Electronic Watershed: Semantic GIS, Ontologies, and Organizing Knowledge

Tom Van Buren

Abstract

Drawing on the World Wide Web Consortium recommendations and Semantic Web activities where "information is given well-defined meaning and better enabling computers and people to work in cooperation," the City of Seattle's Cedar River Municipal Watershed is developing a "semantic GIS" that will lead our GIS to its full potential. Building upon standard eXtensible markup language (XML) and Resource Description Framework (RDF) technologies and tools developed by the Apache Software Foundation and Esri, we are providing an information service of watershed content for all users - like a good library - multivariate, multitemporal, and high resolution.

 


Introduction

Located 35 miles southeast of Seattle and larger than the City itself, the Cedar River Municipal Watershed supplies more than two-thirds of the region’s drinking water. Comprising two-thirds of the entire Cedar River Basin, this 91,465 acre natural area supports a wide diversity of plants and animals and several major ecosystems. The Watershed Information Technology Unit (WIT) enables ready access to information for the Watershed Management. Much of work for WIT comes from the Cedar River Habitat Conservation Plan (HCP), a 50-year, ecosystem-based plan that will cost the City of Seattle ratepayers approximately $90 million to implement. It ensures the City of Seattle's drinking water supply and protects and restores habitats of 83 species of fish and wildlife that may be affected by water supply and hydroelectric operations on the Cedar River. The plan includes land and forest management in the municipal watershed, mitigation for the blockage to anadromous salmon and trout at the City's drinking water intake, regulation of stream flows in the Cedar River, and research and monitoring to support conservation and mitigation measures.

 WIT's vision: The Watershed Management Division will be web-enabled, using information science and technologies to electronically gather, analyze, and retrieve watershed information for all of our stakeholders. Our systems will be easily modified and quickly tailored to our changing needs. We will provide viable, cost effective, content management solutions for the division. Web services will offer fresh stimulating content and dynamic access to structured information.

WIT's action steps: Adopt best practices in GIS, web technologies, and object oriented programming. Build an information framework - "data you can trust" -- and serve the best available data for the City of Seattle, certified, standardized, and described according to common standards. Focus on getting the right information to the right people at the right time and providing them with the tools to use the information. Develop an interlocking set of formal techniques in which business models, data models, and process models are built up in a comprehensive knowledge base and are used to create and maintain information systems. Build an open standards, vendor neutral, platform agonistic foundation for web services and an electronic library of information about watershed management. Writing metadata is a vital part of the framework.

 

What's the problem?

"Biological information about biodiversity and ecosystems is among the most complex scientific data to manage electronically, yet it is vitally important that we do so. There are intellectual challenges in the area of biodiversity information analysis, synthesis, presentation, validation and long term storage that require considerable information science and computer science research and infrastructure "—Panel on Biodiversity and Ecosystems, President’s Committee of Advisors on Science and Technology (PCAST, 1998)

Currently much information at the Watershed Management Division is stored in basements, closets, file cabinets, PC disk drives, or in our heads. Typically the information is in a proprietary format, unstructured, undocumented, and difficult to use in decision-making, analysis, or presentations. Like a good library, the Division has a wealth of information; unlike a library, we neither have a catalogue to understand the content nor a mechanism to retrieve it.

Ecosystems are complex systems. Managing ecological and environmental data is complex. Making available information accessible, and capturing new information is a challenge. Managing a habitat conservation plan and determining where to intervene in the watershed (where to spend money) is not easy. Ecosystem management is evolutionary, there is a great deal of uncertainty as to outcomes, and decisions are made with limited information.

 

Why do we care?

"The science of ecology urgently requires a concerted effort to develop informatics and collaboratory framework to provide access to information from the many disciplines contributing to our understanding of biocomplexity in the context of global ecosystems." (KNB, 1998)

If we don't capture information in a meaningful structure it'll be lost forever. Sharing information is vital in learning from others, adapting management, tracking of our work, and incorporating the results in future decisions. The City of Seattle water rate payers have committed $90 Million to the Habitat Conservation Plan and we need to spend the money thoughtfully and prove the worth of the results of our work.

WIT's solution

In order to capture what is learned we need to build an information service to systematically gather, analyze and retrieve resources to help us "design, implement, monitor, learn, and adjust" (Franklin, 1997). We engage in the watershed in many different ways. From using information services in the office, meeting face to face with interdisciplinary team members, to collecting new data in the field. Each way we engage in this world involves a certain conceptualization, or "a system of concepts and categorizations which divide up [our] universe of discourse into objects, processes, and relations in different sorts of ways." (Smith, 2001)

Build an Ontology

Ontologies provide a shared and common understanding of a domain that can be communicated between people and heterogeneous and widely spread application systems (Fensel, 2001). WIT must find out how things are being done in the field and create categories and vocabularies based on how our world of ecosystem management at the Watershed Management Division is actually operating. We can not ignore the "real world of flesh-and-blood objects in which we all live" (Smith, 2001).

Resource Description Framework (RDF) is a general purpose language for representing information or describing resources on the World Wide Web (Manola, 2002). RDF works with metadata and its specifications provide a lightweight ontology system to support the exchange of knowledge on the web (W3C, 1999).

"RDF can be used in a variety of application areas; for example: in resource discovery to provide better search engine capabilities, in cataloging for describing the content and content relationships available at a particular Web site, page, or digital library, by intelligent software agents to facilitate knowledge sharing and exchange." (Lassila, 1999)

Build Web Services

Web Services are standards-based, best computing practices to efficiently and cost effectively share resources among disparate data and software applications and to provide seamless and rapid access to information across the organization. Web services depend on a structured catalogue that describes data and build on the standard protocols of XML and HTTP.

Build Metadata

WIT must build an information system that makes it easy to collect metadata. "Metadata are data which serve to describe data sets, databases, or information products (such as a maps or technical reports) by documenting such things as subject matter; how, where, and when the data were collected; accuracy of the data; and availability and distribution information. " (NSDI, 1999). "Metadata should form a strong basis for a web of machine understandable information about anything: about the people, things, concepts and ideas." (Berners-Lee, 1997)

Adopt open standards

The Extensible Markup Language (XML) is the universal format for structured documents and data and the XML family of technologies make data accessible via a web browser. Of particular interest to WIT is the Ecology Markup Language (EML) an XML schema of ecological metadata. EML draws upon many emerging standards. Dublin Core Metadata Initiative, the Content Standard for Digital Geospatial Metadata (CSDGM from the US geological Survey's Federal Geographic Data Committee (FGDC)), the Biological Profile of the CSDGM (from the National Biological Information Infrastructure), the International Standards Organization's Geographic Information Standard (ISO 19115), the ISO 8601 Date and Time Standard, the OpenGIS Consortium's Geography Markup Language (GML), the Scientific, Technical, and Medical Markup Language (STMML), and the Extensible Scientific Interchange Language (XSIL).

Define the work

Develop a database enabled web site that will permit archiving documents and maps, enable searches, include a high resolution image server and installation of an internet map server, enable interactive spatial data queries and access, develop interactive reporting tools, enhance existing shed map, and support streaming video and audio. Build a watershed portal to current and historic content. Detail prescriptions using Oracle and extensible markup language (XML) technology and resource description frameworks (RDF). Develop web services pursuant to Web Services Description Language. Use embedded markup language to describe our data in way that is meaningful to our stakeholders and that reflects the nature of the data.

The database and web site should enable three types of requests and queries: Gather, Analyze, and Retrieve on the following resources:

 

Assumptions

References

Lassila, 1999 http://www.w3.org/TR/1999/REC-rdf-syntax-19990222/

Cocoon, 2002 http://xml.apache.org/cocoon/introduction.html

Manola, 2002, http://www.w3.org/TR/2002/WD-rdf-primer-20020319/

Berners-Lee 1997 http://www.w3.org/DesignIssues/Metadata

Open GIS Consortium http://www.opengis.org/

World Wide Web Consortium http://www.w3.org/

Geography Markup Language http://www.opengis.net/gml/00-029/GML.html

Dublin Corp Metadata Initiative http://dublincore.org/

Resource Description Format http://www.w3.org/RDF

The Apache Software Foundation: http://www.apache.org/

Organization for the Advancement of Structured Information Standards http://www.oasis-open.org/

Rational software development http://www.rational.com/

Object Management Group Model Driven Architecture http://www.omg.org/

HJ Andrews Experimental Forest: http://www.fsl.orst.edu/lter/

Knowledge Network for Biocomplexity KNB: http://knb.ecoinformatics.org/

http://www.nceas.ucsb.edu/nceas-web/projects/2840/proposal/kdiproposal1999-public.pdf

Dynamic Systems Design Methodology: http://www.dsdm.org/en/default.asp

 

Fensel, D, 2001, Ontologies: A Silver Bullet for Knowledge Management and Electronic Commerce, Berlin: Springer-Verlag

Franklin, J, 1997, "Ecosystem Management: An Overview", in Boyce, M, Haney A eds, Ecosystem Management, New Haven: Yale University Press.

Smith, B. and Mark, D, 2001, "Geographical categories: an ontological investigation", International Journal of Geographical Information Science, volume 15, number 7, London: Taylor Francis

NSDI, 1999, The FGDC Biological Metadata Profile, http://biology.usgs.gov/fgdc.bio/

PCAST. 1998. Teaming with Life: Investing in Science to Understand and Use America's Living Capital. President's Committee of Advisors on Science and Technology: Panel on Biodiversity and Ecosystems.

 


Author Information

Tom Van Buren

Watershed Management Division, Resource Management Branch
Seattle Public Utilities, City of Seattle
19901 Cedar Falls Road
North Bend, WA 98045
Phone (206) 386 4212
Fax (206) 615 1923
Email
tom.vanburen@ci.seattle.wa.us