Suchergebnisse

Two main challenges facing humanity today are sustainable development and avoidance of human-induced climate change. In many ways these two threaten human civilisation and development and the very existence of life on earth. These words are mentioned in UN conferences; in professional bodies' workshops; in the corridors of government departments; in school classrooms and among the general public. There is also extensive amount of literature on the same subjects. Many recognise the problems and try to look for solutions. Climate change has impacted negatively on both rural and urban landscapes. River corridors uniquely cross through many environments and ideally should exhibit same character wherever it crosses irrespective of adjoining land uses. However. where it crosses urban landscapes, places of intense and varied land uses, human interference and abuse is most witnessed and recognisable. As more and more people migrate to urban areas, the situation is bound to get worse. New ways of planning and design of this landscape, especially in the face of adverse effects of climate change, should be sought. This dissertation seeks to be part of this endeavour to propose methods of how the urban river landscape can or should be moulded to reduce the impact of climate change first on its ecological integrity and balance and secondly to its socio-economic and cultural aspects to urban dwellers.

Abstract
Aquatic macroinvertebrates (AM) have a special ecological niche in the functionality of urban wetland communities. This class of animals also play a crucial role in urban environmental and water quality assessments through bio-indication and bio-monitoring. However, the continued loss and isolation of palustrine wetlands, driven by urbanization and other anthropogenic processes, result in reduced biodiversity of macroinvertebrate communities. This study sought to determine how palustrine wetland configuration affect biodiversity structure of AM in Nairobi. Wetland configuration attributes of area, perimeter, shape, and edge were examined. For wetland biodiversity, family richness and Shannon index of diversity were assessed. It was hypothesized that wetland configuration affects the biodiversity of AM. From a population of 303 wetlands, this study used heterogeneous sampling to identify and investigate 31 palustrine wetlands spread across the city of Nairobi. Data were collected using observation checklists and archival review. Correlations and multiple regression analysis were performed in IBM SPSS Statistics 21. It was found that wetland configuration significantly affected the biodiversity of AM at R2 = 0.587, F (6, 23) = 5.447, P < 0.001. The study highlights the need to identify the optimum wetland configuration pattern for the biotic enhancement and conservation of AM in palustrine wetland habitats in urban landscapes. Consequently, the ecological stability of urban wetland communities, their accessibility, as well as the innate affection by urban residents, become a desired conservation goal in urban planning and design.