geo] LandGIS Open Land data service - global stack of environmental layers

[Tomislav Hengl]

We have recently released a webmapping system to serve global consistent 
environmental and Earth science layers at spatial resolutions from 10 km 
to 250 m (hopefully also soon at 100 m). This is an Open Data system as 
majority of layers are distributed under the Open Data Commons Open 
Database License (ODbL) and/or Creative Commons Attribution-ShareAlike 
4.0 International license (CC BY-SA). Read more about LandGIS in: 
http://opengeohub.org/about-landgis.

You can access the web app at:

https://landgis.opengeohub.org

The system currently (Jan 2019) serves about 300+ layers from relief and 
geology, to vegetation indices, climatic images, soil properties and 
classes and potential and actual vegetation. Complete overview of 
available layers is available at:

https://github.com/Envirometrix/LandGISmaps

In addition to the web-mapping app, data can be accessed using the:

- Geonode installation at https://maps.opengeohub.org,
- LandGIS REST API services at https://landgisapi.opengeohub.org,
- LandGIS WCS at https://geoserver.opengeohub.org/landgisgeoserver/web/,

A copy of all layers is also available via Zenodo.org i.e. via an unique 
URL.

To access data at point locations best use the REST API. For example, to 
access monthly precipitations at a location X, Y you can use:

https://landgisapi.opengeohub.org/query/point?lat=7.58033&lon=35.6561&coll=layers1km&regex=clm_precipitation_imerge.(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)_m_1km_s0..0cm_.*_v0.1.tif

which returns a GeoJSON (table) with precipitation values in mm.

To access values of LandGIS layers at multiple points you can use:

curl -X POST --form "points=@test_points.geojson" --form 
"layer=pnv_fapar_proba.v.jul_d_1km_s0..0cm_2014..2017_v0.1.tif" 
https://landgisapi.opengeohub.org/query/points -o results.json

where test_points.geojson is the input GeoJSON file containing 
coordinates of points. The multi-point access is currently limited to 
max 20 points, but we hope to increase this number gradually. More 
examples of how to construct spatial queries are available at: 
https://landgisapi.opengeohub.org

In addition to the REST access, you can also access the LandGIS data 
using the Web Coverage Service (WCS) functionality of the Geoserver e.g. 
to subset layers using a bounding box. For example, to download surface 
temperature for July for an area of about 300 by 300 km you can use:

https://geoserver.opengeohub.org/landgisgeoserver/ows?service=WCS&version=2.0.1&
request=GetCoverage&
coverageId=layers1km:clm_lst_mod11a2.jul.day_m_1km_s0..0cm_2000..2017_v1.0&
subset=Lat(41,45)&subset=Long(32,35)

The read limit for WCS is 4GB and response size limit is 200MB. This 
means that WCS might fail if you try to fetch too large bounding boxes. 
If this happens we recommend instead downloading whole GeoTIFFs from Zenodo.

We are currently preparing R functionality to allow users fetching data 
from LandGIS in a more systematic way (import, overlay, subset, 
plot...). If you would like to contribute to this initiative, especially 
to testing the R functions, please send me an email. Also we would 
appreciate if you would report any bug or inconsistency you discover 
via: https://github.com/Envirometrix/LandGISmaps/issues

If you are currently producing any similar types of data (e.g. 
environmental layers at resolutions from 100 m to 1 km for a global land 
mask) and if you would like to publish this data on LandGIS, please 
forward a proposal for publishing your global layers: 
https://opengeohub.org/submitting-global-layers-inclusion-landgis and we 
will get on it asap.

thank you,

Tom Hengl
https://opengeohub.org/people/tom-hengl