by Cristina Rosales Sánchez
The objective of the present research project is the design of a software architecture for a web-based platform that uses GIS technologies to function as a tool for decision support system (DSS) in case of disasters. When disaster arises, the unpredictability and dynamics of the situation makes the phase of response challenging, hindering the decision-making processes. The possibility to collect information from different sources, official (e.g. sensor networks monitoring environmental variables, emergency resources availability and location) and non-official (volunteered geographic information), in a one-stop platform allows a better understanding of the situation and supports the decision making of the different actors involved (i.e. crisis managers, emergency response organizations, general citizens).
Following the cycle of user-centred design (UCD), the study first identifies the user requirements of a tool for DSS in case of disasters. Literature review on related projects generates a background of the user needs tackled by the different initiatives. Then, Personas method and generation of scenarios helps to get a more thorough and concise knowledge of the user requirements. These requirements together with the analysis on suitable software architectures and components are the base of the software architecture design of the aimed tool for DSS in case of disasters. The last step in the process is the evaluation of that software architecture design, what is achieved by two approaches: (1) a functional evaluation to test the design feasibility by developing a prototype to tackle selected functionalities (derived from the user requirements); and (2) assessing the usability of the designed tool by testing a mock-up version of a smartphone app based on the proposed design by the Personas using the think-aloud method. This way the study goes once through the cycle of UCD, developing a solution that addresses the identified user requirements.
Going through the method the identified user requirements of a tool for DSS in case of disasters are related with the notification of alerts, information on the spatio-temporal evolution of the disaster, suggestion on routes to reach safer destinations, and information about the status of users’ families and friends. The solution proposed to address these requirements is a Geoweb, which exploiting the advantages of the technologies Web 2.0, allows the integration of official and non-official data sources, and also the visualization and analysis of the information that is required for the potential users. Based on a client-server structure and aiming the interoperability between the diverse data and also between the multiple actors, the Geoweb design is formed by open source components and the use of the recognized OGC protocols. Basically the design components are: PostgreSQL/PostGIS as the spatial object-relational database management system for the collection and integration of the multi-source information; GeoServer as application server to load, publish and share the information by internet; and OpenLayers as the mapping application.
The feasibility of the Geoweb is tested for the routing and flood mapping functionalities by developing a prototype following the designed software architecture with open source components. Integrating information about the flood status and information collected by citizens to the road network provides different alternatives at the routing calculation results, supporting the users’ decision-making process. Besides the use of the think-aloud method with the defined Personas reveals that the routing functionality and the flood evolution visualization are the best considered functionalities of the system. In addition, the combination with other information like shelters location or citizens’ reports enlarge the effectiveness of the information offered by the tool. Despite of that, the messaging functionally was not found helpful but confusing, maybe due to the mock-up design. Moreover, even though the integration of multi-source information seems to be gladly received by most of participants, it can also generate more difficulties in some occasions when different sources point to different information.
This study can be used as a guideline and framework for further developments of tools for DSS in case of disasters, even though further research may address issues such as the integration of the information and the assimilation of big data volumes from citizens.
Keywords: FOSS4G, crisis management, VGI, Geoweb, Web 2.0.