CLOUD-ENABLED WEB APPLICATIONS FOR ENVIRONMENTAL MODELLING 1
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Claudia Vitolo , Wouter Buytaert , Yehia El-Khatib , Alastair Gemmell , Sim Reaney , Keith Beven and the EVOp full project team (see bottom of the poster) 1
Imperial College London - 2Lancaster University - 3University of Reading (Now at MetOffice) - 4Durham University
INTRODUCTION Efficient management and decision making requires environmental modelling to be easily accessible, portable and flexible. Deploying models as Web Service is currently the best suitable solution. WS are accessed using standard web protocols, they are platform independent and easily integrated in workflows for easy data retrieval, manipulation, visualisation, and communication. In this study we propose an innovative approach to web-modelling, developed as part of the NERC’s Environmental Virtual Observatory pilot project. WEB STANDARDS
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IMPLEMENTATION I The OGC-WPS standards allow interoperability and ease exchange of information with external sources. I The communication between client and server becomes straightforward. I The web client sends the server a HTTP GET request to execute the process. I Once the execution terminates, the server sends back an XML response which is parsed at the client side extracting the simulated results. I As application state is not maintained by the server, there is much less load on it. This greatly simplifies complicated infrastructure management tasks such as load balancing and failure recovery.
MODELS IN THE CLOUD Models implemented as web services: I TOPMODEL (Beven and Kirkby, 1979), a the semi distributed conceptual hydrological model. I FUSE (Clark et al., 2008), a hydrological model ensemble. Models are deployed into a common infrastructure based on the R data analysis platform. The communication between Python and R is facilitated by the RPy2 connector.
The proposed approach combines the use of Google Maps APIs to explore available data and the Open Geospatial Consortium Web Processing Service standard to deploy models. There are several stable software implementations of the OGC standards, in this project we adopted the Python based PyWPS which allows to communicate with: I R programming languages, for model deployment I GRASS-GIS, for geo-processing EXEMPLAR Data was collected at the following four locations in the United Kingdom: I River Eden catchment (Cumbria, England): . Dacre Beck at Dacre Bridge . Blind Beck I Dyfi catchment: Dyfi Bridge (Machynlleth, Wales)
CONCLUSION I Web Services are excellent tools to deploy environmental models using worldwide accepted standards to ease interoperability and communication between devices. I Web applications for data storage and manipulation are seamlessly link with visualisation tools to provide a collaborative shared research environment. I Example applications are accessible via the main EVOp portal and focus on simulating the impact of land-use changes on flood risk and diffuse pollution.
I Tarland catchment: Coull Bridge (Aberdeenshire, Scotland) Data are retrieved by querying a local PostgreSQL database in real time.
THE FULL EVOp TEAM Lucy Ball (CEH), Gordon Blair (Lancaster University), John Bloomfield (BGS), P. Brewer (Aberystwyth University), Lucy Cullen (CEH), Julie Delve (CEH), Bridget Emmett (CEH), Jim Freer (Bristol University), Sheila Greene (Reading University), Robert Gurney (Reading University), P.M. Haygarth (Lancaster University), Penny Johnes (Reading University), Jane Lewis (Reading), E. Mackay (Lancaster University), M. Macklin (Aberystwyth University), Kit Macleod (James Hutton), K. Marshall (The James Hutton Institute, Aberdeen), Adrian McDonald (Leeds University), Nick Odoni (Bristol University), Barbara Percy (Reading University), P.F. Quinn (Newcastle University), Gwyn Rees (CEH), M. Stutter (The James Hutton Institute, Aberdeen), Bholanath Surajbali (Lancaster University), Doerthe Tetzlaff (Aberdeen University), N. Thomas (Aberystwyth University), John Watkins (CEH), M.E. Wilkinson (Newcastle University, now at The James Hutton Institute, Aberdeen), Bronwen Williams (CEH).
For more information visit http://www.evo-uk.org
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