The GLOWA Volta Geoportal an 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 Antonio Rogmann / Serge Shumilov What is Geoportal? Easy interactive remote access to the GLOWA Volta data service Geoportal is a Web-based information system providing: Data server Data catalog Web Browser SMB Internet Web server Geoportal Data storage ESRI ArcGIS Client Intranet HTTP WMS ClientWeb Browser HTTP SMB / NFS JDBC WMS Client 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 Antonio Rogmann / Serge Shumilov What Services does the GeoPortal provide? Based on internationally approved standards the GeoPortal provides a variety of services: Searching and filtering of available datasets on the attribute level Browsing through a comprehensive data catalog and thematic maps Catalogue Services Interactive mapping services for cartographic representation of spatially referenced data Tools for visual exploration and analysis of data Portrayal Services Download of selected data (metadata) Interactive means for creating, upload and managing of data (metadata) resources Portal Services Users administration and security facilities Meetings planer and notifications to enable communication and exchange of geoscientific information within defined groups Administrative Services

4 Antonio Rogmann / Serge Shumilov Main Characteristics of the Geoportal Architecture Expandable set of exchangeable active components (Java/JSP) for visualization, downloading and management of data ISO-compatible data catalog based on the Dublin Core metadata standard ensures compatibility with other catalogs Portal interfaces based on the specifications issued by the Open Geospatial Consortium (OGC) ensure that the portal and the data catalog can communicate with other catalogs and clients Virtualization of the web server improves portability of the Geoportal and significantly simplifies its installation The use of open source software based ensures cost-efficiency ESRI Arc Engine is a sole commercial software needed to access ESRI databases

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

6 Antonio Rogmann / Serge Shumilov The GLOWA Volta Geoportal Data search  find and assess  download Interactive geodata  compose, view and analyze on map compose, view and analyze on map  download from map download from map Publish and share data  index and administrate  assign use rights  upload for distribution

7 Antonio Rogmann / Serge Shumilov 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!! User and Operations in the Geoportal

8 Antonio Rogmann / Serge Shumilov 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 Antonio Rogmann / Serge Shumilov User and Operations in the Geoportal „Contributor“ – Level  Meta Data-Uploader ► enter, delete and upgrade of your own meta 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 Antonio Rogmann / Serge Shumilov 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 Antonio Rogmann / Serge Shumilov Search for Data and Documents Keyword-based search in all catalog elements. Filtering by „AND“ search relation Search in predefined subject / topic list Approaches to find data and documents by „search in meta data“ Selection for geodata embedded in Web Map Services only

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

13 Antonio Rogmann / Serge Shumilov Search for Data and Documents More approaches to find data, documents (and maps)

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

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

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

17 Antonio Rogmann / Serge Shumilov Protection against unallowed Download 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 The data of interest needs to be assigned in the meta data set to 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 ) Administration tool to generate user accounts and for user- group management

18 Antonio Rogmann / Serge Shumilov 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 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),.... Meta data editor with elements to describe geo-data properties

19 Antonio Rogmann / Serge Shumilov Volta Basin Water Allocation System (VB-WAS) Types of Interactive Maps The Geoportal provides two kinds of interactive maps as Web Map Services Project maps  composed of several layers with specific symbolization  mainly aimed to inform about GLOWA Volta Project research 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 Population Density 2000 in theVolta Basin One thematic layer (popu- lation) and one basic layer (basin border)

20 Antonio Rogmann / Serge Shumilov 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 Content of map basket Direct download is yet possible Selectable layers for download. If required, together with the map project file (.mxd) Result List

21 Antonio Rogmann / Serge Shumilov 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 Antonio Rogmann / Serge Shumilov 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: Further available climate parameters collected by climate station Additional information: link to meta data set in order to get detailed information about the station

23 Antonio Rogmann / Serge Shumilov 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 Antonio Rogmann / Serge Shumilov 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 Meta data uploader gets the meta data upload tool Offline (in the field) created catalog entries can be uploaded Delete and edit own catalog entries Add new catalog entry

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

26 Antonio Rogmann / Serge Shumilov The Editor provides an easy to use interface with about 25 element fields Fill in of all elements is not mandatory 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 Range of elements can be extended flexibly if needed Quality of entries controlled by Meta Data Administrator Edit Meta Data with Meta Data Interface

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

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

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

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