Global Drought Monitoring Service through the GEOSS Architecture ...

More documents

Recommendations

Info

Architectural Implementation Pilot, Phase 3 Version: 2.0 Global Drought Monitoring and European Drought Observatory-Water SBA Engineering Report Date: 11/Feb/2011 However, there are good reasons for embarking upon a bottom-up system. A global top down system can imply that drought is present within a local area, although the local area might be drought-free due to availability of secondary sources of water such as groundwater. Having participation of members who are familiar with local conditions on the ground is invaluable in setting up a global drought monitoring system. A global network of national hydrometeorological service and ministry-based drought experts can provide the expertise to carry out retrospective validations of drought forecasts, along with fine tuning of the drought forecasting system, part of the life cycle by which “experimental” (research stage product) becomes “operational.” Drought monitoring and forecasting is intended for applications. For example soil moisture monitoring and forecasting can support farmers’ activities. Since the size of farms may vary, a drought early warning system is best applied at local scales. This means that a coarsescale system may not be very valuable for providing decision support. A drill down system is built upon a combined bottom up-top down system, in which the highest resolution drought maps of the system, i.e., those at river basin scale or national scale can be used for drought early warning applications or used for agricultural support. 3.2.3 Soil Moisture and Agricultural Drought Monitoring Requirement Given the importance of soil moisture in agricultural drought monitoring, and the importance of agriculture in the world food problem, remote sensing-based and modeled-based soil moisture should be utilized within the system. 3.2.4 Republication of information to help decision makers facilitate drought decision making Integrating together multiple disciplinary and cross-disciplinary information, such as drought severity information and agricultural production data, require different informatics strategies to carry out such integration. While layers can be added together and removed within a Geographic Information System (GIS), more sophisticated tools are required in order to assemble all of the information in a form that can be immediately used for decision making. As noted by Lemon et. al (2010): “The ‘Discover, Display, and Download’ Use Case has misled us. No one simply wants to find, look at, and collect data. To the contrary, they all want to do something with the data: subject it to some analysis, make a map, or prepare a basis for making rapid decisions.” Search and discovery alone will not make GEOSS a viable system, valuable to end users: its information has to be repackaged into a user-friendly form that provides application knowledge and accelerates decision making. 3.2.5 Hydrologic Drought Monitoring for Semi-Arid Areas and Meeting Hydrologic Drought User Requirement through Semantics The hydrologic drought indicator user requirement creates a need for assembling information on water budget components, such as groundwater, streamflow, precipitation, soil water, snow cover, etc. The sheer volume of information, particularly if assembled over large Page 32
Architectural Implementation Pilot, Phase 3 Version: 2.0 Global Drought Monitoring and European Drought Observatory-Water SBA Engineering Report Date: 11/Feb/2011 segments of the globe, will require some integrative technology in order to accommodate the utter complexity of multiple languages, multiple scientific terms within different languages, differences in place names to describe geographic entities, and multiple variable names within database schema. These are the requirements for a semantic-based information system: datasets and records have to be registered at the level of water budget components, i.e., stores of groundwater, river water elevation, precipitation, etc, to meet the requirements for hydrologic drought monitoring. This also means, conversely, that a semantic ontology has to include these concepts, as well, within the water ontology, for the purposes of organizing information. This level of detail is a critical requirement. Several possible methodologies for achieving multidisciplinary interoperability take advantage of the possible integrative power of Semantic Web technologies, developed by Tim Berners-Lee (Berners-Lee, Hendler, Lassila 2001; Yu(2007). What, simply put, does the semantic web do? It tries to lift the burden off the user of having to process huge amounts of information by automating (and making machine readable) the collection and processing of information, so that the processing burden may be shifted from the user to the machine. Semantic web techniques improve irretrievability of the correct document or resource or dataset by providing semantic annotation through Resource Description Framework (RDF) or RDFS, perhaps combined with an ontology which provides the structural arrangement of the resources in context with one another, along with possibly including some simplified artificial intelligence application for sorting or selection. Semantics can be directly employed within the decision support services developed by GEO, i.e., within the software applications and processing of data. For example, SEAMLESS links together application modules (such as used in Delft- Flooding Early Warning System or FEWS) and component-based applications that can be orchestrated into a workflow run over a framework, in this case, OpenMI (Rizolli, et. al 2007). Another use of semantics is the more traditional search and discovery role. This use case of semantics is what has been explored within this session of AIP-3, as a test case project within the European Union among the architects of the EuroGEOSS discovery broker, the AIP-3 Semantics Working Group, the European Drought Observatory, and the AIP-3 Water and Drought Working Group. 3.3 Developing an Architectural Diagram for the GEO Global Drought Monitoring Service Figure 6, derived from the Australia Water Resources Information System, illustrates some of the components that are prerequisites for the Global Drought Monitor Portal (GDMP). The “system architecture” is a diagram of the applications and the tools, combined with the enabling framework at the component level. Figure 6 shows the bottom rung of data entering through the observing system, as, respectively, “Numeric data” (as in soil moisture generated by the VIC and LISFlood models), or satellite source “Sensor output” originating from space-based scatterometer soil moisture data. The upper tier illustrates in schematic boxes some additional components, the Open Geospatial Consortium (OGC) geospatial Web Mapping Services (WMS) exchange of drought maps. The exchange of drought maps among the European Drought Page 33
Page 1 and 2: Global Drought Monitoring Service t
Page 3 and 4: Architectural Implementation Pilot,
Page 31: Architectural Implementation Pilot,

Global Drought Monitoring Service through the GEOSS Architecture ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?