A researcher, Roya Olyazadeh, from University of Lausanne, developed a prototype web application and an offline mobile version for data collection on the impacts of natural hazards in Nepal, such as damaged infrastructure, landslide or flooding events. This collected information can be made available to and used by the responsible authorities and the public for further analysis and visualization. This application is designed as a low-cost, rapid and participatory method for recording of impacts happened due to hazard events and includes geolocation, map visualization, mapping of events with image captures and adding comments or feedback for public participation. Different user levels can be defined for data access and information. The objectives of this work are to provide:
- a mobile application with advanced geospatial visualization;
- a service for easy data collection and storage of events information;
- a centralized data storage accessible by different platforms (smartphones and standard web browsers);
- an active participation method in event mapping and storage of information.
Based on the recent visit to Nepal, an offline mobile version is made available to address the lack of internet accessibility in rural areas. This version also includes an interactive, offline map with background satellites image to enhance the visibility and mapping of landslides in the area. After the geolocation, the user can start mapping and save data into a text file that can be easily uploaded to the server whenever internet connection is available. All the events and records can be visualized within a map interface by an administrator and made available to the public after the approval. This prototype specifically targeted at conducting an assessment of landslides within a predetermined area to assess land use characteristics such as roads, forest areas and rivers.
A two-day field work was carried out to apply and test the application. The selected field area is close to Pokhara where many landslides has been activated or reactivated after the last monsoon. During the field trip (Figure 1), more than 60 landslides in this area have been recorded. Figure 2 shows three landslides in this area. Some of the landslides were close to the road and mapping was easier, however, some were located distantly and accessibility to the area was difficult. For those that were located in distance, a satellite image map has been preloaded into the offline application to assist the mapping. Figure 3 illustrates how mapping on different landslides can be done. The mapping process is easy and different features such as polygons, points or lines can be drawn. The user can then save these features as one event and define additional characteristics such as land use, damage, trigger, possibility of hazard and so on. Figure 4 and 5 show data added to the online version with a possibility of editing them.
Credit and source information: We would like to mention our thanks to Ms. Roya Olyazadeh (@roya2543, University of Lausanne) for providing data, information and images related to the development of the application and her recent field trip in Nepal.
Figure 1 Landslide mapping by road and in rural areas by a group of researchers (source: Roya Olyazadeh)
Figure 2 Some of the landslides mapped in the offline application (source: Roya Olyazadeh)
Figure 3 Offline mapping of two different landslides within the application in an android tablet (source: Roya Olyazadeh)
Figure 4 Uploading offline data into an online application and edition of an event if needed (source: Roya Olyazadeh)
Figure 5 All the events with their features loaded in online version of the application, showing events as cluster points and landslides in red polygons (source: Roya Olyazadeh)