Author: Tamer Almaaitah
Sudan, like many other countries, suffers frequent flooding because of the global climate change. The situation is worse in the capital, Khartoum, where the city has been experiencing rapid urbanisation and construction. Flash floods can have dangerous health and economic effects. In 2018, at least 23 people have been killed and 61 have been injured in Sudan during extreme floods. It is estimated that more than 8900 families have become homeless after their properties were damaged by floods . Hydrologically speaking, urbanisation is one of the leading causes of floods. The loss in pervious surfaces and the introduction of artificial drainage lead to a reduction in infiltration which overall increases surface runoff and cause a flood.
It is undoubtedly clear that there is a need for modern flood management strategies that can effectively reduce the devasting impacts of flood water within Sudan’s cities. Low Impact Development (LID) practices, also known as Sustainable Drainage Systems (SuDS) in the UK, are nature-based stormwater management solutions that mimic the natural disposal of surface runoff. These systems mitigate the changes of both quantity and quality of urban runoff caused through changes to land use. LID technologies are designed to reduce stormwater volume, peak flows, and/or nonpoint through evapotranspiration, infiltration, detention, and filtration. Therefore, it is crucial for engineers and water planners, who work on such sustainable systems to have a strong knowledge of the interaction between the water cycle’s components. The figure below illustrated different types of LID practices.
LID practices have been developed successfully in a variety of countries, particularly the UK, the US, Canada, and Australia. These countries follow a comprehensive process for implementing LID. The first step towards establishing the main concepts needed in order to install these techniques in Sudan is by carrying out investigative
research to assess the applicability of each technique taking into consideration the country’s climatic, architectural, and geological conditions. Precipitation quantities and soil conditions in Sudan will result in some techniques being more suitable than others.
However, designers need to carefully think through many factors to choose the most appropriate and effective technique(s) that will best meet the stormwater objectives. Among the factors are the presence of pollutants in runoff, the size of the catchment area, the hydrologic infiltration rate of the soil, and the presence of groundwater source. In addition, maintenance and cost should also be considered. For instance, it is better to implement a sustainable stormwater management system which requires materials that are already available in the local market. The commitment to sustainably control flood and employing LID techniques require the help of both, the public and the private institutions.
: ReliefWeb – Informing humanitarians worldwide. (2018). Sudan: Floods – Jul 2018. [online] Available at: https://reliefweb.int/disaster/fl-2018-000128-sdn [Accessed 7 Apr. 2019].