GIS Viewer - National Oceanographic Data Committee
Original (non-English) name
Acronym
GIS Viewer - NODC
Citation
Abstract
An NODC GIS Viewer application has been set up, that combines topographic and bathymetric charts from Rijkswaterstaat and TNO by means of WMS services. The NODC GIS viewer is based upon the Minnesota Map Server (MMS). The viewer also includes a WMS layer for oil & gas licences and infrastructure (pipelines, platforms) at the Netherlands part of the Continental Shelf.
The NODC GIS viewer has been extended with a demonstrator for an ‘oilspill’ simulation-application based upon the Deltares kernel ‘Delft3D-Part’ with the so-called ZuNo grid (Southern Northsea) as area. The model requires input for discharge (time, quantity, location), windconditions (speed, direction) and water movement (tides). A discharge situation is computed for 5 days from the moment of spill in steps of 1 hour. The characteristics of different types of oil have an influence on the movement and behaviour of the oil spill. Users can define their input for the simulation on the Netherlands part of the North Sea via a separate webpage.
A user can defne e.g. the winddata. For the water movement an astronomical tidal cyclus has been composed which is predefined and fixed. The results of the simulations can be viewed dynamically via the NODC GIS viewer. Therefore the simulation results are written in NetCDF (CF) format. NetCDF is a binary format, which is nowadays very popular in the operational oceanography for the output of forecastingmodels. It provides in combination with OpenDAP an efficient mode for delivering modelresults, also supporting subsetting. For the NODC demonstrator, Deltares has set-up a Web Map Server (ncWMS, developed by the University of Reading), that can serve the simulation results (in NetCDF) as a WMS chartlayer. So the NODC GIS viewer can integrate this WMS layer with the other layers and also offer the possibility to prepare and present an animation of the oilspill.
Deltares has written a Java application shell, the OilSpillManager (OSM), around the simulation model. The OSM receives the user input and converts it into model input. Requests for simulations are placed in a row and sequentially processed. As final step, an e-mail is sent by the OSM to inform the user, that the results are ready for viewing. Each cycle takes about 15 minutes due to the intensive model computations.