Influence of dyke characteristics on human activities of the community in lower river Nyando basin, Kenya

Abstract

Construction of dykes along several rivers in the world is one of the practical methods to minimize risks of flood events on riparian communities. Globally, one eighth of the world‟s settlement area is vulnerable to flooding despite the efforts placed by governments like Netherlands, Vietnam, Nigeria and Kenya of constructing dykes to protect riparian communities. The dykes minimize flooding impacting positively and/or negatively on the human activities of the riparian community. Ranking high among such impacts is interference of human activities like food crop production, fishing, and settlement among other activities. In Nyando basin, Kenya, dykes were constructed to minimize flood impacts on human activities in the floodplain. The dyke characteristics change silt deposition on farmlands, provide security changing settlement and housing structures, and fish breeding grounds and fish abundance. Despite these dynamics, some farmers now use fertilizers as a new way of coping with the dykes. Several researches have been done in Kenya on the effects of floods to human activities. However, there is no clear documented link between dyke characteristics like period of existence, length and height and the influence on human activities like food crop production, fishing and settlement. The dykes in Nyando have reduced flooding in the region, however, it is not clearly understood how the dyke characteristics influence human activities like food crop farming, fishing and settlement patterns and housing. Therefore, the purpose of this study was to examine the influence of dyke characteristics on human activities of the community in Lower River Nyando basin in Kisumu County. The specific objectives of the study were to: assess the influence of dyke characteristics on food crop production, examine the influence of dyke characteristics on settlement patterns and housing and analyze the influence of dyke characteristics on fishing. This study was guided by Program Theory. A Descriptive cross sectional research design was used. The study population comprised of 34,460 households. A minimum sample size of 384 household heads was obtained by the Krejcei et al formula. Households were selected using simple random sampling while purposive sampling was used to identify key-informants. Primary data was obtained by the administration of questionnaires, key informant interviews, Focus Group Discussions, Observation, and Photography. Secondary data was obtained from published and unpublished reports on dykes and ward-level data reports. Quantitative data was analyzed using Descriptive and Inferential Statistics. Qualitative data was analyzed by coding and organization of data into themes and sub-themes. The results from the multiple coefficients of determination (R2) indicated that 45.4% (R2 = .454, p = .039) of the variation in the general crop yield was explained by the combined change in Dyke Characteristics. Similarly, 66.1% (R2 = .661, p = .046) of the variability in Human settlement (number of Houses) was possibly attributed to the overall variation in Dyke Characteristics. Meanwhile 31.8% (R2 = .318, p = .034) of the change in number of fish caught per year was statistically significant and could generally be explained by the change in Dyke Characteristics. The findings of the study can enhance the understanding and knowledge of the influence of dykes on human activities.