THE IMPACT OF URBANIZATION ON ZARIA FLOODPLAINS, NIGERIA
THE IMPACT OF URBANIZATION ON ZARIA FLOODPLAINS, NIGERIA
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Date
2015-08
Authors
ISHAKU, Absalom Abdul
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Abstract
Floodplains as integral part of riverine systems are strongly threatened by changing land use
patterns undermining the balance they create in an ecosystem. This major threat is the so-called
driving force of modernization, economic growth and development- urbanization, which creates
increasing concern about the effects of expanding cities principally on human health, livelihood
and environment.This study exploits the integrated approach of Remote Sensing and GIS
techniques in urban land use change with the aim of analyzing its impacton floodplain
encroachment in Zaria urban area. Zaria Topographic Map was scanned and digitized to extract
the map of the study area and Landsat TM, ETM and ETM+ imageries of 1990, 1999 and 2014
respectively were processed and classified into land uses and were used to generate built-up
layers which were extracted by digitization and converted to polygon shape files and later used
for overlay (clipping) analysis. A Digital Elevation Model (DEM) of the area was created and
used for delineation of floodplain boundary. ArcGIS software 10.1 operational tool was highly
essential and flexible for mapping and analysis of urban growth and characterization of
floodplain encroachment patterns after which the implications of such encroachments were
examined. From the results, great changes in urban land uses were recorded with increasing trend
in urban built-up and bare surface land use classes as well as decreasing vegetation and scattered
cultivation land use classes. Water body indicated fluctuating values associated with seasonal
variation, although pointing to a decrease. The result showed built-up change from 47.46km2 in
1990 to 111.02 km2 in 2014 increasing annually at the rate of 2.65 km2 between 1990 and 2014.
Built-up was found to have encroached into the floodplains by 3.51 km2 in 1990 which increased
to 13.67 km2 of the total of 78.23km2 floodplains. An annual rate of encroachment of 0.42 km2
was found between 1990 and 2014. The study also identified multiple patterns of encroachment
in different areas of the floodplains ranging from expansion to linear or strip patterns which are
associated with urban sprawl due to uncoordinated urban development especially around river
systems. As a result of this extent and pattern of encroachment, strong institutional framework
and investment with active community participation towards effective floodplain management is
recommended
Description
A DISSERTATION SUBMITTED TO THE SCHOOL OF POSTGRADUATE
STUDIESAHMADU BELLO UNIVERSITY ZARIA, IN PARTIAL FULFILMENT OF
THE REQUIREMENTS FOR THE AWARD OF MASTER OF SCIENCE (M.Sc)
DEGREE IN REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEM.
DEPARTMENT OF GEOGRAPHY
FACULTY OF SCIENCE
AHMADU BELLO UNIVERSITY, ZARIA,
NIGERIA.
Keywords
IMPACT,, URBANIZATION,, ZARIA FLOODPLAINS,, NIGERIA,