Land Use Change and Environmental Sustainability: the case of Lagos Metropolis

I. I. C. Nwokoro1 and S. O. Dekolo2 1Department of Urban and Regional Planning,

University of Lagos, Nigeria 2 Department of Urban and Regional Planning,

Lagos State Polytechnic, Nigeria

7th International Conference on Urban Regeneration and Sustainability7 - 9 May, 2012Ancona, Italy

SUSTAINABLE CITY 2012

This presentation examines Spatio-temporal trends in land use and land cover changes in the Lagos Metropolitan region, especially the loss of forest resources and agricultural land to urban development.

The dynamics of land use change and its impact on the environmental sustainability will be discussed.

Finally recommendations for sustainable land use and practices are outlined.

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Presentation Overview

Cities expansion in developing countries is characterized by sporadic growth and sprawling development especially in rapidly growing metropolitan regions which has resulted in problems like climate change, resource depletion and diminution of agro-ecological and rural lands.

Studies show that developing countries have much faster urban population growth than the developed world. In the 1950’s less than 20% of people in developing countries lived in cities, however, the proportion increased to 40% in year 2000. It is projected that about 60% the developing world will live in urban areas in 2030.

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Introduction

Lagos metropolis is a continuous built area spanning over 153,540 hectares of land comprising virtually all the Local Government Areas of Lagos State and four LGAs (i.e., Sagamu, Owode, Ifo and Ado-Odo/Otta) in the neighbouring Ogun State.

It was ranked by United Nations (World Urbanization Prospects, 2007) as 9th among the 28 current and prospective megacities in the world with a standard of living score of 19%.

The city has experienced tremendous spatial and demographic growth which has led to continuous loss of forest and agricultural land to built-up areas.

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

The Study Area: Lagos Metropolis

City 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2007 2010 2015 2020

Abuja 23 29 48 77 125 204 330 526 832 1315 1576 1994 2558 2971

Benin City 83 113 163 233 335 480 689 845 975 1124 1190 1302 1520 1755

Ibadan 570 668 809 980 1186 1436 1739 1993 2236 2509 2628 2835 3270 3752

Ilorin 179 222 268 323 389 457 515 580 653 735 771 835 970 1123

Kaduna 99 173 266 408 628 853 961 1083 1220 1375 1442 1560 1807 2083

Kano 229 343 542 855 1350 1861 2095 2360 2658 2993 3140 3393 3914 4487

Lagos 762 1135 1414 1890 2572 3500 4764 5966 7233 8767 9466 10572 12403 14134

Maiduguri 105 156 216 300 416 531 598 673 758 854 896 969 1125 1301

Ogbomosho 247 333 378 428 485 549 622 704 798 904 951 1031 1199 1386

Port Harcourt 135 198 266 358 482 604 680 766 863 972 1020 1104 1280 1479

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Population Growth of Lagos Metropolis

Source: Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat, World Population Prospects: The 2006 Revision and World Urbanization Prospects: The 2007 Revision, http://esa.un.org/unup,

Thursday May 03, 2012; 11:09:22 AM.

Nigerian Cities with Population 750,000 or More in 2007 (1960-2020) (In Thousand)

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Urban Growth of Lagos Metropolis

1 2 3 4 5 6 7 8 9 10 11 12 13 140

2000

4000

6000

8000

10000

12000

14000

16000

Abuja 2971

Benin City 1755

Ibadan 3752

Ilorin 1123

Kaduna 2083

Kano 4487

Lagos 14134

Maiduguri 1301Ogbomosho 1386Port Harcourt 1479Zaria 1293

Nigerian Cities with Poplation 750,000 or More in 2007

PO

PU

LATIO

N (

‘000)

Source: Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat, World Population Prospects: The 2006 Revision and World Urbanization Prospects: The 2007 Revision, http://esa.un.org/unup,

Thursday May 03, 2012; 11:09:22 AM.

Urban Growth of Lagos Metropolis

Spatial Expansion of Lagos City (1900-1984)*

2006

The city grew from a small fishing settlement in Lagos Island, which later became the seat of the British Colonial government in 1861. The censuses 1871 and 1911 shows that the city’s population had doubled from 28,520 to 73,770; by 1963 the population has increased to 1.4 Million people with its urban population put at 46% .The following census of 1991 puts its population at 5.6 Million with its urban areas accounting for 92%. This is quite high compared to previous censuses. In the 2006 census, the population rose to 9.1 million with its urban development extending beyond the state boundaries and making it a Megacity and one of the largest conurbations in the world.

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Land use and land cover changes due to city expansion have serious ecological repercussions and pose a great deal of challenge to environmental sustainability at local and global scales. It is a major driving force of global environmental change, which affects the earth systems.

Prevailing global changes linked to deforestation, desertification, biodiversity loss, food insecurity, climate change, carbon emission etc, are consequences of unsustainable use of land or unsustainable practices.

Sustainability was defined by the Bruntland Commission (1987) as the “ability to meet today’s global economic, environmental, social needs without compromising the opportunity for future generations to meet theirs”.

Land use change is driven by Biophysical, economic, social and Institutional forces. However, these forces must be kept within environmental tolerable limits.

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Land Use Change + Sustainability Trajectory

Land Use ChangeDrivers

Environmental (Biophysical)

Economic

Social

Institutional

Sustainability Dimensions

Environmental

Economic

Social

Institutional

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Land Use Change + Sustainability Trajectories

In most change detection studies, supervised and unsupervised methods of classifications are used. The former using training samples, samples of known identity to classify pixels of unknown identity, while t using training samples, samples of known identity to classify pixels of unknown identity, while the later identifies natural groups, or structures, within multispectral data.

In this study of Land Use Change of Lagos Metropolis, Multitemporal Landsat satellite images were used and classified using an unsupervised method.

The study area was classified into seven and maps were generated after re-classification based on natural groups germane to the study. The final output classes were: major urban, minor urban, forested freshwater swamps; riparian forests; cultivated farmlands, water bodies and no data

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Methodology Used

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Workflow of Study

0 6 12 18 243

Kilometers

Land Use Pattern 1990 Land Use Pattern 2006

0 5 10 15 202.5

Kilometers

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Change Analysis: 1990-2006

LULC Classification

1990 2006

% Change

Remarks

Area (ha) % Area (ha) %

Waterbody 27423 21.54 25754 20.23 -1.31Decrease

Riparian Forest 43272 33.99 19798 15.55 -18.44

Decrease

Forested Freshwater Swamp 9237 7.26 6612 5.19 -2.07

Decrease

Cultivated Farmlands 7206 5.66 14111 11.09 +5.43

Increase

Minor Urban 7071 5.56 8106 6.37 +0.81Increase

Major urban 32611 25.62 52908 41.57 +15.95Increase

No Data 469 0.37 0 0 N.A.Not Applicable

127289 100 127289 100

There is a continuous urban growth beyond the administrative boundaries of the city giving a serious challenge in fiscal management and responsibilities.

The study also shows that there was an overall 30% loss of agro-ecological zone, with the built up areas (major and minor urban land uses) rising from 31% to 48% within the study period.

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Findings and Discussion

There was a loss of 1.31% of the water bodies during the study period. This may be due to continuous reclamation and sand filling of water fronts, swamps and the Lagos lagoon for residential development by government and private developers.

There is also loss of forest reserves and freshwater swamps, which reduced by approximately 20% land to built-up urban development

The study also reveals a 5% rise in cultivated farmland.

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Findings and Discussion

The Land use change study has shown that between 1990 and year 2006, there was significant decrease of over 20% of the forest resources and ecological sensitive areas of the metropolis to urban development.

The research established that remote sensing and GIS are viable tool for natural resource management in the developing countries as it provides insight to the current trend in resource depletion, deforestation and loss of biodiversity in the ever growing city.

There is a need to urgently address the depletion of the forest and water resources in Lagos Metropolis.

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Conclusion

There is need for timely and accurate data management of land based resources in our cities

There is need for implementation of spatial technologies in government agencies responsible for environmental management and city management.

It is also suggested that GIS technology be adopted by land managers in the city’s municipalities or local government councils as well as other government and non-governmental agencies dealing with land use management.

Spatial Data infrastructure need to be put in place to encourage data sharing in our cities.

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Recommendations and Policy Implications

This research was conducted at the Lagos Urban Observatory domiciled at the Department of Urban and Regional Planning, University of Lagos.

Further work being done includes determining the drivers of these changes and modeling the future changes of the Megacity. It is hoped that these findings will be presented in future conferences.

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

Further Work

Well informed land use decisions will enhance sustainable development.

Thank You

*The image Spatial Expansion of Lagos City (1900-1994) was downloaded from Josephine Abiodun’s work at URL:-

http://archive.unu.edu/unupress/unupbooks/uu26ue/uu26ue0i.htm

I.I.C. Nwokoro & S. O. Dekolo, University of Lagos, Nigeria

A Final Word