An impact assessment of population density on environmental quality in unplanned settlements: A case of Kibera

Abstract

The main objective of this study was to systematically investigate the inherent environmental conditions and the effects of population density on the environment in the low income settlement of Kibera. The nature and extent of pollution in the area vis a vis density was assessed. The guiding premise of the study was that large population numbers in Kibera has resulted into an increase in the number of housing structures and therefore resulting to both high population and housing densities. These two densities through the pursuit of socio-economic and cultural actuality by the community in question have contributed to negative effects on the quality of the environment within the area. To meet the objectives, an appraisal was done on the number of persons per household, per acre and number of housing units per acre, the existing amount of open space available per household for waste collection, storage, disposal and/or treatment, waste generation, collection, disposal systems, management Systems, and the nature and type of existing sewage disposal system and subsequent problems. Environmental quality was the dependent variable, while the independent variables were waste generation, collection, disposal, open space, persons per are/household, housing units per acre sewage disposal system an drainage system. The

components of environmental quality included, waste treatment, smell and noise, visual quality of houses and open spaces and streets, accessibility to water and public utilities, ease of movement, and general cleanliness of the surrounding. The study found out that the population of Kibera is one of the fastest growing among the sub-localities of Nairobi city and it is one of the spatially highly densified areas of Nairobi, second after Mathare Valley. Kibera currently has a population of well over 200,000 with a density of 70,000 per square kilometre. Population density of Kibera grows at a rate of 10 percent per annum and the population grows at a rate of 7 percent per annum. The population is predominantly young and is male oriented. The mean household size was 4. Migration contributes significantly to the growth of Kibera more than natural growth. Land in Kibera is government owned. Majority of the houses belonged to absentee land lords. Land use in Kibera is poorly coordinated and unplanned. Over 90 percent of land is devoted to residential use, and there is no land set aside for collective use or as open spaces. All the housing units took the form of back to back housing blocks built with mud, cement, timber and iron sheets and contained between 5 and 20 room units. Distances between blocks varied from 1 feet to 5

feet apart. The houses varied in sizes ranging frorn 64 to 200 square feet. The structure density was as high as 428 housing units per acre. The houses were predominantly non-durable types given the construction technology and materials used. There is a lack of infra structural services within Kibera. There were no roads apart from simple paths and corridors. There is no adequate water supply and sewerage and access to water was very limited. ~ problem of waste disposal emerged as one of the serious environmental problems. The physical environmental pollution in Kibera is mostly generated by. different forms of solid waste. Regarding environmental management, irresponsibility was noted. There was no organized garbage management system among the residents and environmental concern was very low. The study recommends a comprehensive slum upgrading programme for Kibera which is to include the provision of infrastructure and socially acceptable housing, adequate access to public utilities and a healthy habitable environment.