UNIVERSITY OF NAIROBI DEPARTMENT OF GEOSPATIAL AND
SPACE TECHNOLOGY.
Supervisors: 1. Dr. F.N. Karanja 2. Mr. S. Nthuni
By: Mbuta K. Shadrack 18.05.2015
MAPPING URBAN SPRAWL AND ITS IMPACTS - A CASE STUDY OF RUIRU
SUB-COUNTY, KIAMBU COUNTY.
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Outline Title
Background Problem Statement
Objectives
Methodology
Results
Analysis
Conclusions
Recommendations
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Background • Population increase and unplanned
urbanization in Kenya-rapid expansion of the urban centers-lack basic amenities
• UNEP and ICLEI-Africa has the fastest rates of urbanization worldwide
• population increase - need for new housing, schools and infrastructure dependency on automobiles-air pollution.
• Loss of precious farmlands, increased runoff/flooding
• In Kenya urbanization- radial or linear. • Identification of sprawl help in effective
infrastructure planning in urban areas.
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• Sprawl-threat to areas around the city.
• the consequences are environmental, socio-economic, emotional and aesthetic.
• Open data source-Kiambu has a population of 1,673,785 and out of this, 1,017,376 are living in urban areas-60% urbanized
• Earlier studies on sprawl have been in developed countries-gap for study in developing countries
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Problem statement
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Objectives Main objective 1. To demonstrate how GIS and remote sensing can be used to effectively study urban sprawl and its effects Specific objectives 1. To determine the spatial extent of urban sprawl in Ruiru between 2003 - 2013. 2. To examine the causes and impacts/effects of urban sprawl in Ruiru Sub County 3. Predict the patterns of future extent of urban sprawl in Ruiru Sub County.
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• County: Kiambu • Population: 238,855 (KNBS 2009) • Area: 179.90 Sq. Km • No. of County Assembly Wards-8 Land Tenure in Ruiru
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-Biashara -Gitothua -Gatongora -Kahawa Wendani -Kahawa Sukari -Mwihoko -Kiuu -Mwiki
Methodology
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Research Design • 2 basic research methods used: • quantitative
• qualitative.
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• Quantitative- involve use of GIS produce maps of urbanization
• GIS easily allowed reclassification of land cover data into categories & usage of different types of data
• The qualitative- interviews with local land developers, planners, and analysis of jurisdictional comprehensive plans
• understanding of multivariate phenomenon
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Data sources & Tools • National and Regional administrative boundaries • Land use data, • satellite imagery, • infrastructural data • Data on the economic activities in the study area • Data on urban development activities
• Scheduled interviews • Observation Guides • Photography • Maps and Satellite Imagery
• Statistical Softwares e.g. Microsoft Excel, • ArcGIS software was used to generate maps
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Data Collection
Data pre-processing
Mapping urban sprawl • Visual & supervised classification
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Signature collection on an image
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Supervised Classification on a Satellite Image
15 The results obtained were improved by some steps of post-processing, for accuracy
Results
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Year Of Study
Area
2003(Ar
ea In
Km2)
% of
Total
2009(Ar
ea In
Km2)
% of
Total
2013(Area
In Km2)
% of
Total
Built up area 7.10 8.5 12.39 14.9 21.20 25.5
Water bodies 1.44 1.7 2.18 2.6 2.89 3.8
Agricultural
land
18.40 22.1 15.59 18.7 16.41 19.7
Vacant/other
lands
56.31 67.7 53.09 63.8 42.75 51.0
Total Area 83.25 100 83.25 100 83.25 100
Trend changes Year Of Study
Area
Change Between
2003 And 2009
Change Between
2009 And 2013
Change Between
2003 and 2013
Built up area 7.8 8.81 16.61
Water bodies 0.74 0.71 1.45
Agricultural land -2.81 0.82 -1.99
Vacant -3.22 -10.34 -13.57
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Year Of Study
Area
Built Up
Change -2003 & 2009 7.8
Observed change/ Sum of
change × 100
7.8/33.22 * 100 = 23.48%
Change -2009 & 2013 8.81
Observed change/ Sum of
change × 100
8.81/33.22 * 100 = 26.52%
Change -2003 & 2013 16.61
Observed change/ Sum of
change × 100
16.61/33.22 * 100 = 50%
Trend Percentage Change
Area Covered by Each Land Use/Land Cover
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22
0
20
40
60
80
2003(area in km2) % 2009(area in km2) % 2013(area in km2) %
CHART SHOWING AREA AND % COVERED BY EACH LAND USE /LAND COVER
Built up area Water bodies Agricultural land Vacant/other lands
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Combined Built- Up Area Map (2003-2013)
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(2003-2013) types of sprawl-leap frog
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(2003-2013) types of sprawl-linear
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(2003-2013) potential future sprawl
Impacts of sprawl in Ruiru sub-county Demography • As per the 2009 census, Ruiru sub-county population-
238,858, • Projected to reach 299,067 by the year 2017
Economic • The sub-county has grown economically – with close to
100 million shillings collected from development applications/plans annually
Environmental • Poor Solid waste management-one dumpsite in Thika • Lack of conventional sewer line (one under construction) Poor Roads/infrastructure Land fragmentation Loss of agricultural land/habitat Strain on infrastructure
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Section of the Ruiru Sewerage Works under Construction
Conclusions and recommendations • Urban sprawl is the uncontrolled and unplanned
outgrowth of towns and cities • urban sprawl is a threat for achieving sustainable
urbanization • Ruiru town, faces real challenges - basic
infrastructure and services. • The entire sub county is one of the expensive places
in Kenya to own a land with an acre of land going up to KES 40M.
• A lot of growth especially in Gitothua (Tatu city) and Gatongora wards
• Urban sprawl in Ruiru is in two patterns-Linear (along major roads/by-passes) & Leap frog in Gatongora ward
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Recommendations
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OBJECTIVE ISSUES RECOMMENDATION Mapping Urban Sprawl
No Database Dev't
Mapping of Resources Land uses/Land cover Maps Investment in basic GIS resources Invest on IT
Poor resource management
Put in place resource management mechanisms
Spatial Extend of Urban Sprawl
Uncontrolled Growth
Initiate Dev’t control
Linear sprawl along major transport lines
provide guideline on development Encourage public participation Control development Causes &
Impacts Of Urban Sprawl
Increased pop’n in Ruiru Sub County
Economic growth and Service Delivery
Categorize revenue sources Monitor Financial channels Public involvement in Budgeting & Decision making
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Infrastructural issues
Improve roads Develop sewerage & drainage system Parking footpaths and cycling lanes
Loss of Water bodies and wetlands
Protection of riparian reserves
Loss of agricultural
To enhance urban agriculture To control development
Waste management problems
Develop management systems Privatize the solid waste collection sector
Policy Framework
Poor planning regulation
develop & implement zoning plan
Enforcement of laws and policies
Strengthen institutions through capacity building and implementing laws
Thank you!
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