1,720,968 research outputs found
WebGis Architectures for Emergency Response
No full textIn the era of information internet is the main source from which to find anything. The story of internet is recent and brief, about 20 years, during which it has evolved continuously and quickly. The information given in the first years was flat like pure text or documents but in the last 10 years the type of information shared has changed, moving to other dimensions from the flat page. Now we can experience videos, music and even maps. The concept of attaching geographic information to the information itself has spread on almost every site. Maps are everywhere because the question "where does this come from?" has assumed the same importance as the "what". Georeferencing and managing spatial information is not the same as managing non spatial information because there is an increase in complexity due to the fact that geographic information is not absolute. In the world there are thousands of "spatial reference systems" (srs) and different standards on how to share spatial data. Whoever hosts spatial data must allow the gathering of data in different formats and different "srs". On the other hand there is the fact that with spatial data we can perform spatial analysis such as distance calculations, routing or proximity. Many services which deal with spatial data even offer some additional services such as Google Maps. In many cases the web spatial information is gaining much importance, paper maps have always been used to plan the environment and the actions on it, but digital mapping allows more degrees of freedom granting the ability to customize what we want and how we want it presented wherever we are. The case of humanitarian emergencies is the core example about how the management of information and the usage of it are totally displaced. Whoever manages and keeps spatial data can be in a HQ office and people in the field can use information without worrying about getting it physically. The only thing needed is an internet link, which now is granted by satellite communication even if on the ground there is lack of infrastructures. This PhD thesis has been developed in the framework of the collaboration between Information Technology for Humanitarian Assistance, Cooperation and Action (ITHACA), a non profit association founded by the Politecnico di Torino and the Istituto Superiore per i Sistemi Territoriali e l'Innovazione (SITI) and the World Food Programme (WFP). The collaboration with the WFP characterizes the research projects in the field of humanitarian emergencies and the goal of the present thesis. One of the core things that determine a good emergency response is data availability. This term means both immediate availability after the event and quality availability, having the most up to date and precise data. To meet the challenge of rapid WebGis development and data sharing in case of emergency, this work has focused on the development of an architecture composed by Open Source tools integrated and tuned to allow the building of WebGis and web applications in short time but maintaining an high level of customization. The panorama in the geographic Open Source community is populated by several tools dedicated to specific tasks like data publishing, data management or user interface; however these projects have always been independent from each other without a common design able to harmonize the efforts in one single tool. The idea is to have a unique server architecture composed of data publishing and management systems able to output data in different ways based on the web HTTP protocol and respecting international standards. Web applications should act as custom views on the architecture and web services should allow access to data regardless of the requesting source. The development process has involved deep research into basic informatic tools and operating systems as well as high level programming languages. Following several web applications, an environment able to manage different technologies and data sources has been built. The goal is to test the proposed solution during real case studies in order to exploit usability, stability as well as effectiveness during emergenc
RAPID WEBGIS DEVELOPMENT FOR EMERGENCY MANAGEMENT
Full text linkThe use of spatial data during emergency response and management helps to make faster and better decisions. Moreover spatial data should be as much updated as possible and easy to access. To face the challenge of rapid and updated data sharing the most efficient solution is largely considered the use of internet where the field of web mapping is constantly evolving. ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action) is a non profit association founded by Politecnico di Torino and SITI (Higher Institute for the Environmental Systems) as a joint project with the WFP (World Food Programme). The collaboration with the WFP drives some projects related to Early Warning Systems (i.e. flood and drought monitoring) and Early Impact Systems (e.g. rapid mapping and assessment through remote sensing systems). The Web GIS team has built and is continuously improving a complex architecture based entirely on Open Source tools. This architecture is composed by three main areas: the database environment, the server side logic and the client side logic. Each of them is implemented respecting the MCV (Model Controller View) pattern which means the separation of the different logic layers (database interaction, business logic and presentation). The MCV architecture allows to easily and fast build a Web GIS application for data viewing and exploration. In case of emergency data publication can be performed almost immediately as soon as data production is completed. The server side system is based on Python language and Django web development framework, while the client side on OpenLayers, GeoExt and Ext.js that manage data retrieval and user interface. The MCV pattern applied to javascript allows to keep the interface generation and data retrieval logic separated from the general application configuration, thus the server side environment can take care of the generation of the configuration file. The web application building process is data driven and can be considered as a view of the current architecture composed by data and data interaction tools. Once completely automated, the Web GIS application building process can be performed directly by the final user, that can customize data layers and controls to interact with the
A public platform for geospatial data sharing for disaster risk management
No full textSeveral studies have been conducted in Africa to assist local governments in addressing the risk situation related to natural hazards. Geospatial data containing information on vulnerability, impacts, climate change, disaster risk reduction is usually part of the output of such studies and is valuable to national and international organizations to reduce the risks and mitigate the impacts of disasters. Nevertheless this data isn't efficiently widely distributed and often resides in remote storage solutions hardly reachable. Spatial Data Infrastructures are technical solutions capable to solve this issue, by storing geospatial data and making them widely available through the internet. Among these solutions, GeoNode, an open source online platform for geospatial data sharing, has been developed in recent years. GeoNode is a platform for the management and publication of geospatial data. It brings together mature and stable open-source software projects under a consistent and easy-to-use interface allowing users, with little training, to quickly and easily share data and create interactive maps. GeoNode data management tools allow for integrated creation of data, metadata, and map visualizations. Each dataset in the system can be shared publicly or restricted to allow access to only specific users. Social features like user profiles and commenting and rating systems allow for the development of communities around each platform to facilitate the use, management, and quality control of the data the GeoNode instance contains (geonode.org). This paper presents a case study scenario of setting up a Web platform based on GeoNode. It is a public platform called MASDAP and promoted by the Government of Malawi in order to support development of the country and build resilience against natural disasters. A substantial amount of geospatial data has already been collected about hydrogeological risk, as well as several other-disasters related information. Moreover this platform will help to ensure that the data created by a number of past or ongoing projects is maintained and that this information remains accessible and useful. An Integrated Flood Risk Management Plan for a river basin has already been included in the platform and other data from future disaster risk management projects will be added as wel
Ithaca worldwide flood alert system: the web framework
No full textInformation Technology for Humanitarian Assistance, Cooperation, and Action (ITHACA) is developing a worldwide early warning system for flood events (Albanese et al. 2008). The system collects rainfall data from NASA Tropical Rainfall Monitoring Mission website every 3 h, processes them, and compares them to historical data series to detect an alert level for each basin. Watershed layer of HYDRO1k, developed at the US Geological Survey's Centre for Earth Resources Observation and Sciences, is constituted by a territorial subdivision at different levels, increasing details from levels 1 to 6; watershed at maximum detail (level-6 basin) are used for the system. A grid-computing approach is adopted to face the heavy computational load while a web-fruition framework is planned to give the widest access to the output the system produces. The user interface shows ongoing events on a map, where it is also possible to add other feeds (i.e., by Global Disaster Alert and Coordination System). The user can zoom to the alerted countries by an interactive list or have additional information on the event and possibly an estimate of the affected population shown. The framework is based on pure Free and Open Source Software (FOSS) products and common standards, according to ITHACA internal directives and following United Nations Geographic Information Working Group directives that encourage interoperability and FOSS tools adoption. The framework is a development of ITHACA infrastructure for web GIS applications; it is based on Model Controller View (MCV) architectural pattern that makes it possible to isolate the logic of the application from the interface. In this way, a change in one of the two parts does not affect the other making maintenance easier in the long term. From this point of view a controller collects, the model manipulates application data, and the view presents results to the user. Here, a Python-based MCV framework named Django is adopted; interfaces are built using JavaScript classes which some FOSS projects make available. Some OpenLayers classes are modified and combined with Ext and GeoExt libraries to increase the interaction the user can have with the interface. Data are symbolized using common Open Geospatial Consortium Styled Layer Descriptor standard. Caching mechanism for Web Mapping Service base layers is adopte
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
