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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