Time
travel is normally heard or seen in science fiction movies. Some of the first
thoughts that come into a person’s mind will be, Star Trek, worm hole or Dr Who
travelling through time inside his sophisticated time machine. In its most
literal meaning time travel is a concept that involves one moving through time
as he/she wishes without any regard to the laws of physics, which states that
time always move forward. As fictional as it sounds, physicists are to be
unable to dis-prove that someday humans may have the ability to manipulate the
fourth dimension which will make time travel a reality.
While
humans are still struggling to figure out how to make a time machine that will
allow them to travel years or even decades back to the past and also have a
peep into the future, remote sensing has achieved that a long time ago. With
remote sensing it is now possible to look back decades into how cities develop
and how land cover and land use has transformed over the years. Looking back at
how a city develops, seeing when new neighborhoods are constructed or how new
roads are built and seeing when a famous train station comes to existence is
no doubt an interesting prospect. But what is even more interesting is to see a
whole city unravel in your eyes and as you watch it grows from scratch! This is
exactly the promise held by a planned city like Abuja through the worm hole of
remote sensing.
A
Brief History of Remote Sensing
So what is remote sensing that gives us such power to manipulate time and space? Re-mote sensing is basically the science and art of acquiring information about an object or phenomena without direct contact with the object or phenomena 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 the atmosphere above it, by space borne sensors. The latter definition is what is sometimes referred to as satellite remote sensing.
It is
important for one to understand how remote sensing technology comes into existence
and how it works, because only then will one be able to appreciate what it does
and how it changes our lives in ways that we are not even aware of.
Remote
Sensing technology has been around for quite a long 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 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). The Landsat TM has seven spectral bands, six in the visible and
infrared region and one in the thermal (for measuring temperature data) region
of the electromagnetic spectrum. Over the years, a number of other satellites
have been launched which includes hyperspectral and high spatial resolution
satellites e.g. Ikonos, Spot, Quickbird, GeoEye and Worldview. 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 power-ful multi spectral and hyperspectral sensors on
satellites has helped in better under-standing of urban areas and the
intricacies and complexities of cities around the world.
A Satellite in Space
The
Birth of a City
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 was established in 1976 by the Nigerian government with the intention of
moving the federal capital from Lagos to a more central location in the
country.
Abuja
city is the first pre-planned city in Nigeria. The city design and development
was 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 8000 km2 as an area to be termed as Federal Capital Territory
(FCT), and the actual Federal Capital City will cover an area of 250 km2. 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 us-age.
Actual
construction of the city started in 1981 with the intention of finishing the
development of phase one area of the city (about 7000 hectares) and moving in
by 1986. The whole four phases were expected to be completely developed with a
population of about 3.2 million by the year 2000. All these recommendations by
the master plan are things we can critique and verify using remote sensing
Abuja photograph, 1976
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 is little evidence of
impervious surface (which is an indication of urban area) in and
around the area marked for the Federal Capital City (FCC). By 1986, we are able
to see that about 3400 hectares of land has 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. Using remote sensing we are also
able to model the pattern of how the city will grow 10-15 years into the
future.
Only
remote sensing 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, form its
most humble of beginnings (having no single paved road), to its position of
strength and prestige not just in Nigeria but also across the world, as it is
seen as one of the most beautiful planned and organized city in the world.
Abuja, 2014
