VULNERABILITY ASSESSMENT OF AREAS ALONG MULUNGUZI RIVER TO POTENTIAL DAM FAILURE FLOODS, ZOMBA CITY

The study aimed at assessing the vulnerability of areas along the Mulunguzi river to potential floods influenced by dam failure. Provention Consortium (2007) defined vulnerability as the potential to suffer harm or loss, related to the capacity to anticipate a hazard, cope with it, resist it and recover from its impact. Both vulnerability and its antithesis, resilience, are determined by physical, environmental, social, economic, political, cultural, and institutional factors. The study is centred on the warning which was issued by the Department of Disaster Risk Management Affairs on the potential failure of the Chagwa Dam on Zomba Plateau. The failure of the dam could result in inundating areas along the Mulunguzi river. Therefore, recognizing that vulnerability differs among individuals and communities, the study focused on assessing the levels of vulnerability in prone areas and not excluding their causes. Furthermore, identifying elements at risk and their susceptibility to adverse impacts of the hazard based on exposure.
It was identified that among the areas along Mulunguzi river, Matawale is more vulnerable due to various underlying causes of vulnerability for instance peoples’ livelihood, nature of houses constructed, land use, and so forth. Whereas Mangasanja is less vulnerable to DFF floods. Various elements at risk were determined and later classified e.g. roads, people, buildings, environment, and many more.
The study was conducted by field visits, desk study, and flood vulnerability mapping. A field visit was after identifying elements at risk and ground-truthing. Desk study involves various statistical operations to determine the level of socio-economic and physical vulnerability. Whilst mapping was done to determine and exhibition the level of vulnerability in all prone areas and to show levels of susceptibility to adverse impacts based on proximity to the river.

Provention Consortium (2007) defined vulnerability as the potential to suffer harm or loss, related to the capacity to anticipate a hazard, cope with it, resist it and recover from its impact. The study is centred on the warning which was issued by the Department of Disaster Risk Management Affairs on the potential failure of the Chagwa Dam on Zomba Plateau. It was identified that among the areas along Mulunguzi river, Matawale is more vulnerable due to various underlying causes of vulnerability for instance peoples’ livelihood, nature of houses constructed, land use, and so forth. Whilst mapping was done to determine and exhibition the level of vulnerability in all prone areas and to show levels of susceptibility to adverse impacts based on proximity to the river.

Zomba is located in the southern region of Malawi. Its coordinates are 15.3766°S and 35.3357°E (Brinkhoff, 2019). Zomba has a wonderful plateau, On this plateau is where the dam system was constructed in 2001 although the whole project started in 1997 (World Bank, 2013). Chagwa dam is located in Zomba next to Mulunguzi dam and it has 0.43Kilometres length. However, the Mulunguzi dam is the main dam that supplies water to most of the areas in Zomba city. Chagwa dam is mainly made of mud and has been in existence for many, many years. The surrounding area has been logged and this amongst other things, has led the soils to be degraded and erosion to occur. With the recent heavy rains, the dam has suffered further degradation (Zomba Forest Lodge, 2019). Unfortunately, the dam is at risk for failure which could result in devastating floods in the Mulunguzi river affecting areas along the river. Zomba has a population of 851,737 people and 105,013 staying in the city. (National Statistical Office, 2018). The district is 923m above sea level and receives about 906mm of annual rainfall (Climate-Data.org, 2021). The study was done in four residential areas along Mulunguzi river which are located in Zomba municipality, namely; Old Naisi, Matawale, Mangasanja, and Mulunguzi Secondary School.

Traditional authority: TA Malemia

District: Zomba

Coordinates: -15.28605, 35.3424