INSTITUTEUrbanization and Spatial Connectivity in Ethiopia: Urban Growth Analysis Using GIS

INTERNATIONAL FOOD POLICY RESEARCH INSTITUTE • ETHIOPIAN DEVELOPMENT RESEARCH INSTITUTEINTERNATIONAL FOOD POLICY RESEARCH INSTITUTE • ETHIOPIAN DEVELOPMENT RESEARCH INSTITUTE

Urbanization and Spatial

Connectivity in Ethiopia:

Urban Growth Analysis Using GIS

Mekamu Kedir and Emily Schmidt

INTERNATIONAL FOOD POLICY RESEARCH INSTITUTE – ETHIOPIA STRATEGY SUPPORT PROGRAM


Introduction

The Rural Urban Landscape in Ethiopia

• Of the estimated 73 million people living in Ethiopia (2007),

• 84% live in rural areas and with primarily income from agriculture

• 16% live in urban areas

• These are mostly located in the highland areas that comprise approximately 35% of Ethiopia‟s territory

• Urbanization rates differ according to methodologies and the database utilized:

• United Nations: 14.9% urban

• World Development Report:10.9% urban

• Central Statistical Agency of Ethiopia: 16% urban

• By comparison, the SSA average is 30% urban

• Ethiopia‟s non-agricultural sectors are also small relative to other countries in SSA

• In 2006/07 output of non-agricultural sectors contributed 54 % to GDP

• Non-agricultural sectors contributed 85 percent to GDP in SSA (and 75 percent of GDP in low income countries in SSA)



• The Central Statistical Agency defines urban areas as:• Localities greater than 2000 inhabitants

• Administrative capitals of regions, zones, and woredas

• Localities with at least 1000 people doing non-agricultural activities, and / or areas where the administrative official declares the locality to be urban

• Given these definitions, urban areas do not remain constant between census years

• With this study we provide a consistent definition of urban areas which can be compared over time, across countries and within national boundaries

Introduction



• In order to standardize urbanization measurements, we use

methodology developed by Uchida and Nelson (2009) which

incorporates a series of GIS data and analyses including:

• Travel time rasters,

• Population density

• Proximity to cities greater than 50,000

• We identify urban areas spatially using specific thresholds:

• A population density greater than 150 people per km2;

• Populations located within 1 hour travel time to a city of at

least 50,000 people.

• City centers of at least 50,000 people

Introduction



This study uses:

• GIS road network data from each Ethiopian census year (1984,1994,2007)

• Population data from each Ethiopian census year

• Population density grids:

• Landscan

• GRUMP (Global Rural and Urban Mapping Project, Columbia University)

• Other biophysical data to create a travel time grid:

• land cover, rivers, water bodies and elevation and slope

Data and Methods



In order to measure travel time to a major city:

Estimation of Travel Times

• A series of GIS layers are merged into a „friction layer‟ which represents the time required to cross each pixel

• Road type and class• Paved – all weather

• Paved – dry weather

• Gravel – all weather

• Gravel – dry weather

• Earth

• Waterbodies

• Landcover

• Slope

Data and Methods



Road network

Rivers and lakesLand cover

Slope

Cities

Data and Methods: data reclassification



Travel time

This friction layer is then used as an input into the “Cost

Distance” function in ArcGIS 9.2 in order to compute the

travel time in minutes from each pixel to the nearest

designated populated place.

In our study we analyzed travel time to cities of 50,000

people or more.

Road investments in Ethiopia greatly reduced travel time

between 1984 and 2007, especially in the highlands

Data and Methods



Travel time 1984



Travel time 1994



Travel time 2007



Once travel time is calculated to each major city for each census year, we are able to incorporate the cost distance raster into an agglomeration index measurement:

Urban population is determined using the criteria:

• Within an area of a population density of at least 150 people per square kilometer (calculated GRUMP and LandScan population density grids and adjusting for population growth

• Within a city of 50,000 people or within one hour travel time to a city of at least 50,000 people

Agglomeration Index

Data and Methods



GRUMP population density grid

GRUMP (Global Rural-

Urban Mapping Project)

human settlement data is

available and applying UN

growth rates, population

was estimated for 2000

Data and Methods: Population Density



LandScan population density grid

LandScan estimates the

large area population

density and spatially

allocates these data to key

infrastructure while

controlling for topography




Average of GRUMP and LandScan

Following the Uchida

and Nelson (2008)

methodology, we

average the population

density grids for

GRUMP and

Landscan in order to

take into account

specific features such

as urban areas and

road infrastructure.




Agglomeration Index 1984Results

In 1984, Addis Ababa and other

larger cities were primarily

confined to its city administrative

boundaries.

There were only a few cities with

greater than 50,000 people

Limited road networks and more

dispersed population characterized

the demographic landscape.


ResultsAgglomeration Index 1994

By 1994, Ethiopia‟s cities grew, and

the country‟s transportation network

expanded

Urban corridors were formed

between Sebeta in the southwest

and Bishoftu to the southeast, linking

to Nazareth

Population growth and improved

transportation infrastructure in

Shashamene and Awasa also

facilitated linkages to form an urban

network between Oromia and SNNP

regions.


ResultsAgglomeration Index 2007By 2007, urban linkages were

clearly visible throughout Oromia,

SNNP, and Amhara regions.

Addis Ababa expanded to connect

Sebeta and Bishoftu, and Asela in

the South.

Addis Ababa also connected to

Ambo in the west, and Debre

Berhan in the east

Hosaena linked to Sodo and

Shashamene

Linkages between Arba Minch and

Sodo were also forming

Jimma had grown into a

southwestern hub with opportunities

to link with Nekemte to the north.


• Since the previous census in 1994, new cities have been created, and economically viable cities have experienced large growth in population count and density

• Given that growth in the number of cities with at least 50,000 people mainly occurred in the four major regions, we find that increased urbanization rates are primarily confined to these regions

• The city administrative areas, of Addis Ababa and Dire Dawa, as well as Harari, a small urban region, experienced the greatest urbanization from 1984 to 1994.

• From 1994 to 2007, Addis Ababa and other urban areas expanded significantly into other regions.

• Given improved travel time between major cities, as well as increased population density on these corridors, urban areas in Ethiopia look more like networks in 2007 than the isolated communities typical of the 1984 urban landscape

Results



Larger cities have emerged over the 3 census years, especially

in Oromia, Amhara and SNNP regions

Cities in 1984* Cities in 1994 Cities in 2007

Region Over 20,000 Over 50,000 Over 20,000 Over 50,000 Over 20,000 Over 50,000

Tigray 1 1 5 1 10 3

Oromia 7 3 17 4 32 8

Amhara 5 3 7 3 18 7

SNNP 4 0 7 1 18 5

Gambella 0 0 0 0 1 0

Benishangul -

Gumuz

0 0 0 0 1 0

Harari 1 1 1 1 1 1

Dire Dawa 1 1 1 1 1 1

Addis Ababa 1 1 1 1 1 1

Somali 1 0 4 1 5 1

Afar 0 0 0 0 0 0

Number of cities over 20 and 50 thousand people during the census years

Results


Table 1: Agglomeration Index – Percent of people considered urban by region

Total Population

(thousands)

Percentage

Urban

Total Population

(thousands)

Percentage

Urban

Total Population

(thousands)

Percentage

Urban

Regions 1984 1994 2007

Addis Ababa 1,423 61.2 2,113 85.5 2,738 99.3

Afar 780 - 1,061 - 1,411 -

Amhara 10,686 2.0 13,834 3.7 17,214 7.5

Benishangul-Gumuz 351 - 460 - 671 -

Dire Dawa 158 20.3 252 58.2 343 66.3

Gambella 172 - 182 - 307 -

Harari 82 55.2 131 76.2 183 86.0

Oromia 14,016 1.7 18,733 4.6 27,158 9.2

SNNP 7,501 - 10,377 2.2 15,043 21.1

Somali 2,006 0.2 3,199 1.6 4,439 1.9

Tigray 2,692 2.0 3,136 3.8 4,314 8.0

Ethiopia 39,869 3.7 53,477 7.1 73,919 14.2

Results

• Addis Ababa (24%), Dire Dawa (38%) and Harari (21%) experienced the greatest urbanization from 1984 to 1994

• From1994 to 2007 the change in urban share was less than the previous decade for Addis Ababa (14 %), Dire Dawa (8%) and Harari (10%)

• All other regions experienced greater urbanization from 1994 to 2007


Population density and urban growth in 1994

Limited

urbanization (2.2%)

is present in SNNP

region in 1994


Population density and urban growth in 2007

City growth, as well

as more networked

infrastructure

increased

urbanization rates

in SNNP almost

20%


Percent population connected to a city of at least 50,000 people in 1994

Region Access < 1

hour

Access 1-3

hours

Access 3 - 5

hours

Access 5 - 10

hours

Access > 10

hours

Tigray 3.7 3.4 16.2 47.7 29.0

Afar - - - 5.6 94.4

Amhara 2.8 8.0 18.1 44.5 26.6

Oromia 5.3 7.7 20.6 36.7 29.8

Somali 8.0 - - 11.0 81.1

Benishangul-Gumuz - - - 11.2 88.8

SNNP 3.4 7.3 26.9 39.6 22.9

Gambella - - - - 100

Harari 100 - - - -

Addis Ababa 100 - - - -

Dire Dawa 100 - - - -

Ethiopia 8.4 6.4 18.2 36.0 31.0

Results

• In 1994, all of the inhabitants in Gambella region were more than 10 hours travel time to a city of at least 50,000 people

• Overall, 31% of the population in Ethiopia was more than 10 hours away from a major city

• In the four main regions, more than 50% of the population was over 5 hours travel time from a city


Travel Time: Percent point change in access to a city from 1994 to 2007

Region Access < 1 hour

Access 1 - 3 hours

Access 3 - 5 hours

Access 5 -10 hours

Access > 10 hours

Tigray 7.13 12.01 (3.72) 5.98 (21.39)

Afar - - - 4.11 (5.89)

Amhara 2.23 14.68 18.94 (12.49) (23.35)

Oromia 3.74 10.40 15.84 (8.88) (21.10)

Somali - - - 2.62 (2.61)

Benishangul-Gumuz - - - 17.91 (17.91)

SNNP 9.17 45.37 (14.59) (21.56) (18.39)

Gambella - - - - -

Harari - - - - -

Addis Ababa - - - - -

Dire Dawa - - - - -

Ethiopia 4.10 17.12 7.54 (9.93) (18.83)

Results

• No improvement was experience in Gambella region between 1994 and 2007

• Population over 10 hours in the main four regions improved by at least 18%

• Only 2.6 percent of the population in Somali region decreased travel time to under 10 hours over the 13 year period.


Difference in travel time to a city of at least 50,000 between 1994 and 2007

New gravel roads built between Kebri

Dehar and Gode; and Harar and Imi

eased access constraints in Somali

region considerably.

Although access has improved

considerably, populations remain very

remote (78 percent of the population

in Somali region is still further than 10

hours from a major city).

Extended evaluation of nascent

corridors between Jijiga and Kebri

Dehar, and between Harar – Imi –

Gode, could be undertaken to

understand the tradeoffs of investing

in these areas

Results



• Ethiopia has placed a primary emphasis on rural and agricultural led development; nonetheless, the country continues to urbanize and agglomeration economies are beginning to link and form corridors of economic growth.

• Improved transport within Ethiopia has facilitated greater mobility of capital, goods, and people, and incentivized population clustering along major transportation routes

• Improvements in road infrastructure between large cities, as well as increases in population density along these corridors, have increased urbanization rates (agglomeration indices) from 3.7 to 14 percent over the last 2 decades

• This dramatic transformation in the economic landscape is likely to continue, with important implications for future economic growth and public investments in infrastructure.

Conclusions


Technology

INSTITUTEUrbanization and Spatial Connectivity in Ethiopia: Urban Growth Analysis Using GIS