The GLOWA Volta Geoportal an interactive geodata repository and information system

1. TheGLOWA Volta Geoportalan interactive geodata repository and information system Dr. Serge Shumilov, Joscha Laubach Department of Computer Science III Antonio Rogmann, Peter Wittkötter Center for Development Research (ZEF) University of Bonn

2. WMS Client Web Browser Internet Web server Data server HTTP Data catalog Geoportal JDBC Data storage SMB / NFS HTTP Intranet SMB WMS Client Web Browser ESRI ArcGIS Client What is Geoportal? Geoportal is a Web-based information system providing: • Easy interactive remote access to the GLOWA Volta data service • Cataloguing and management of heterogeneous datasets • Services to publish, access and share data over the internet • Tools for interactive search, visualization and analysis of data

3. What Services does the GeoPortal provide? Based on internationally approved standards the GeoPortal provides a variety of services:

4. Main Characteristics of the Geoportal Architecture

5. Component-based Geoportal Architecture Geoportal architecture consists of several components providing particular portal's functionalities. Data server (Linux) Virtual Machine (VMware) Web server (Windows) Geoportal DB Apache Web server / Tomcat Geoportal JSP/Java JDBC DataManagers Viewers Data catalog MapViewer Search GoogleMapViewer DataManager Data storage DataViewer MetadataManager ESRI DB Downloaders Organizer File system DataDownloader UserManager ESRI DB MapDownloader ContentManager SMB / NFS … ESRI DB ESRI ArcGIS Engine Runtime

6. The GLOWA Volta Geoportal Data search • find and assess • download Publish and share data • index and administrate • assign use rights • upload for distribution Interactive geodata • compose, view and analyze on map • download from map

7. User and Operations in the Geoportal • The range of operations provided by the Geoportal is determined by the assignment of the user to a functional group • The goal is to warrant a coordinated web-based access for indexing, up- and downloading of data and management of the system ... ... with focus on the protection of owner rights of the resources hosted by the Geoportal!!

8. User and Operations in the Geoportal • „Consumer“ – Level • Guest (registered as “all” in the user database) • search in meta data catalog • visualize map based geodata with Map Viewer • download data in public domain • don’t need to be registered personally in the Geoportal • Member of a specified user group (e.g. an institutional group) • same operation as the “guest”-user • download of data with access rights only for his user group • needs to have an user account in the Geoportal

9. User and Operations in the Geoportal • „Contributor“ – Level • Meta Data-Uploader • enter, delete and upgrade of your ownmeta data sets • determine which user groups are allowed to access their data indexed in the catalog • „Administrator“ – Level • Meta Data-Administrator • control, edit, delete and approve of all meta data sets • Geoportal-Administrator • administrate user database and content of Geoportal

10. Meta Data in the Catalogue-System • The GLOWA Volta Geoportal offers several ways to find data and other resources (documents, maps, applications) in the GLOWA Volta datastock by using the catalogue service ... • The data are indexed in a catalogue consisting of a range of meta data elements • This meta data elements provide detailed information, usable to assess if the resources are applicable for the own requirements of data processing and information

11. Search for Data and Documents Approaches to find data and documents by „search in meta data“ Keyword-based search in all catalog elements. Filtering by „AND“ search relation Selection for geodata embedded in Web Map Services only Search in predefined subject / topic list

12. Advanced search to find data by criteria based on selected catalog elements Search for Data and Documents Approaches to find data and documents by „advanced search ...“ Combination of different criteria frequently used

13. Search for Data and Documents More approaches to find data, documents (and maps)

14. Detailed Description Short List Meta data sets which seem to be interesting can be reviewed in a detailed description within the data viewer Scroll through a result shortlist Search Results in Data Viewer Basic information needed to assess the data in relation to its usability is provided in the long version of the meta data set

15. Topical relationships between resources (raw-data  processed data) can be browsed through meta data sets Search Data by Relations in Meta Data Set Uniform Resource Name (identifier) acts as link to related data set Meta data set can be downloaded as text file

16. Data Download By obtaining the proper access rights,data can be downloaded directly from the catalog search result Delivered as compressed file (.zip) Download button Permanent link can be copied and used e.g. in favourite lists

17. Protection against unallowed Download Administration tool to generate user accounts and ... • The major part of data in the GLOWA Volta datastock is protected by owner rights • To access protected data, the user has to have an user account in the Geoportal ... for user-group management • The data of interest needs to be assigned in the meta data setto the user-group of which the user is a member • To get a membership,the Geoportal administrator has to be contacted by the user (by email)

18. Visualization of Geo-Scientific Data on Interactive Maps • Geo-scientific data are stored in different formats with different behavior in the Geoportal • Single raster and vector files • Relational geodatabases • Map Projects (mainly ESRI ArcView and ArcGIS format) • Web Map Services Meta data editor with elements to describe geo-data properties • Web Map Service (WMS) displays spatial data • in its cartographic context • interactively by providing fundamental GIS functionalities • as raster images separated from the (protected) original geo data • using a common internet browser • WMS: specified by the Open Geospatial Consortium (OGC) • supported by a broad range of GIS-clients (ArcGIS, GRASS, Open Jump, ...) • interoperable with other, distributed Open GIS-services: WMS, Web Feature Service (WFS), Web Coverage Service (WCS), ....

19. Population Density 2000 in theVolta Basin Volta Basin Water Allocation System (VB-WAS) Types of Interactive Maps • The Geoportal provides two kinds of interactive maps as Web Map Services One thematic layer (popu-lation) and one basic layer (basin border) • Single WMS layers • searchable in the catalog and to be combined in one map viewer interface by the map basket • mainly used to • assess geodata in order to download and process locally • analyze spatial relationships for decision support Several the-matic layers in specific scientific context • Project maps • composed of several layers with specific symbolization • mainly aimed to inform about GLOWA Volta Project research

20. Direct download is yet possible Access Interactive Maps with Map Basket The Map Basket is a service to combine several WMS in one Map Viewer interface Search only WMS Add WMS of interest to the map basket Result List Selectable layers for download. If required, together with the map project file (.mxd) Content of map basket

21. WMS link to copy for using the WMS in another WMS client like ArcGIS Organize the Map with Map Viewer The map viewer is a cartographic interface in a web-browser Manipulation of layer visibility and display range on map Legend corresponds with visible layers Three WMS

22. Gain Information with Map Viewer Example: NDVI is composed with climate stations (linked with rainfall time series) Info button activation followed by mouse-click on map-object provides object related information Compare 1. WMS: mean annual NDVI with 2. WMS: mean yearly rainfall Additional information: link to meta data set in order to get detailed information about the station Additional information: Further available climate parameters collected by climate station

23. Download Data with Map Viewer WMS only displays interactive images of maps. Usable data are to be downloaded – if allowed for the user Layer of interest can be selected

24. Contribution of Meta Information to the Geoportal • Data about data (meta data set = catalog entry) describes data and resources - independently of the data storage location • Web-Services (e.g. for data download) offered by other institutions can be linked within a meta data set • Lacking web-based facilities for data distribution: “contact” information leads on the way to get data Offline (in the field) created catalog entries can be uploaded Meta data uploader gets the meta data upload tool Delete and edit own catalog entries Add new catalog entry

25. Edit Meta Data with Meta Data Interface • Uniform Resource Name Generator (URN) gives each dataset described in the catalogue an unique identifier URN syntax reflects properties of the described resource Uniform Resource Name is automatically generated • Unique identifiers avoid redundancies and confusion in the datastock

26. Edit Meta Data with Meta Data Interface • The Editor provides an easy to use interface with about 25 element fields Assignement of users or user-groups allowed to gather the dataset. Only needed if dataset is stored in the Geoportal data bases ready for download • Fill in of all elements is not mandatory • Range of elements can be extendedflexibly if needed • Quality of entries controlled by Meta Data Administrator

27. Integration of Data into the Geoportal • Data indexed in the Geoportal Catalog can be located • outside or inside of the central database hosted by GLOWA Volta (or another hosting institution) • Advantage to store distributive data on the central data server: use of Geoportal Services to share data via web • Integration of own datasets into the central database needs … • … a registration to get the necessary meta data upload and administration rights (contact the Geoportal administrator) • … the consideration of certain standards in regard to the preparing of data which is going to be shared

28. Project Scientific discipline and topic Spatial coverage Time frame Data Management Standards • Standards in data quality (control), naming conventions and exchange formats improve the use and processing of data • To inform about the level of data quality just gives the data quality! Meta data element Quality control • Significant file naming simplifies the organization of data files (e.g. after download on the local machine) glowa_hyd_discharge_arli-dou-burkinafaso_1978-1987_monthly.csv

29. Data Management Standards GLOWA Volta Data Management Workflow describes steps in data handling and transfer Step 2: identify the data by assigning an URN and/or name Data management step icons are linked with explaining documents • Workflow will be published as web-page close to the Geoportal!

30. Local Area Server Area Integration of Data into the Geoportal Upload of data sets, documents and other resources to the central database Data upload as next step after meta data upload This was shown before

31. Distribution Integration Local Data Extern ZEF-Inhouse ZEF- Member External User Intranet Geoportal SSH Shared Data Meta DB Central Data base Uploaded Data Transfer Area Open Area Secure Area Admin ZEF-Data-Server Integration of Data into the Geoportal Infrastructure Data transfer at the Center for Development Research (ZEF) • Coordinated data integration and distribution Registration and login- data transmission • Administrator controlls integration • Only quality controlled data meeting the standards is transferred into the central data bases – ready for distribution Administrator restores new uploaded data