- Data limitations
This is a problem that has faced GIS users for decades in both developed and developing nations. Finding the money to collect new data and to convert paper maps and data into digital format continues to be a problem. In many cases digital data do exist, but there are issues of confidentiality, national security, etc.
A near national coverage only exists at the scale range of 1:200000 or 1:250000. At 1:50 000, about two-thirds of the land area is covered and at 1:25 000 less than one-third. The coverage at these scales is in analogue form, but is subject to progress in vectorization or at least in raster scanning. No data surveys exist at large scales especially Kenya’s rural areas.
Based on data requirements, general and specialized GIS systems have to be designed for a variety of purposes including:
• for environmental management and conservation.
• for defence and intelligence purposes.
• for governmental administration.
• for resource management in agriculture and forestry.
• for geophysical exploration.
• for cadastral management.
• for telecommunications.
• for utility management.
• for business applications.
• for construction projects.
Many of these applications require common base data. It will be the purpose of an administrative authority to create a spatial data infrastructure by which the base data may easily be exchanged.
of specific interest may be added
3D-vector data for instance can be obtained directly by terrestrial survey equipment such as:
• electronic tacheometers.
• levelling instruments.
• GPS receivers.
• mobile mapping systems.
3D information from aerial photographs may be compiled by analogue or analytical plotters or by digital photogrammetric workstations which are very few and very costly for an effective digital database creation for the public at least.
2. Availability of Geoportals
The need to have organized Geoportals is an essential requirement for an effective web based mapping and GIS as a whole. A number of companies like Ramani communications now act as data warehouses providing limited spatial data to potential customers. In some cases the companies do not actually produce the data themselves, but provide easy access to a catalogue of spatial data products produced by others. Some Geoportals provide attribute and spatial data free, and make their money by selling advertising. For collaborative usage of data for instance in the areas shown below will require documented Geoportals for web usage of the same in other departments.
3. Networking Issues
Network and communication issues involving spatial data is a major overhead in developing countries trying to implement web based GIS. GIS applications require a significant amount of resources on the desktop and with respect to network performance. By its nature a GIS allows a user to have access to and analyze large amounts of data and present the results in a graphical format. Access to these data for real-time display and analysis puts large demands on network communications in terms of costs. Data must be transported across the network to where the desktop application is executed to display the information in an efficient manner. The concept behind networking and the issues that must be considered when planning a network can be summarized into the following categories:
◆ The type of communication that will be used
◆ Local area network (LAN) versus wide area network (WAN) considerations
◆ The speed of the component hubs, switches, routers and network interface cards (NICs)
◆ The operating system and software that are running on the servers
◆ Whether or not a file server- or client server-based architecture will be used
◆ Whether a centralized or decentralized servers will be adopted
◆ Whether or not to use replication when there are multiple servers
All these issues necessitate a huge financial input which many African countries lack. Network GIS can use the cross-platform Web browser to host the viewer user interface. Currently, clients are typically very thin, often with simple display and query capabilities, although there is an increasing trend for them to become more functionally rich.
4. Ownership of Geographic Information system
There are two ways to look at ownership: within and outside the organization. Ownership of the data inside the organization is something the organization like Ramani can control; ownership when viewed from the outside the organization can be more complex. For example, is the Survey of Kenya to own the web based GIS or who should bear the greatest responsibility in terms of control. If the GIS was to be liberalized then various organizations can design the process, make decisions about control and accountability for each layer, set of features in their databases, and tables in the databases. These issues arise as it becomes clear to different units of the organization and country that data they previously regarded as their domain are going to be more easily shared and seen by other users. It is no secret that control of information is about power within the set-up, so the introduction of a new way or organizing and sharing that information—the new GIS—will disrupt the existing lines of power within the organizations and government. A thorny issue comes when the questions about whose budget will be supporting the GIS arise.
5. User Roles
If the GIS is going to support the activities of multiple units within a ministry, department or any other, a basic assumption is that these units/ departments all have a stake in how the ownership is arranged. Sometimes, in state and local government, there are legal restrictions on who may or may not make certain modifications to the data, and
these certainly must be considered. People interact with relational databases through sets of defined roles and privileges. Roles and people are not the same type of thing because one person may, at different times, have several roles.
6. GIS Software
GIS software is the processing engine and a vital component of an operational GIS. It is made up of integrated collections of computer programs that implement geographic processing functions. The three key parts of any GIS software system are the user interface, the tools (functions), and the data manager. All three parts may be located on a single computer or they may be spread over multiple machines in a departmental or enterprise configuration.Four main types of computer system architecture configurations are used to build operational GIS implementations: desktop, client-server, centralized desktop, and centralized server. There are many different types of GIS software categorized into desktop, server (including Internet), developer, hand-held, and others. The most used GIS software typically originates from the United States or Europe. In some cases this results in problems getting copies of the software as well as getting support for the software, particularly if the problem cannot be solved via telephone or email. The market leading commercial GIS software vendors are ESRI, Intergraph, Autodesk, and GE Energy.
Alternative distribution models that are becoming increasingly prevalent include shareware (usually intended for sale after a trial period), liteware (shareware with some capabilities disabled), freeware (free software but with copyright restrictions), public domain software (free with no restrictions), and open source software (where the source code is provided and users agree not to limit the distribution of improvements).
Professional softwares are very expensive to buy and maintain. The term ‘professional’ relates to the full-featured nature of this subcategory of software. The distinctive features of professional GIS include data collection and editing, database administration, advanced geoprocessing and analysis, and other specialist tools. Professional GIS offer a superset of the capabilities of the systems .
7. Lack of adequate Hardware components
The hardware of a GIS is composed of:
• input devices.
• processing and storage devices.
• output devices
Digital data input depends on the type of data to be utilized. Imagery input is possible from analogue images through the use of image scanners. Digital airborne and space-borne systems already use charge-coupled device CCD-sensors to supply the data in digital form.
8. Graphic standards
The purpose of any GIS application is to provide information to support planning and management. As this information is intended to reduce uncertainty in decision-making, any errors and uncertainties in spatial databases and GIS output products may have practical, financial and even legal implications for the user. For these reasons, those involved in the acquisition and processing of spatial data should be able to assess the quality of the base data and the derived information products.
Most spatial data are collected and held by individual, specialized organizations. Some ‘base’ data are generally the responsibility of the various governmental agencies, such as the National Mapping Agency, which has the mandate to collect topographic data for the entire country following pre-set standards. These organizations are, however, not the only sources of spatial data. Agencies such as geological surveys, energy supply companies, local government departments, and many others, all maintain spatial data for their own particular purposes. If this data is to be shared among different users, these users need to know not only what data exists, where and in what format it is held, but also whether the data meets their particular quality requirements. This ‘data about data’ is known as metadata.
The International Standards Organization (ISO) considers quality to be “the totality of characteristics of a product that bear on its ability to satisfy a stated and implied need” (Godwin, 1999). The extent to which errors and other shortcomings of a data set affect decision making depends on the purpose for which the data is to be used. For this reason, quality is often define as ‘fitness for use’.
Traditionally, errors and accuracy in paper maps are considered in terms of
1. attribute errors in the classification or labelling of features, and
2. errors in the location, or height of features, known as the positional error.
There is therefore need to define the following concerning geo data for usage on the internet and the body to define them is not yet defined.
Managing access to geodata may present a considerably more difficult challenge for Kenya in trying to implement web based GIS. There is a long history of disagreement on the issue of geodata sharing both within the country and in the rest of east Africa. No two countries have quite the same policies and procedures for the use of geodata, and there is no settled and accepted law or custom on this matter. Intellectual property rights, ownership, the right to change or modify the geodata, the means of paying for use, the appropriate charges, the control of who can access the data and for what purpose, permission for a user to modify the geodata, permission to resell the geodata, the means of access, the extent of the user community, and many other concerns are resolved in different ways by different organizations that own or maintain digital geodata.
9. Lack of qualified staff
This is the issue that most frequently mentioned in the field of GIS. The fact that GIS is a relatively new technology means that staff with GIS training and skills are in high demand and beyond the reach of most existing departmental budgets in retraining.
The people to use these systems are typically technically literate and think of themselves as GIS professionals (career GIS staff) with degrees and, in many cases, advanced degrees in GIS or related disciplines.
This is the main hindrance and the effects are well manifested in all sectors of the economies of the developing world.