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Modelling Exposure through Earth’s Observation Routines

This is a three-year project funded by the UK Space Agency to develop an innovative application of Earth Observation (EO) technologies that will improve the understanding of disaster exposure. The project focuses on two pilot countries - Nepal and Tanzania. Meteor involves eight consortium organizations from across four continents. Their expertise spans from humanitarian aid to remote sensing and disaster risk reduction to policy advice.

HOT is working on digitizing buildings on homogeneous zone from the tasking manager to create data sets that will be used to create the model.

HOT Tasking Manager

The tasking manager is an OSM tool to manage, create and open tasks to help mappers add features easily. In this project the task were created from Homogeneous zones sampled in different areas such as planned, unplanned, scattered and less populated areas. Using QGIS software, we split homogeneous zones into multiple polygons for tasks creation in geojson format. The geojson for the multiple polygons are used to create the area of interest in the tasking manager for projects. Some parts of these areas were already mapped and contained some metadata so specific instructions were issued such as insisting mappers not delete any existing features and values inside them but rather fix the errors like connectivity and shapes of the existing building. The following are steps for task creation in the tasking manager.

Tasking Manager in project creation

1. Splitting the combined homogeneous zones into multiple polygons to make it simple for tasks creation. QGIS was used to split these zones in geojson format and direct use it for identification of an area of interest in Tasking manager for task creation and name tasks according to specific area.

2. The tasks are generated in forms of either arbitrary or square tasks, some were arbitrary and some were square tasks.

3. Adding description and instructions of the project, i.e general instruction for the project explains what is the project about, and specific instructions include what a mapper should do on a specific task example Image to be used, what features are priority (buildings or roads)

4. Save changes and publish the project ready for mapping.

Imagery used

The imagery used was provided by the Ministry of Lands, Housing and Human Settlements named COWI company imagery.

Building quantity and quality statistics, pre and post digitization

10,691 were digitized and mappers also worked of fixing error and shapes the existing tiles without deleting them (this is normally done as an appreciation to the previous mapper- deleting object in OSM is discouraged). The quality of data after digitization were relatively higher as high resolution image was used and mappers were experienced.

Pre and post maps of homogeneous zones