Bathymetry

Approach

The EMODnet Bathymetry portal is operated and further developed by a European partnership. This comprises members of the SeaDataNet consortium together with organisations from marine science, the hydrographic survey community, and industry. The partners combine expertises and experiences of collecting, processing, and managing of bathymetric data together with expertises in distributed data infrastructure development and operation and providing OGC services (WMS, WFS, and WCS) for viewing and distribution.

SeaDataNet is a leading infrastructure in Europe for marine & ocean data management, initiated and managed by the National Oceanographic Data Centres (NODC's). It is actively operating and further developing a Pan-European infrastructure for managing, indexing and providing access to ocean and marine data sets and data products, acquired via research cruises and other in-situ observational activities. The basis of SeaDataNet is interconnecting Data Centres into a distributed network of data resources with common standards for metadata, vocabularies, data transport formats, quality control methods and flags, and access.

SeaDataNet is aiming for an extensive coverage of available data sets for the various marine environmental disciplines, such as physical oceanography, marine chemistry, biology, biodiversity, geology, geophysics and bathymetry. This is implemented by seeking active cooperation at a national scale with institutes and at a European scale with communities, that are engaged in data management for these disciplines, and by seeking opportunities for including their data centres and data collections in the SeaDataNet metadata and data provision.

In the field of bathymetry, a number of Data Centres in SeaDataNet manage bathymetric data sets, such as multibeam surveys from scientific cruises. However there are several other parties engaged in the provision of bathymetric data. These comprise:

  • Hydrographic Offices, that are responsible for surveying the navigation routes, fairways and harbour approach channels and producing from these the nautical charts on paper and as Electronic Nautical Charts (ENC), that are used for navigation. The HO's are members of the International Hydrographic Organisation (IHO), that has its data policy, which supports restrictions in the delivery of high resolution data sets, mostly for safety and security reasons. Moreover, nautical charts have a legal status. Every ship captain must use certified nautical charts and the production and publication of these is an activity which must follow stringent international procedures. The latter results in a condition that HO's are careful in delivering and distributing bathymetric survey data sets.
  • Authorities, responsible for management and maintenance of harbours, coastal defences, shipping channels and waterways. These authorities operate or contract regular bathymetric monitoring surveys to assure that an agreed nautical depth is maintained or to secure the state of the coastal defences.
  • Research institutes, that collect multibeam surveys as part of their scientific cruises.
  • Industry, especially the energy industry, that contracts multibeam surveys for pipeline and cable routes (in case of windfarms) and the telecommunication industry for phone and internet cable routes.

Concluding, there are 4 types of organisations, that perform bathymetric surveys, thereby partly overlapping and mostly complementing their geographical coverages. Data are collected at different frequencies and even date back to previous centuries.

The EMODnet Hydrography, Seabed mapping. Bathymetry and now ongoing High Resolution Seabed Mapping projects provide an excellent opportunity for cooperation and engagement with parties in the field of bathymetric data sets. The following approach has been adopted for the implementation of the EMODnet Bathymetry portal:

  • Develop a Bathymetry Viewing and Download service on top of a powerful spatial database including various ways for browsing and interacting with the EMODnet Bathymetry digital terrain model and associated metadata by means of information layers and specific functions. It includes WMS, WCS and WFS services (OGC) to share layers also with other portals such as other EMODnet portals, the European Atlas of the Seas, and external portals;
  • Involve research institutes, monitoring authorities, and HO's, in providing bathymetric data sets, only for internal use by project partners for producing Digital Terrain Models (DTM) with specific resolution for each geographical region. The DTM's are loaded and integrated into the portals' spatial database, and made available lfor free downloading as tiles;
  • Include in the portal a metadata data discovery and access service, by adopting the SeaDataNet CDI metadata standard, for providing clear information about the survey data used for the DTM, their access restrictions and distributors, and featuring online shopping request and delivery; this ensures that the bathymetry data sets can also be queried at the SeaDataNet portal.
  • Include in the portal an additional catalogue service, by adopting the SeaDataNet Sextant Catalogue service, for providing metadata on composite DTMs that are contributed by a number of data providers next to or instead of bathymetric survey data.

This system and organizational approach has the following benefits:

  • It facilitates an expansion of the geographical coverage of the EMODnet Bathymetry portal to other seas, because this involves convincing data holders in other sea areas demonstrating a continuation of accepted principles and product services;
  • It facilitates an expansion of the base of background data sets used for the DTM productions with data sets from other data holders, such as more HO's, research institutes, and port & coastal authorities, and industry (energy and telecommunication industries), because the EMODnet model respects possible data access restrictions and distribution conditions as set by data providers to end-users, while the data sets are used internally by a select group of experts for producing and finetuning the DTMs for the regions;
  • The one-stop-shop of SeaDataNet is expanded with metadata references to bathymetric data sets, of which part can be downloaded directly from interconnected Data Centres via the SeaDataNet shopping mechanism and of which another part can be requested from their owners, whereby the SeaDataNet shopping mechanism is of service for routing the requests.
  • The DTMs for the sea regions are made publicly available for browsing and downloading and each gridcell has a reference to the source data (bathymetric survey via CDI, composite DTM via Sextant, and GEBCO in case of gaps) used for determining the water depth in the DTM grid cell.