Air Transport in Kenya: an Analysis of Domestic and International Airline Networks

Abstract

The main objective of this study is to describe, analyse and explain the networks of both domestic and international airlines in Kenya and to examine the relationship between domestic air transport and national development. Four main lines of investigation are pursued in the study. These are: (a) The spatial structure of air transport networks in Kenya. This involves a detailed historical survey of the evolution of domestic and international air transportation networks from as far back in time as possible. The main stages identified are compared with the "ideal-typical sequence model" developed by Holsman and Crawford in 1975. (b) The causal factors that have influenced the evolution of air transport network in Kenya. The main physical and socio-economic factors influencing the evolution of the domestic air transport in the country are identified and discussed. (c) The patterns of air passengers and commodity flows. (d) The relationship between air transport growth and spatial pattern of development in Kenya. An index of development status is constructed to measure the spatial variation in human welfare in all the districts of Kenya. The index is used as a basis for ranking, comparing and classifying districts according to their development status. The relationship between Composite Index of Development Status (CIDS) and indicators of air transport growth is examined.

In the present study, four Null Hypotheses were formulated and tested. They are that: (a) there is no significant difference between the stages of growth of the Kenyan air transport network and the ones predicted by the Holsman-Crawford "ideal typical sequence model" of air transport growth. (b) the volume of air passenger traffic does not vary with sizes of places and the distance between them. (c) the volume of cargo freight does not vary with sizes of places and the distances between them. (d) there is no significant relationship between the development of air transport and the spatial patterns of development.

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The Null Hypotheses were explored using several statistical techniques, namely, the graph theoretical techniques, multiple linear regression and correlation analysis and the Common Factor Analysis (CFA). Graph theoretical indices were computed for the Kenyan domestic air transport network for a period of over fifty years, since 1938. The graph theoretical indices showed whether the country's domestic air transport system has been growing over time or not. A "Matrix Powering Technique" of the graph theoretical approach was used to show whether the accessibility surface of the domestic air transport network was becoming highly peaked or polarised over time. Multiple Linear Regression and Correlation Analysis was applied to both international air passenger and commodity flow traffic data. Bivariate correlation analysis was used to measure the strength of the relationship between air transport growth and the spatial patterns of development. Stepwise multiple regression and correlation analysis was used to corroborate the results of the bivariate correlation analysis, confirming that there is a significant relationship between air transport growth and the spatial pattern of development. The main findings of the study are also discussed. Some of these are: (a) that the general trends of Kenya's domestic air transport growth correspond to those proposed in the Holsman- Crawford "ideal-typical sequence model" of air transport growth. The present study has established that the domestic air transportation network has evolved through three main stages comparable to the first, second and third phases of the Holsman­ Crawford Model. This is the first time this theoretical model has been tested anywhere in the world outside north western Australia where it was first developed. This fmding would seem to confirm that the model could apply to other areas too. (b) the application of multiple linear regression and correlation analysis to the international air passenger and

commodity flow data revealed that: (i) distance was a very important explanatory factor accounting for 30 % of the total variation in the volume of air passenger traffic between Nairobi and other international air hubs. (ii) GDP was the most important explanatory factor accountingfor 14% of the total variation in the volume of commodity shipment. -- xx

The study has made some important contributions to transport geography. Some of these include: (a) the application of a variant of Nystuen and Dacey's technique of Dominant Flow Analysis, called simple linkage analysis. The application of simple linkage analysis to Kenya's domestic air passenger flow data in order to identify the dominance-dependency nodal regions of air passenger interaction is an important contribution to the methodology in flow analysis. Most of the previous studies have used the original version of Nystuen and Dacey's Dominant Flow Analysis. Simple linkage analysis is a much better method of portraying the nodal structures of a network than Nystuen and Dacey's Dominant Flow Analysis. (b) the construction of a new composite index for measuring spatial variation in human welfare at the sub-national (district) level. This is one of the most important contributions made by the study. The new composite index of development status (CIDS) is a robust and versatile measure that provides multi­ dimensional insights about spatial variation of development at the sub-national (district) level.

Finally, this study recommends that, to promote a balanced development in the country, an integrated transport network should be established. This can be achieved through strategic planning of domestic air services with special emphasis on their integration with surface transportation modes such as roads and railways .