• No results found

Land use and land cover changes involve the transformation of the landscape. For example, the encroachment on the wetlands leads to increased incidences of floods. In addition, the freehold land tenure system in Kampala has accelerated the loss of land for cultivation in Kampala (Maxwell, 1994). Policy should focus on ensuring the farmers have secured land tenure to minimise rapid conversion of agricultural land to urban uses. Policymakers should target waste management policies, curb charcoal burning by encouraging the use of clean energy, and protect the wetlands.

96 3.6 Limitations of study

The supervised Landsat image classification to obtain land use and land cover (LULC) changes used in this chapter to produce LULC transition matrices have been generally found to produce relatively reliable landscape transformations. However, the accuracy of the LULC classification output is largely dependent on the satellite image quality and the resolution Landsat images used. The Landsat image quality is affected by atmospheric condition during the time of its capture, for instance, cloud cover has a great effect on the image quality.

Ideally, multi-temporal image assessment for comparison purposes would require using cloud- free images obtained on the same day of the month for the initial and latter year would lower the differences that can result from seasonal variability (rainy or dry). In this study, obtaining cloud-free images on the same day of the month for the initial and latter analysis year was a challenge. Therefore, images with up to 10% cloud cover were used which can potentially lower the out quality. Secondly, obtaining images on the same day of the month in both years was another challenge, for instance, the images used for Kampala LULC classification were captured between November and February. This also has a potential effect on the image output especially. Likewise, for Mbarara images were obtained between February and May. Fortunately, in Kampala, November to February generally lie in the same season and Mbarara February to May have similar weather condition, this minimised the impact, nevertheless lowered overall comparison.

The image resolution of 30m enables to capture LULC changes per 900 sq metre area which can more accurately be applied in peri-urban areas where it is more likely to find relatively uniform

97

land use over 900m. However, in an urban setup where standard plot size in Kampala and Mbarara measures 16 by 30.5 m (488 sq metres), LULC changes on these plots which are dominant as urban intensification continues in some cases cannot be captured.

The determining the principal signals of inter-category transition to identify the random or systematic landscape transition is that it only considers relative proportions of other categories at the initial time. This approach as aforementioned is based on an assumption that a given land use category should gain more from categories which were dominant in the landscape and again less from categories which comprised a small proportion of the landscape. However, this approach does not consider the relative positions of the categories, during urban growth, the proximity of the land category relative to urban built-up is very important. For example, a built- up category can gain more from a category nearest even if its relative proportion in the landscape at the initial time was less. This is one of the major limitations of using this approach in assessing systematic and random signals of LULC transition in an urban area.

In addition, the swapping change considers what a given category loses/gains to/from other categories, however, the limitation is that it only assess the quantity and does not consider the quality land gained or lost for a given category in the landscape. This is more so when we consider agricultural land, the lost land maybe or different productive as compared to what is gained in another part of the landscape as soil productivity is heterogeneous.

98 3.7 Conclusion

This paper has provided an account of urban growth in Uganda using Kampala and Mbarara regional centre as case studies. The built-up area in Kampala expanded by about 8 times between 1989 and 2015 while Mbarara increased by about 5 times between 2002 and 2016. Rapid urban growth not only leads to a loss of agricultural land, it also forces changes from savannah to grazing lands farther away from the city centre.

Significantly urban growth in both cities has led to the loss of agricultural land which indicates that the built-up area growth rate in both cities is usurping agricultural land. This is compensated by gains in agricultural land through the process of swapping with other categories, for example, savannahs and wetlands usually in peri-urban areas and surrounding rural areas. Thus, the loss of agricultural land is predominantly near the city centres and along the highways caused by their easy accessibility which acts as an attraction to urban development. This has led to systematic transition between agricultural land and built-up. Because of the absence of strict regulations to urban development and existence of a number of formal and informal land tenure systems in Uganda, as in most of the African countries, urban growth will continue to encroach into agricultural land.

In order to understand the implications of urban growth for agricultural production, there is the need to assess the quality of agricultural land lost to urban expansion in both cities. It is also necessary to examine the productivity of the new agricultural land vis-à-vis the lost land to understand the exact consequences of urban growth on agricultural production. Although

99

Kampala and Mbarara were chosen as case studies, the observable features of urban growth in these centres are extensible to most cities and urban centres in SSA. Therefore, this study is an impetus to further studies on the quality of urban and peri-urban agricultural land and its lost urban expansion and most importantly the overall impacts on urban food security in SSA.

The peri-urban zones closer to urban centres experience the immediate impacts of land demands from urban growth while the zone far from the city usually continues handling agricultural and natural resource products (Simon et al., 2004). Urban growth and development in smaller cities or peri-urban communities is increasingly an important component of land use change not only in the SSA but also in the rest of the developing countries (Nagendra et al., 2004). The rapidly changing conditions in smaller urban areas need to be monitored carefully if sustainable development is to be achieved as more and more agricultural land is expected to be converted to built-up (Vierich and Stoop, 1990, Yunlong and Smit, 1994, RUAF, 2010). Henderson (2002) observed that rapid growth of cities in Africa would negatively affect the quality of life in urban centres as a result of increased pressure on resources.

100 References

ALO, C. & PONTIUS JR, R. G. Detecting the influence of protection on landscape transformation in southwestern Ghana. Conference proceedings of the joint meeting of The Fifteenth Annual Conference of The International Environmetrics Society and The Sixth Annual Symposium on Spatial Accuracy Assessment in Natural Resources and Environmental Sciences. Portland ME. 17p, 2004.

ALO, C. A. & PONTIUS, R. G. 2008. Identifying systematic land-cover transitions using remote sensing and GIS: the fate of forests inside and outside protected areas of Southwestern Ghana. Environment

and Planning B: Planning and Design, 35, 280-295.

ANGEL, S., PARENT, J., CIVCO, D. L., BLEI, A. & POTERE, D. 2011. The dimensions of global urban expansion: Estimates and projections for all countries, 2000–2050. Progress in Planning, 75, 53- 107.

ATU, J. E., AYAMA, O. R., ENI, D. I., EJA, E. I. & ESIEN, O. E. 2012. The effects of urban sprawl on peripheral agricultural lands in Calabar, Nigeria. International Review of Social Sciences and

Humanities, 2, 68-76.

BEAUCHEMIN, C. & BOCQUIER, P. 2004. Migration and urbanisation in Francophone West Africa: An overview of the recent empirical evidence. Urban Studies, 41, 2245-2272.

BHASKARAN, S., PARAMANANDA, S. & RAMNARAYAN, M. 2010. Per-pixel and object-oriented classification methods for mapping urban features using Ikonos satellite data. Applied

Geography, 30, 650-665.

BIGSTEN, A. & KAYIZZI-MUGERWA, S. 1992. Adaptation and distress in the urban economy: a study of Kampala households. World Development, 20, 1423-1441.

BRADSHAW, T. K. & MULLER, B. 1998. Impacts of Rapid Urban Growth on Farmland Conversion: Application of New Regional Land Use Policy Models and Geographical Information Systems1.

Rural Sociology, 63, 1-25.

BRAIMOH, A. K. 2006. Random and systematic land-cover transitions in northern Ghana. Agriculture,

ecosystems & environment, 113, 254-263.

BRIGGS, J. 1991. The peri-urban zone of Dar es Salaam, Tanzania: recent trends and changes in agricultural land use. Transactions of the Institute of British Geographers, 319-331.

BRIGGS, J. & MWAMFUPE, D. 2000. Peri-urban development in an era of structural adjustment in Africa: the city of Dar es Salaam, Tanzania. Urban Studies, 37, 797-809.

BROWN, L. R. 1995. Who will feed China?: wake-up call for a small planet, WW Norton & Company. CHEN, J. 2007. Rapid urbanization in China: A real challenge to soil protection and food security. Catena,

69, 1-15.

CONGALTON, R. G. 1991. A review of assessing the accuracy of classifications of remotely sensed data.

Remote sensing of environment, 37, 35-46.

D’AMOUR, C. B., REITSMA, F., BAIOCCHI, G., BARTHEL, S., GÜNERALP, B., ERB, K.-H., HABERL, H., CREUTZIG, F. & SETO, K. C. 2016. Future urban land expansion and implications for global croplands. Proceedings of the National Academy of Sciences, 201606036.

DEL MAR LÓPEZ, T., AIDE, T. M. & THOMLINSON, J. R. 2001. Urban expansion and the loss of prime agricultural lands in Puerto Rico. AMBIO: A Journal of the Human Environment, 30, 49-54. DIJKSTRA, T. 2001. Export diversification in Uganda: developments in non-traditional agricultural

101

ELHADARY, Y. A. E., SAMAT, N. & OBENG-ODOOM, F. 2013. Development at the Peri-Urban Area and Its Impact on Agriculture Activities: An Example from the Seberang Perai Region, Penang State, Malaysia. Agroecology and Sustainable Food Systems.

ELNAGHEEB, A. H. & BROMLEY, D. W. 1994. Extensification of agriculture and deforestation: empirical evidence from Sudan. Agricultural Economics, 10, 193-200.

ERDAS 2013. ERDAS IMAGINE® 2011.

ERENSTEIN, O. 2006. Intensification or extensification? Factors affecting technology use in peri-urban lowlands along an agro-ecological gradient in West Africa. Agricultural Systems, 90, 132-158. FAZAL, S. 2000. Urban expansion and loss of agricultural land-a GIS based study of Saharanpur City,

India. Environment and Urbanization, 12, 133-149.

FOLEY, J. A., DEFRIES, R., ASNER, G. P., BARFORD, C., BONAN, G., CARPENTER, S. R., CHAPIN, F. S., COE, M. T., DAILY, G. C. & GIBBS, H. K. 2005. Global consequences of land use. science, 309, 570-574. GAR-ON YEH, A. & LI, X. 1999. Economic development and agricultural land loss in the Pearl River Delta,

China. Habitat International, 23, 373-390.

GODFRAY, H. C. J., BEDDINGTON, J. R., CRUTE, I. R., HADDAD, L., LAWRENCE, D., MUIR, J. F., PRETTY, J., ROBINSON, S., THOMAS, S. M. & TOULMIN, C. 2010. Food security: the challenge of feeding 9 billion people. science, 327, 812-818.

GOLD, C. S., KARAMURA, E. B., KIGGUNDU, A., BAGAMBA, F. & ABERA, A. M. 1999. Geographic shifts in the highland cooking banana (Musa spp., group AAA-EA) production in Uganda. International

Journal of Sustainable Development & World Ecology, 6, 45-59.

HAN, D., CURRELL, M. J., CAO, G. & HALL, B. 2017. Alterations to groundwater recharge due to anthropogenic landscape change. Journal of Hydrology, 554, 545-557.

HANDBOOK 1904. Handbook for East Africa, Uganda & Zanzibar. v.

HENDERSON, V. 2002. Urban primacy, external costs, and quality of life. Resource and Energy

Economics, 24, 95-106.

IMHOFF, M. L., BOUNOUA, L., DEFRIES, R., LAWRENCE, W. T., STUTZER, D., TUCKER, C. J. & RICKETTS, T. 2004. The consequences of urban land transformation on net primary productivity in the United States. Remote Sensing of Environment, 89, 434-443.

KCCA 2012. Updating Kampala Structure Plan and Upgrading the Kampala GIS Unit. preliminary report. 583.

KOMBE, W. J. 2005. Land use dynamics in peri-urban areas and their implications on the urban growth and form: the case of Dar es Salaam, Tanzania. Habitat International, 29, 113-135.

LAWRENCE, W., IMHOFF, M., KERLE, N. & STUTZER, D. 2002. Quantifying urban land use and impact on soils in Egypt using diurnal satellite imagery of the Earth surface. International Journal of Remote

Sensing, 23, 3921-3937.

LENNEY, M. P., WOODCOCK, C. E., COLLINS, J. B. & HAMDI, H. 1996. The status of agricultural lands in Egypt: the use of multitemporal NDVI features derived from Landsat TM. Remote Sensing of

Environment, 56, 8-20.

LERNER, A. M. & EAKIN, H. 2011. An obsolete dichotomy? Rethinking the rural–urban interface in terms of food security and production in the global south. The Geographical Journal, 177, 311-320. LUFAFA, A., TENYWA, M., ISABIRYE, M., MAJALIWA, M. & WOOMER, P. 2003. Prediction of soil erosion

in a Lake Victoria basin catchment using a GIS-based Universal Soil Loss model. Agricultural

systems, 76, 883-894.

LWASA, S. 2007. Population, urban development and the environment in Uganda: the case of Kampala city and its environs. Kampala: Makerere University.

LWASA, S. 2011. Sustainable urban development: managing city development in Uganda. Global

102

MAJALIWA, J., TWONGYIRWE, R., NYENJE, R., OLUKA, M., ONGOM, B., SIRIKE, J., MFITUMUKIZA, D., AZANGA, E., NATUMANYA, R. & MWERERA, R. 2010. The effect of land cover change on soil properties around Kibale National Park in South Western Uganda. Applied and Environmental

Soil Science, 2010.

MANANDHAR, R., ODEH, I. O. & PONTIUS, R. G. 2010. Analysis of twenty years of categorical land transitions in the Lower Hunter of New South Wales, Australia. Agriculture, ecosystems &

environment, 135, 336-346.

MAS, J.-F. 1999. Monitoring land-cover changes: a comparison of change detection techniques.

International journal of remote sensing, 20, 139-152.

MAXWELL, D. G. 1994. The household logic of urban farming in Kampala. Cities feeding people: an

examination of urban agriculture in East Africa [Egziabher, AG; Lee-Smith, D.; Maxwell, DG; Memon, PA; Mougeot, LJA; Sawio, CJ]. 47-65.

MAXWELL, D. G. 1995. Alternative food security strategy: A household analysis of urban agriculture in Kampala. World Development, 23, 1669-1681.

MERTENS, B. & LAMBIN, E. F. 2000. Land‐cover‐change trajectories in southern Cameroon. Annals of the

association of American Geographers, 90, 467-494.

MEYER, W. B. & TURNER, B. L. 1992. Human population growth and global land-use/cover change.

Annual review of ecology and systematics, 23, 39-61.

MUBEA, K. & MENZ, G. 2012. Monitoring land-use change in Nakuru (Kenya) using multi-sensor satellite data.

MUNDIA, C. & ANIYA, M. 2005. Analysis of land use/cover changes and urban expansion of Nairobi city using remote sensing and GIS. International Journal of Remote Sensing, 26, 2831-2849.

NAGENDRA, H., MUNROE, D. K. & SOUTHWORTH, J. 2004. From pattern to process: landscape fragmentation and the analysis of land use/land cover change. Agriculture, Ecosystems &

Environment, 101, 111-115.

NAUGHTON-TREVES, L., KAMMEN, D. M. & CHAPMAN, C. 2007. Burning biodiversity: woody biomass use by commercial and subsistence groups in western Uganda’s forests. Biological conservation, 134, 232-241.

NDUMU, D., BAUMUNG, R., HANOTTE, O., WURZINGER, M., OKEYO, M., JIANLIN, H., KIBOGO, H. & SOLKNER, J. 2008. Genetic and morphological characterisation of the Ankole Longhorn cattle in the African Great Lakes region. Genetics selection evolution, 40, 467-490.

NEMA 2001. State of environment report for Uganda 2000/2001. NEMA, Kampala, Uganda.

ODEH, I. O. & ONUS, A. 2008. Spatial analysis of soil salinity and soil structural stability in a semiarid region of New South Wales, Australia. Environmental management, 42, 265-278.

OKOT-OKUMU, J. & NYENJE, R. 2011. Municipal solid waste management under decentralisation in Uganda. Habitat International, 35, 537-543.

OMOLO-OKALEBO, F., HAAS, T., WERNER, I. B. & SENGENDO, H. 2010. Planning of Kampala City 1903— 1962: The Planning Ideas, Values, and Their Physical Expression. Journal of planning history, 9, 151-169.

PENDER, J., NKONYA, E., JAGGER, P., SSERUNKUUMA, D. & SSALI, H. 2004. Strategies to increase agricultural productivity and reduce land degradation: evidence from Uganda. Agricultural

economics, 31, 181-195.

PLAUT, T. R. 1980. Urban expansion and the loss of farmland in the United States: Implications for the future. American Journal of Agricultural Economics, 62, 537-542.

PONTIUS, R. G., SHUSAS, E. & MCEACHERN, M. 2004. Detecting important categorical land changes while accounting for persistence. Agriculture, Ecosystems & Environment, 101, 251-268.

POTTS, D. 2009. The slowing of sub-Saharan Africa's urbanization: evidence and implications for urban livelihoods. Environment and Urbanization, 21, 253-259.

103

POTTS, D. 2012. Whatever Happened to Africa's Rapid Urbanisation?, Africa Research Institute (ARI). PRABHA, K. 1993. Urban Agriculture in the Formal Economy and Land Use Planning in Kampala, Uganda.

New York University, North York, Canada.

PRETTY, J., TOULMIN, C. & WILLIAMS, S. 2011. Sustainable intensification in African agriculture.

International journal of agricultural sustainability, 9, 5-24.

QI, L., SÖDERLUND, L., PEILIN, W. & JUAN, L. Cultivated land loss arising from the rapid urbanization in China. Proceedings SUSDEV-China Symposium: Sustainable Agroecosystem Management and Development of Rural-Urban Interaction in Regions and Cities of China, 2005. 313-27.

RATTRAY, A., IERODIACONOU, D., MONK, J., VERSACE, V. & LAURENSON, L. 2013. Detecting patterns of change in benthic habitats by acoustic remote sensing. Marine Ecology Progress Series, 477, 1- 13.

RAWAT, J. & KUMAR, M. 2015. Monitoring land use/cover change using remote sensing and GIS techniques: a case study of Hawalbagh block, district Almora, Uttarakhand, India. The Egyptian

Journal of Remote Sensing and Space Science, 18, 77-84.

RUAF 2010. The growth of cities in East-Africa: Consequences for urban food supply. Accessed on

http://www.globalhort.org/.../VC7%20Issue%20Paper%20Final%20Version, November 2013, 35.

SCHUSTER, C. 2004. A note on the interpretation of weighted kappa and its relations to other rater agreement statistics for metric scales. Educational and Psychological Measurement, 64, 243- 253.

SETO, K. C., WOODCOCK, C., SONG, C., HUANG, X., LU, J. & KAUFMANN, R. 2002. Monitoring land-use change in the Pearl River Delta using Landsat TM. International Journal of Remote Sensing, 23, 1985-2004.

SHALABY, A. & TATEISHI, R. 2007. Remote sensing and GIS for mapping and monitoring land cover and land-use changes in the Northwestern coastal zone of Egypt. Applied Geography, 27, 28-41. SIM, J. & WRIGHT, C. C. 2005. The kappa statistic in reliability studies: use, interpretation, and sample

size requirements. Physical therapy, 85, 257.

SIMON, D., MCGREGOR, D. & NSIAH-GYABAAH, K. 2004. The changing urban-rural interface of African cities: definitional issues and an application to Kumasi, Ghana. Environment and Urbanization, 16, 235-248.

SINGH, A. 1989. Review article digital change detection techniques using remotely-sensed data.

International journal of remote sensing, 10, 989-1003.

TAN, M., LI, X., XIE, H. & LU, C. 2005. Urban land expansion and arable land loss in China—a case study of Beijing–Tianjin–Hebei region. Land use policy, 22, 187-196.

THEOBALD, D. M. 2001. LAND‐USE DYNAMICS BEYOND THE AMERICAN URBAN FRINGE*. Geographical

Review, 91, 544-564.

THOMAS, B. E. 1970. On the growth of African cities. African Studies Review, 13, 1-8.

TORQUEBIAU, E. 1992. Are tropical agroforestry home gardens sustainable? Agriculture, ecosystems &

environment, 41, 189-207.

UBOS 2002. Uganda population and housing census. Uganda Bureau Of Statistics.

UN-HABITAT 2008. The state of African cities 2008: a framework for addressing urban challenges in Africa. Nairobi: UN Habitat.

UN-HABITAT 2010. State of African Cities 2010. Governance, Inequalities and Urban Land Markets.,

UNEP, Nairobi.

UN-HABITAT 2012. Mbarara municipality urban profile. United Nations Human Settlements Programme.

Accessed June, 12, 2013.

UN 2016. The World’s Cities in 2016.

http://www.un.org/en/development/desa/population/publications/pdf/urbanization/the world s cities in 2016 data booklet.pdf.

104

VAN DEN BRINK, B., HILLER, S. & VAN DER VALK, O. 2010. Capacity building floriculture Uganda: Project progress report 2009. Nuffic.

VERMEIREN, K., ADIYIA, B., LOOPMANS, M., TUMWINE, F. R. & VAN ROMPAEY, A. 2013. Will urban farming survive the growth of African cities: A case-study in Kampala (Uganda)? Land use policy, 35, 40-49.

VERMEIREN, K., VAN ROMPAEY, A., LOOPMANS, M., SERWAJJA, E. & MUKWAYA, P. 2012. Urban growth of Kampala, Uganda: Pattern analysis and scenario development. Landscape and Urban

Planning, 106, 199-206.

VIERICH, H. & STOOP, W. 1990. Changes in West African savanna agriculture in response to growing population and continuing low rainfall. Agriculture, Ecosystems & Environment, 31, 115-132. VINING, D. R., PLAUT, T. & BIERI, K. 1977. Urban encroachment on prime agricultural land in the United

States. International Regional Science Review, 2, 143-156.

WASIGE, J. E., GROEN, T. A., SMALING, E. & JETTEN, V. 2013. Monitoring basin-scale land cover changes in Kagera Basin of Lake Victoria using ancillary data and remote sensing. International Journal of

Applied Earth Observation and Geoinformation, 21, 32-42.

XIE, Y., MEI, Y., GUANGJIN, T. & XUERONG, X. 2005. Socio-economic driving forces of arable land conversion: A case study of Wuxian City, China. Global Environmental Change, 15, 238-252. YANG, X. & LO, C. 2002. Using a time series of satellite imagery to detect land use and land cover

changes in the Atlanta, Georgia metropolitan area. International Journal of Remote Sensing, 23, 1775-1798.

YUNLONG, C. & SMIT, B. 1994. Sustainability in agriculture: a general review. Agriculture, Ecosystems &

Reconstruction of pre-urban soil patterns under expanding megalopolis in Sub-Saharan Africa: a case study of the Greater Kampala Metropolitan Area (GKMA)

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Abstract

Most of the urban growth in developing countries is occurring on productive soils. Yet there is a lack of detailed baseline soil information that can facilitate the assessment of the impact of urbanisation on the loss of quality soils. The current soil maps in most African countries are rather old with little details. The biggest hindrance to updating and improving the soil information in such a setting is the high costs of the required detailed soil survey, in addition to complication caused by the loss of natural soils to urban development (Urbanisation leads to continuous alteration of the soil which makes it difficult to classify it classify). Therefore, this