Assesement of resilience of Kiwunya channel to flash flooding
Abstract
Of sub-Saharan Africa, Kampala is a prototypical class of city characterised by rapid polarised population growth with basically an informal development planning systems of regulatory frameworks based on colonial inheritance or inflexible instrument run under precarious management systems (African planning Association,2014).
Known to be a city of “a thousand hills” amidst undulations of ground scenery, it is made up of a number of flood zones (Chereni,2016) with its drainage systems which are inadequately developed and maintained despite recent major investments in the system (Runya, Qigui and Wei,2015) which have mitigated existing problems and as such, it has contributed to aggravating local flooding (Lwasa, 2013). The suburbs of Kasubi and Kikoni is a refuge to more than 60% of Makerere University students, hence this sets up a settlement pattern that exerts considerable pressure on the existing urban drainage system failure and of such it leads to a range of environmental, economic and human instability disasters such as catastrophic flooding, damage of property, critical infrastructural damage and spread of diseases (Romang et al,2011).Traditionally, the different strategies to curb down the adverse effects of flash flooding has been based on the economic and technical aspects involving between the civil society, private sector and government (Wiering et al,2017) and little focus has been directed towards balancing the urban hydrology system and sustainable development as risk management approach in the Kampala Master plan (AFPM,2007a,2007b,2008,2012 & KCCA,2017) but flash flooding failed to be solved in lowland (Mhonda,2013).
In recent years climatic change has brought about an unanticipated volume rises of water levels(Haung,2018) though this has had neglectable effect on the drain channels around Kampala as compared to the result of extreme conditions of rain fostering foresightedness in establishing the partnerships to jointly find solutions for the recurring flash floods(Priest & Mees,2016) in Greater Kampala with attributions of the causes to an insufficient, dilapidated and poorly managed drainage systems, combined with poor solid waste management, particularly of plastic waste, resulting in clogged drainage channels(PAP,2022). Flash flood hazard is expected to increase based on its frequency and severity, arising from the impacts of global change on climate, severe weather in the form of heavy rains and river discharge conditions (Jehanzaib,2022). Two of the main factors responsive in this effect are the human induced factors for instance rapid urbanization with extreme increase in migration thus rapid spatial change in the land use and land. Secondly, are the natural factors that consist of lithology, terrain, torrential rainfall, and natural drainage (river) system.