The use and applicability of spatial data in Africa has grown by leaps and bounds during the past few years. Spatial technologies are these days being used for several purposes which include mapping the spread of diseases, discovery of natural resources, monitoring of natural disasters, monitoring of soil and vegetation conditions etc. All this has helped a great deal towards enhancing and accomplishing the Millennium Development Goals in Africa
In the past two or three decades our capacity to survey and map the global environment has seen a “makeover” through the use of Geographic Information Systems (GIS), Remote Sensing (RS) and Global Positioning System (GPS). While GIS application enables the storage, management and analysis of large quantities of spatially distributed data which are associated with their respective geographic features; Remote Sensing is used to gather information about the surface of the earth from a distant platform, usually a satellite or airborne sensor. The two merge when the remotely sensed data used for mapping and spatial analysis is collected as reflected electromagnetic radiation, which is processed into a digital image that can be overlaid with other spatial GIS data of the same geographic site. With their continuous technological development and improvement, Remote Sensing information is increasingly being utilised in undertaking socio-economic developments and technological uplifting of the country, in the federal ministries and provincial departments, public sector organisations, international agencies and private sectors.
GIS and Remote Sensing, either individually or in combination, spans a wide range of applications with degree of complexity. More complex applications take advantage of the analytical capabilities of GIS and RS software. These complex applications might include classification of vegetation for predicting crop yield or environmental impacts and modelling of surface water drainage patterns etc of which some are already being used in Africa. These software are of great use in geological and mineral exploration, hazard assessment, oceanography, agriculture and forestry, land degradation and environmental monitoring around the world. Each sensor in Remote Sensing devices was designed with a specific purpose. The design for optical sensors focuses on the spectral bands to be collected while in Radar imaging, the incidence angle and microwave band used to play an important role in defining which applications the sensor is best suited to.
Example of the areas in which satellite remote sensing technology has been broadly applied in Pakistan, with varying degree of success is as below:
- Disaster monitoring and mitigation
- Survey and urban planning
- Water resource management
- Environmental monitoring
- National spatial data infrastructure
- Infrastructure development planning and monitoring
- Mineral exploration
- Coastal eco-system monitoring
Some of the above projects like Agriculture in Crop Monitoring have been undertaken by Space Upper Atmosphere Research Commission (SUPARCO) in the recent past. It is a good example to African countries to maximise the use of spatial technologies.
During the recent years, more than eight African countries have embraced the idea of spatial technology and even more countries are joining due to its numerous benefits in today’s ever growing population in Africa. Examples of some of the African countries that have already implemented GIS and RS are as below.
Remote Sensing and GIS in Different African Countries
Generally in Africa, GIS and RS have been used in different fields. For weather monitoring, a software package is used to generate daily weather data for Latin America and Africa with the use of Decision Support System for Agrotechnology Transfer DSSAT crop Model. On the health care front, which is an important field today, Africa and other continents like Asia and America monitor vector arthropod surveillance in order to control the anopheles mosquitoes. Communications through television and radio systems also depends mostly on RS and GIS to communicate information from one part of the world to another. RS and GIS also boost communication through mobile devices like telephones. Here are some of the applications of GIS and Remote Sensing in some of the African countries.
The use of the spatial technologies has been maximised in Ethiopia in the following fields:
- Monitoring community forests, land use & soil erosion in Gojan and Shewa, as in the Fig. 1 below
- Natural hazard assessment, specifically in the Wondogenet area in the Eastern margin of the Main Ethiopian Rift, to monitor its logistic regression
- Modelling soil loss rates by integration of the high resolution Modular Optoelectronic Multispectral Stereo Scanner (MOMS-02/D2-Stereo data) in GIS
- Modelling the distribution and abundance of snail intermediate hosts
In Sudan, Remote Sensing and GIS are majorly applied in:
- Integrated study of desertification in the Semi-Arid parts of Sudan
- Soil attributes prediction using terrain analysis and
- Groundwater management and development and Hydrological Modelling in Darfur
Kenya, mostly through the aide of Regional Center for Mapping of Resources for Development (RCMRD), an intergovernmental organisation, which provides sustainable development through generation, application and dissemination of Geo-Information, has aided in retrieving a lot of important data from GIS and Remote Sensing Technology. The data is used for a number of applications, some of which are mentioned below:
- Mangrove Forest management within and adjacent to Kiunga Marine Protected area and Lamu for sustainable management of tropical coastal ecosystem
- Analysis of the distribution of tsetse flies in the Lambwe Valley, using Landsat TM Satellite imagery and GIS to monitor its effects
- Modelling susceptibility of coral reefs to environmental stress
- Monitoring Landscape dominants of anopheles mosquito larval habitats in western Kenya highlands to monitor the spread of Malaria
- Kenya Maize Data Base Project in socio-economic statistics and agro climatic information for the technological needs of farmers
- Analysis of land use/cover changes and urban expansion of Nairobi City
- Assessing fragmentation of western Kenyan rainforests
- Ground water distribution on the crystalline basement, limestone and quaternary volcanic terrain by use of thermal and multispectral imagery for the management of groundwater
- Monitoring of active processes like volcanic activity on Mt. Longonot
South Africa has applied the technology in:
- Fisheries, where continent level assessment of inland fish farming potential was carried out along with an appraisal of aquaculture to contribute to food security in S. Africa as a region
- Monitor degradation patterns in a semi-arid heterogeneous S. African landscape
- Uniquely monitoring community political relations in a digital landscape
In Egypt RS and GIS have been used in:
- Mapping and monitoring land cover and land use changes in the north western coastal zone of Egypt
- Monitoring surface temperature and vegetation indices at a continental scale
- Mapping groundwater potential in watershed mapping at the Sinai Peninsula to obtain an image like in Fig. 2
RS and GIS are used to:
- Monitor semi-arid regions of north-western Nigeria
- Monitor agriculture and land use on the extent of land under crop cultivation, fertiliser usage and the impact of irrigation
In Eritrea RS and GIS are applied in:
- Groundwater study in central highlands of Eritrea
In Zimbabwe, RS and GIS are used to:
- Inventory small water bodies for community fisheries development assessment.
Namibia and Uganda have also applied spatial technologies in fisheries
In accordance to Vorosmarty, et al, 2005, since 1990, there has been a 90 percent reduction in routine reporting of Africa river discharge to relevant international agencies such as the World Meteorological Organization (WMO) Global Runoff Data Center. Africa has a fast growing population, enormous expanses of dry land, extensive poverty, and lack of investment in water, infrastructure and chronic health problems. This has caused most African countries to try and implement spatial technologies like GIS and RS to spurt their growth rate. There are few African countries that are already using these technologies, but many more are now looking to use these technologies. The continuous use of these technologies for various purposes such as monitoring of natural hazards and spread of diseases will surely go a long way in overcoming these challenges.
The application of these technologies should be widely introduced to all African countries, to bring Africa on a global spatial data platform. Consequently, African Geoscientists may be able to work out projects between different countries, thereby enhancing the global correlation of African countries in development issues. Major destructive adverse events like flooding are a common occurrence in Africa. Therefore, the use of RS and GIS can be applied to monitor the affected areas. Applications RS and GIS in the search of valuable natural resources like gold, should also be up-scaled.