The OSGeo United Nations (UN) Committee promotes the development and use of open source software that meets UN needs and supports the aims of the UN. Following a meeting between the OSGeo Board of Directors and the UN GIS team at the FOSS4G conference in Seoul, Korea, in September 2015, the Committee has mainly worked on the UN Open GIS Initiative, a project "... to identify and develop an Open Source GIS bundle that meets the requirements of UN operations, taking full advantage of the expertise of mission partners including partner nations, technology contributing countries, international organisations, academia, NGOs, private sector". In 2018, the OSGeo UN Committee called for proposals for developing open geospatial educational materials as a part of its activities. There were three challenges: the first two (one of them sponsored by Boundless) are related to the UN Open GIS Initiative.

The first challenge, related to UN Open GIS - Spiral 1, aims at the development of education material that teaches users how to apply the GeoSHAPE platform. GeoSHAPE is a free and open source geospatial collaborative platform created from various open source projects. The developed material provides a guide on how to create, edit and share critical data on an integrated dynamic map in near real time, view map updates by users from anywhere in the world and use GeoSHAPE exchange in connected and disconnected environments. The course is structured with content to suit novice, intermediate and advanced users.

The second challenge supports UN Open GIS - Spiral 3, which provides geo-analytical solutions for the UN. The feasibility of the analytical functions developed as part of Spiral 3 were tested against an Ebola Epidemic use case. Requirements for developing suitable applications and methodologies based on actual UN operational cases were defined in 2017. Members of the UN Open GIS - Spiral 3 developed a geo-analytical library, called "Processing Toolbox", which is a plug-in for uDig, an open source desktop GIS. The training material developed in the frame of the OSGeo UN Challenge provides an introduction to the use of the algorithms for environmental analysis in the uDig Processing Toolbox, specifically those related to ecology and ecosystems identification. The training material for Spiral 3 is designed as a step-by-step tutorial, using algorithms in the uDig Processing Toolbox. While working through the tutorial, the user is familiarized with the tools covering all the available macro sections. After completing the tutorial, a user will be able to find the needed algorithms to solve a specific use case.

The presentation deals with the description of the UN Open GIS Challenge and the open training materials developed under this initiative. The material is available under an open license and can therefore be reused by anybody.

The climate change and the recent extreme events occurred all over the world draw again the attention to the natural hazards both for prevention and for management aspects. In this context, environmental modelling can help in mapping hazards and risks zones and to support decision makers in building functional infrastructures with low environment impact and for a safe urban planning.
In the last decades many researchers tried to extract useful information from digital data and in particular from Digital Terrain Models (DTM) with the development of ad-hoc algorithms and tools. In the meanwhile the data availability increased and high precision DTM are available almost all over the world.
The algorithms contained in the HortonMachine library are the result of more than 10 years of research, development and real application of people from different research institutes and professionals working in the field of environmental engineering. The HortonMachine library contains tools for data management, data collection in the field, and environmental modelling in particular related to hillslope stability, floods, debris flow, forestry management and woody floods.