Christophe Lienert

An interactive, web-based, real-time hydrological map information system

Abstract Hydrologists responsible for flood management need real-time data in order to manage imminent or ongoing floods. In this paper, innovative methods for accessing hydrological data and their spatial visualization are introduced. A multitude of relevant real-time, forecast and historical information is provided in a single, self-updating hydrological map information system. The system consists of a central database and a cartographic user interface and provides harmonized and filtered data in the form of interactive, customizable maps. Maps may also be cross-referenced with historical maps or may be animated for improved comprehension and decision making. Emphasis is placed on the development of the hydrological real-time database that manages large amounts of spatial, temporal and attributive data. The paper focuses on the cartographic user interface, its functionality and the resulting interactive hydrological maps. Citation Lienert, C., Weingartner, R. & Hurni, L. (2011) An interactive, web-based, real-time hydrological map information system. Hydrol. Sci. J. 56(1), 1–16

Current trends in vector-based Internet mapping: A technical review

Possibilities and limitations of Internet cartography software largely depend on the pace set by the software industry. The variety of commercial and non-commercial software caters for the needs of a continuously growing mapping community, including both professional and amateur cartographers. This chapter provides an overview of state-of-the-art technologies for vector-based Web-mapping as of the beginning of 2011. Both proprietary and open format technologies are discussed for vector data rendering in browsers, highlighting their advantages and disadvantages. The discussed technologies are Adobe Flash, Microsoft Silverlight, Scalable Vector Graphics (SVG), JavaFX, Canvas, and WebGL. The chapter also discusses client and server side frameworks which provide Application Programming Interfaces (APIs) for creating custom interactive maps, mainly by overlaying raster images with vector data.

Real-Time Visualization in Operational Hydrology through Web-based Cartography

Early warning and monitoring activities in the field of natural hazard management are crucial in order to limit damage to life and property from extreme natural events. Decision makers in these fields, such as operational hydrologists, must be enabled to quickly and comprehensively assess an on-going situation, examine its details, and then take further actions based on the most current information available. The cartographic challenge is to deliver automated, real-time visualizations from distributed raw measurement data while applying sound cartographic rules and standards. In this research, a web-based, cartographic, real-time information system is presented. True real-time data of Swiss hydro-meteorological measuring networks were used, and a prototype application was tested that integrates the acquisition, processing, and visualizations in different ways, depending on the chosen timeframe and level of detail. Besides monitoring visualizations, data are retraceable using visualizations that clearly stress the course of a hydrological event and the datas spatio-temporal character. Further visualizations and functionalities are provided that allow for relating real-time data to a broader historical context, facilitating learning from former experiences. Data for past events are immediately retrievable from a data archive, then classified and visualized for comparisons.

Monitoring and Comparing: A Cartographic Web Application for Real-time Visualization of Hydrological Data

As decision support in flood warning, experts within crisis management groups need readily available real-time data, and real-time visualization derived from them. Up until now, work steps including acquisition, harmonization, storage, processing, visualization and archiving of data have been accomplished manually or semi-automated. In a cartographic real-time application, these worksteps have to be achieved online and error-free. The presented web application and the generated real-time visualization products are based on a viable data model which is extendable by additional measurement or model ouput data. By means of a graphical user interface, users may overview the most current hydrological situation in the form of automatically processed real-time maps. In addition, these maps may be interactively compiled, depending on users’ needs, on different levels of detail, and in various thematic combinations. In order to classify the most current hydrological situation in the historical context, i.e., to eventually learn from the past, the application also allows to easily create visualizations of past flood events. Data from a long-term, high-resolution archive undergo the same cartographic rules and abstraction as real-time data for the purpose of direct comparisons.