BGS EarthServer - xWCPS Queries
This client shows the ability to combine queries on coverage data with geological properties held in GeoSciML
GeoSciML is based on GML and was designed primarily to describe those geological features shown on geological maps, which have 2D vector based geometry. In terms of web services they have therefore been delivered using WMS and WFS. Geological maps are increasingly being replaced by 3D geological models. Typically spatial models comprise a series of surfaces which are the contacts between rock bodies implied to lie between the surfaces. In EarthServer we have implemented these surfaces as coverages, but it is the rock bodies which carry most of the properties, such as age and lithology, which are of interest to geologists so GeoSciML has been written to describe the rock bodies in relation to their bounding surfaces. This GeoSciML has been added to the extension metadata of the surface coverages.
The purpose of describing 3D models using GeoSciML is to enable the models to be queried against both GeoSciML and coverage properties, for example in order to identify those geological units comprising a particular lithology such as ‘sand’ within a specified depth of the surface. Queries of this type enable spatial models to become vehicles for delivering information to the user community, rather than simply visualisations.
xWCPS queries have been developed that utilise both the coverage values and the GeoSciML description, and an xWCPS query builder has been developed to act as a user friendly interface to these queries. This tutorial application is written as a standalone application that could be deployed and adapted to other services with GeoSciML metadata. The tool allows the user to pick a lithology, the proportion of that lithology as part of the overall composition of the rock, and a depth for the geological surface based on a specified DTM.