Global Drought Monitoring Service through the GEOSS Architecture ...

Architectural Implementation Pilot, Phase 3 Version: 2.0
Global Drought Monitoring and European Drought
Observatory-Water SBA Engineering Report
Date: 11/Feb/2011
Architecture (Nagai 2010)
Figure 13 (Nagai 2010)
3.4.1 Adding Advanced Search and Discovery using Semantics
The AIP-3 video 23 , “Drought—European” includes a walkthrough demonstrations, in
which users select scientific terms (or “concepts”) and, secondly, the geographic region or spatial
domain which is defined within a bounding box. This reflects the division into lexicographic and
geographic content which has been cited in Section 3.5. The purpose of the semantic enrichment
was to supplement keyword searches, such as used on Google, by adding search capability that
could search through concepts; this is tantamount to adding “Semantics.” In other words, one is
not searching for “drought” as a keyword; one is searching for “drought” as a concept, combined
with search functionality that allows the user to select broader or narrower searches within the
drought field or within allied fields. For example, “water” is a concept which can be broken up
into underlying processes of “evapotranspiration,” “streamflow,” “precipitation,” “soil
moisture,” “snow cover,” and “groundwater.” The stores of water are a subset or part of water,
and this class structure is affected in the arrangement of the terms within the semantic network.
Datasets can be registered to each of these terms, so that queries of “hydrologic drought
indicators” reveal “groundwater” data, “streamflow” data, such as baseflow, and other water
budget information for a selected area. The EuroGEOSS discovery broker has the capability to
access the GI-Cat registered datasets on groundwater, river discharge, water usage, and other
data. Search-by-concept is intended to not only improve the “hit-or-miss” success rate of recall
of datasets through keyword searches alone but also reduce the high amounts of irrelevant
returned results in keyword searches.
Figure 8 is a screen capture of the search interface in the AIP-3 “Drought—European”
23 http://www.ogcnetwork.net/pub/ogcnetwork/GEOSS/AIP3/pages/Demo.html
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