The GLOWA Volta Geoportal an interactive geodata repository and information system

TheGLOWA Volta Geoportal

an interactive geodata repository and information system

Dr. Serge Shumilov, Joscha LaubachDepartment of Computer Science III

Antonio Rogmann, Peter WittkötterCenter for Development Research (ZEF)

University of Bonn

2 Antonio Rogmann / Serge Shumilov

What is Geoportal?What is Geoportal?

Easy interactive remote access to the GLOWA Volta data service

Geoportal is a Web-based information system providing:

Data server

Data catalogData catalog

Web Browser

SMB

Internet

Web server

GeoportalGeoportal

Data storage

Data storage

ESRI ArcGIS Client

Intranet

HTTP

WMS Client Web 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


What Services does the GeoPortal provide?What Services does the GeoPortal provide?

Based on internationally approved standards the GeoPortal provides a variety of services:


Main Characteristics of the Geoportal ArchitectureMain Characteristics of the Geoportal Architecture


Component-based Geoportal ArchitectureComponent-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 RuntimeESRI ArcGIS Engine Runtime

JSP/JavaGeoportal

DataManagers

OrganizerOrganizer

Viewers

Data storage

ESRI DBESRI DB

ESRI DBESRI DB

ESRI DBESRI DB

…

File system

Data catalog

Geoportal DB

Downloaders

SearchSearch

MetadataManagerMetadataManager

UserManagerUserManager

ContentManagerContentManager

MapViewerMapViewer

GoogleMapViewerGoogleMapViewer

DataViewerDataViewer

DataManagerDataManager

DataDownloaderDataDownloader

MapDownloaderMapDownloader

Virtual Machine (VMware)

JDBC

SMB / NFS


The GLOWA Volta Geoportal The GLOWA Volta Geoportal

Data search find and assess download

Interactive geodata compose, view and

analyze on map download from map

Publish and share data index and administrate assign use rights upload for distribution


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 GeoportalUser 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



„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


Meta Data in the Catalogue-System 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


Search for Data and DocumentsSearch 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



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



More approaches to find data, documents (and maps)


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 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


Search Data by Relations in Meta Data SetSearch 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


Data Download 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)


Protection against unallowed DownloadProtection 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 email)

Administration tool to generate user accounts and ...

... for user-group management


Visualization of Geo-Scientific Data on Interactive MapsVisualization 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


Volta Basin Water Allocation System (VB-WAS)

Types of Interactive MapsTypes 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 supportSeveral the-matic layers in specific scientific context

Population Density 2000 in theVolta Basin

One thematic layer (popu-lation) and one basic layer (basin border)


Access Interactive Maps with Map BasketAccess 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


WMS link to copy for using the WMS in another WMS client like ArcGIS

Organize the Map with Map ViewerOrganize 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


Gain Information with Map ViewerGain 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


Download Data with Map ViewerDownload 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


Contribution of Meta Information to the GeoportalContribution 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


Edit Meta Data with Meta Data InterfaceEdit 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


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 InterfaceEdit Meta Data with Meta Data Interface


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 GeoportalIntegration 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


Standards in data quality (control), naming conventions and exchange formats improve the use and processing of data

Data Management StandardsData 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_1978-1987_monthly.csv

Project Scientific discipline and topic

Spatial coverage Time frame


GLOWA Volta Data Management Workflow describes steps in data handling and transfer

Data Management StandardsData 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


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 GeoportalIntegration of Data into the Geoportal


ZEF-Data-Server

Intranet

External User

Admin

SharedData

UploadedData

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 InfrastructureIntegration 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