By Ibrahim Gumel
Remote sensing is basically the science and art of acquiring information about an object or phenomenon without direct contact with the object or phenomenon using sensors that operate within the electromagnetic spectrum. In other words, it can be defined as the acquisition of information which is usually in image form about the land masses and oceans and also the atmosphere above it by spaceborne sensors. The latter definition is what is sometimes referred to as satellite remote sensing.
Remote Sensing technology has been around for quiet along time. The earliest device for recording images from electromagnetic radiation was the black and white photograph. Not until around 1946, remote sensing data is collected only from aeroplanes and balloons as photographs. Satellite remote sensing kick-started in the 1960s with the launch of a satellite called TIROS 1. But for environmental Remote Sensing, the breakthrough came in 1972 when the first Earth resources satellite (ERTS-1) later called Landsat-1 was launched by NASA.
This was a turning point in history as one author states: “In the entire history of science, there has never been an event equal to the advent of Landsat-1 for the peaceful sharing of scientific data”. This is so because, for the first time, satellite data of any place on earth can be available to anyone that wishes to have it. The advent of Landsat-1 opens the door for effective environmental Remote Sensing. This was aided with fact that for the first time multi-spectral images are a reality.
Later, Landsat thematic mapper (TM) 4 and 5 were launched in 1982 and 1984. This offered a significant improvement in data acquisition capability over Landsat-1(MSS). All these have contributed immensely to the development of remote sensing technology. The advancement in satellite remote sensing technology, especially with the development of more powerful multi-spectral and hyperspectral sensors on satellites has helped in better understanding of urban areas and the intricacies and complexities of cities around the world.
Over the last century, the world has witnessed rapid urbanization. Now, over 50% of the world’s population are said to be living in cities. This rapid growth comes with major problems especially in developing countries like Nigeria. Policy makers and urban planners struggle to manage such growth and its challenges. These challenges made some countries to resolve that the only solution is to undertake the daunting task of constructing new cities which will be planned from scratch. Such cities are expected to be better, efficient and easier to manage.
Abuja is a member of the exclusive club of such planned cities in the world. A club shared by cities like Brasilia, Canberra, Naypyidaw, Islamabad and Dodoma. Abuja city is the first pre-planned city in Nigeria. The city design and development are strictly based on a Master Plan designed by a US-based consortium, International Planning Associates in 1979. The Master Plan produced defined the structure and overview which was supposed to be the basis for the progressive development of the city in four phases. The Master Plan carved out an area of about 8000km2 as an area to be termed as Federal Capital Territory (FCT), and the actual Federal Capital City will cover an area of 250km2. The Master Plan proposed that 49% of the territory development should be residential, 32.5% for recreational areas including green and open space, 16.5% for light industries, commercial activities and other related services and 2% for government usage. The whole four phases were expected to be completely developed with a population of about 3.2 million by the year 2000. Most of these recommendations by the Master Plan are things we can critique and verify using Remote Sensing and Geographic Information System (GIS).
Moreover, using remote sensing to go back in time, we were able see that as at 1976 when Abuja was declared as the new capital of Nigeria, there isn’t much impervious surface (which is an indication of urban area) in and around the area marked for the Federal Capital City (FCC). The total area of impervious surface in the area based on a research we conducted is about 1000 hectares. By 1986 we are able to see that about 3400 hectares of land have been developed, even though this is far short of the 7400 hectares recommended by the master plan.
This is obviously one of the reasons why the capital was only moved in 1992 when about 5000 hectares of construction has been completed. By 2014, a total of about 18,000 hectares of land have been developed. This doesn’t include parks and open space; it is only the area of impervious surface constructed in and around the four development phases of the FCC.
Using remote sensing and GIS we were able to see Abuja slowly coming to life. The neighbourhoods are gradually been built, roads paved and the marvellous arch shape of the city beginning to appear. The planning and the massive investment it took into developing a modern, advanced and contemporary city like Abuja was simply remarkable to observe especially in the first two decades of the city.
The vision to create Abuja and the fantastic people that have worked early on to bring this vision into life is nothing short of exceptional. But recently, the labour of our heroes past and present is slowly being jeopardised as a result of many avoidable reasons, as I observed in some of the studies I conducted on the city. Unplanned settlements are becoming rampant and the policy makers and the city planners are either unaware, or don’t seem to have the necessary technology and skills in place to detect, monitor and manage this major issue that is threatening the soul of the city.
Only remote sensing combined with GIS can give us the ability to time travel back into the past, to see with high level of precision how a city like Abuja started its life, from its most humble of beginnings (having no single paved road) to its current position of strength and prestige, not just in Nigeria but across the world, where, despite current challenges, it is seen as one of the most scenic planned cities in the world.
Follow me in the second part of this piece to see how Abuja is evolving in the recent decades, the various challenges it is facing, and some recommendations on how to tackle them. We will also see how remote sensing and GIS can give us the ability to time travel into the future and model the pattern and direction of how Abuja is expected to grow in 10-20 years from now.
Gumel, an Urban Development Specialist who specialises in Remote Sensing wrote from St. Louis, Missouri, USA mallamgumel@gmail.com
