Written by: Sheila Amalia and Tri Selasa Pagianti
During the preliminary survey, we acknowledged that there were only a few objects that were already mapped on OpenStreetMap (OSM) (https://www.openstreetmap.org/). Many objects such as buildings, tracks, and amenities were missing.
First, the buildings and roads that are visible in satellite imagery (Bing aerial Imagery) were mapped on OSM using OSM Tasking Manager. Below is the comparison of OSM data availability in the Nong Hoi area before and after the remote mapping process. We managed to digitize around 90% of the infrastructure data (buildings and roads).
Image 1.1. Before remote digitization
Image 1.2. Before remote digitization
After all the general buildings in the residential area were remotely mapped, we conducted a field survey to map the critical infrastructure in the flood affected area. We used OsmAnd, an Android-based application, and field papers to mark waypoints, take photos, and record the GPS tracks.
Figure 2. Screenshot of OsmAnd
Image 3. Field paper of Nong Hoi
We collected information on critical infrastructure that are important for evacuation during a disaster, such as locations of health facilities, schools, places of worship, emergency shelters, public speaker poles, and drain manholes. We then uploaded this information as gpx data onto OSM.
Image 4. Data input to OSM via Java OpenStreetMap (JOSM)
We downloaded the compiled data from OSM using the HOT Export Tool (https://export.hotosm.org), and produced a map of the Nong Hoi neighbourhood using QGIS.
Image 5. Final product: map of Nong Hoi neighbourhood on OSM
Based on the final map, we discovered that the location of the evacuation centres are neither safe and nor appropriate. One is located under a flyover, while another one is located in a public cemetery. Both of them do not have proper shelter and sanitation facilities. We also discovered that there is no visible day care centre nearby. Day cares are important for post-disaster recovery as they allow for duel income families, where both parents are able to work and recover the financial loss.
On the plus side, there are plenty of health facilities around the neighbourhood. The community centre is also close to residents, and is accessible via major roads
Click here details (HOT activity report)