Docstoc

Marine spatial data infrastructure

Document Sample
Marine spatial data infrastructure Powered By Docstoc
					                                      Marine spatial data infrastructure

                                                         by Laurent Drapeau, IRD


The world’s oceans are fundamental to ecosystem processes that influence natural and human environments. The need for
global systems of ocean observations, to enable effective and sustainable management of marine and coastal ecosystems,
is now widely acknowledged. The Reykjavik Declaration on Responsible Fisheries in the Marine Ecosystem emphasises
that “building or enhancing systematic monitoring of natural variability and its relations to ecosystem productivity” is of
great importance.


Providing an integrated service to             multiple purposes. Some benefits of           Interoperability can only be achieved
intermediate users and policy makers in        implementing SDI are the improved             through extensive used of international
support of efficient offshore activities,      accessibility to data and interoperability    standards. They specify regulations for
environmental       management,        and     between datasets. As quoted in the SDI        data access, content, and exchange. The
sustainable use of marine resources            Cookbook from the Global Spatial Data         International Standards Organisation
is therefore a key element to improve          Infrastructure Technical Working Group        Technical Committee 211 (ISO TC/211)
management and protection of coastal and       (www.gsdi.org), without a consistent SDI,     developed 40 geographic information
marine ecosystems. This requires sustained     there are inefficiencies and lost             standards. The International Hydrographic
and comprehensive observations to              opportunities in the use of geographic        Organisation (IHO) and the International
accurately describe and assess the present                                                   Hydrographic Bureau developed a
                                               information to solve problems.
conditions and trends of ecosystem states,                                                   transfer standard for digital hydrographic
as well as the pressures and impacts upon      The concept of marine and coastal SDI is      data and are developing other standards
them to promote sustainability.                recent but the need for better management     for marine data. These, haven’t reached
                                               through enhanced access to spatial            the completeness level of the ISO TC/211
By providing common geographic context
                                               data is well documented. A distributed,       standards.
to multidisciplinary approaches, spatial
                                               federated network for marine science
information allows better understanding                                                      The ISO 19115:2003 defines the
                                               data and information can be structured in
of ecosystems and therefore contributes                                                      schema for geographic information and
                                               order to act as a development structure,
to improved management policies. As a                                                        services. It provides information about
                                               and forerunner for a regional monitoring
result, geographic information is a critical                                                 identification, extent, quality, spatial and
                                               system in the GEOSS (Global Earth
element for decision making at local,                                                        temporal schema, spatial reference, and
                                               Observation System of Systems) context.
regional, and global levels. Observation                                                     distribution constraints. It is applicable to
systems and geo-datasets exist and             This marine SDI provides data search          cataloguing, clearinghouse activities, and
provide information for a wide spectrum        through metadata catalogues (ISO-             the full description of datasets.
of disciplines, but they are often not         TC21), and the means to discover,
                                                                                             Implementation of these standards is
integrated into a coherent whole.              visualise, and evaluate datasets with
                                                                                             achieved with the Extensible Markup
                                               web mapping (WMS, WCS, WMS,
An extensive amount of data is                                                               Language (XML). XML provides a common
                                               WPS) capabilities. This federated and         format to store data. At present, several
structured for the marine and coastal
                                               collaborative      network    can   benefit   projects are involved in the establishment
environments, but it is often unavailable
                                               existing regional GIS developments that       of a marine specific XML such as the
or, when available not interoperable,
                                               structured numerous and heterogeneous         Australian Oceanographic Data Centre
and therefore difficult to exploit in
                                               sources of spatial data from a variety of     (AODC) and a “Marine XML consortium”
broader contexts. Data collected on a
                                               projects and disciplines such as physical     was created by the International Oceans
project-basis are rarely shared between
projects. Fragmentation, availability gaps,    oceanography, remote sensing imagery,         Commission (IOC). It promotes the
duplication,   identification   problems,      fisheries statistics, ecology, coastal and    development of a marine XML international
access and usability are common issues.        inshore management.                           standard.

In response, the spatial data infrastructure   The main objectives of such an SDI are:       Metadata standards for geospatial
(SDI) approach has been developed to           •	    Effective searching and discovery       datasets are the building blocks of an
create environments that enable users                tools.                                  SDI, but making marine data discoverable
to access and retrieve spatial datasets        •	    One-stop	shop	for	access.               requires distributed geospatial data
in an easy and intuitive way. They             •	    Optimised	data	access	and	re-use.       catalogues. Implementation of such
ease the use and sharing of spatial            •	    Interoperability	between	               distributed “catalogue nodes” is an
information and services to support                  stakeholders, nationals and             efficient approach that allows users to
spatial-temporal decision making for                 international SDIs.                     query scattered collections of geospatial


                                                                   27
information through their metadata                      A distributed catalogue service assumes       scientific surveys. It also provides access
descriptions. This geospatial information               some degree of “disseminated” ownership       to physical oceanography parameters.
may take the form of “data” or services                 and     participation  (vs.    centralised
                                                                                                      Furthermore, remote sensing imagery is
described with complementary forms                      approach). Treating metadata and data
                                                                                                      integrated with Meteosat, Modis, AVHRR
of metadata. A distributed catalogue                    as interrelated prevents synchronisation
                                                                                                      medium resolution SST time series. The
environment is more than just a                         problems between data, metadata, and
                                                                                                      GeoNetwork node describes accurately,
catalogue. The distributed catalogue                    externally indexed metadata. Institutions
                                                                                                      availability and accessibility of the relevant
includes references and/or access to data,              managing and editing spatial data are
                                                                                                      datasets with the following capabilities:
ordering mechanisms, map graphics for                   competent to publish and maintain the
data browsing, and other detailed user                  metadata. The metadata catalogue              •	    Local and distributed geospatial
                                                        closely related with data is likely to be           catalogues content-based search.
information that are provided through the
metadata entries. This metadata acts in                 more detailed than external metadata          •	    Records	harvesting,	import/export.	
three roles:                                            (indexed off-site).                           •	    Interactive	 Web	 Map	 Services	
                                                                                                            (intermap).
•	     Describing	 the	 location	 of	 the	              A variety of metadata catalogue tools are
       information.                                                                                   •	    Access	permissions	controls	(groups	
                                                        available for this type of directory search         and user levels).
•	     Describing	the	content	and	structures	           in various national and regional SDIs
       of the information.                                                                            •	    ISO19115	 compliant	 plus	 other	
                                                        worldwide. A recent review of metadata
•	     Providing	the	end-user	with	detailed	                                                                metadata standards.
                                                        editor’s features and capabilities from
       information on copyright and use                                                               •	    Online	 metadata	 edition	 and	
       constraints.                                     the ISO 19115 Metadata Editor Working
                                                                                                            metadata templates.
                                                        Group (FGDC) Federal Geographic
Geospatial information can easily be                                                                  •	    Data	 upload	 and	 download	
                                                        Data Committee is available from www.
identified with a simple search interface                                                                   documents, PDFs and any other
                                                        fgdc.gov/metadata/iso-metadata-editor-              content.
illustrated on Fig. 1 from a GeoNetwork
                                                        review.
node (www.geonetwork.org). Specification                                                              •	    Harvesting	 and	 synchronisation	
of keywords, type of data required,                     Within the framework of the bilateral               between catalogues.
localisation in time and space are                      South African/French project ECO-UP           GeoNetwork is an open source standard-
sufficient for datasets identification. The             (www.eco-up.ird.fr) involving IRD (Institut   based, spatial information management
search request is passed to the catalogue               de Recherche pour le Développement,           platform. It is designed to enable access
gateway which queries one or more                       France) and M&CM (Marine and Coastal          to    geo-referenced     databases    and
registered catalogue servers.                           Management South Africa); a geospatial        cartographic products through descriptive
                                                        node using GeoNetwork was developed.          metadata and is based on international
Each catalogue server manages a
                                                        A fishery geographical information system     and open standards for services and
collection of metadata entries. Within
                                                        (GIS) was implemented.                        protocols     (ISO-TC211     and    Open
the metadata entries are instructions on
how to access the spatial data being                    The main objective of this GIS is the study   Geospatial Consortium specifications).
described. Interoperable search across                  of spatial and temporal relationships         This platform is compliant with the OGC
international catalogues can be achieved                between the different components of the       specifications for querying and retrieving
through use of a common descriptive                     ecosystem, from environmental factors         information from web catalogues (CSW)
vocabulary (thesaurus), a common                        to phytoplankton, zooplankton, pelagic        and supports the ISO19139, FGDC
search and retrieval protocol, and a                    fish (distribution and recruitment), their    and Dublin Core. A GeoNetwork node
registration system for servers of metadata             predators and competitors. This GIS           is WMS, WCS, WFS complaints for
collections.                                            provides access to fisheries statistics and   visualising maps through the internet. Its




Fig. 1: GeoNetwork extended geospatial search interface illustration.



                                                                            28
                                                                                         calculation, model on spatial data,
                                                                                         and any GIS functionality. WPS defines
                                                                                         three operations:
                                                                                         •	    GetCapabilities: returns service-
                                                                                               level metadata.
                                                                                         •	    DescribeProcess:    returns   a
                                                                                               process description (inputs and
                                                                                               outputs).
                                                                                         •	    Execute: returns the outputs.
                                                                                         Such clients can, on line, process simple
                                                                                         topological computations or, as runs,
                                                                                         elaborated climate change models.
                                                                                         The WPS approach goes a step further
                                                                                         in processing spatially referenced data,
                                                                                         by standardisation of processes and
                                                                                         description of their inputs/outputs. The
                                                                                         WPS 1.0.0 was released in December
                                                                                         2007.

                                                                                         SDI is a schema allowing access,
                                                                                         dissemination, processing, of spatial
Fig. 2: Architecture of a GeoNetwork node.
                                                                                         data for decision making, management
                                                                                         and administration. The increase in uses
                                                                                         as well as the improved understanding
characteristics are illustrated in Fig. 2.   Once set-up, such standardised              of marine and coastal environments
In terms of technology, GeoNetwork           distributed    SDI    enables     further   lead to implementation of better
is a web application based on Java           developments and especially web             management        and    administration
servlets that run in servlet-enabled web     processing services (WPS). Data             systems able to deal with greater
server (tomcat, jetty) with XML data         required by WPS can be disseminated         demands. Developing seamless SDIs
representation (JDOM), XSL templates         across a network with both vector and       that can share data from coastal and
for presentation (XALAN), JDBC for           raster data. WPS defines interfaces for     marine environments are needed to
database access (mySQL, Oracle,              publishing geospatial processes. OGC        improve collaborative approaches
PostgresSQL, McKoi), Lucene (1.4.3) to       WPS is designed to standardise the way      between these environments.
search and XML schema for metadata           that GIS processes are made available
editing.                                     on the internet. These processes include    The answer to success in SDI
                                                                                         initiatives is   partnerships     within
                                                                                         and between institutions involved
                                                                                         in marine administration, spatial
                                                                                         information supervision, in situ surveys
                                                                                         management, and Earth observation
                                                                                         data organisation. Research needs to
                                                                                         focus on combining these initiatives
                                                                                         and developing a seamless SDI (Strain,
                                                                                         2005).

                                                                                         Standards, free and open source
                                                                                         software solutions and datasets are
                                                                                         now widely accessible to support
                                                                                         data harmonisation, integration and
                                                                                         interoperability. The main difficulties
                                                                                         are acknowledged to be mainly
                                                                                         organisational.     Partnerships   drive
                                                                                         the implementation of effective SDI,
                                                                                         allowing concerted work to achieve
  “SAEON will contribute to the realisation of a South African                           different goals. Cooperation and a
  Earth Observation System of Systems (SAEOS) and the Global                             spatial data-sharing culture need to be
        Earth Observation System of Systems (GEOSS).”                                    encouraged therefore there is a crucial
            Johan Pauw, Managing Director, SAEON                                         need for an institutional framework that
                                                                                         supports marine SDI development 

                                                               29

				
DOCUMENT INFO