Browsing by Author "Hamunyela, Eliakim"

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    Risks profile of natural hazards and selected diseases in Namibia
    (The Risk Profiling Project, 2024) Hipondoka, Martin; Hamunyela, Eliakim
    The occurrence and effects of natural disasters and infectious diseases in Namibia are diverse and vary in different areas, indicating the varying levels of exposure, sensitivity, and adaptability within the Namibian society. The diverse and pervasive occurrence of these disasters are costly to the country when dealt with in a non-holistic manner. Consequently, Namibia promulgated a disaster risk management law, the Disaster Risk Management Act 10 of 2012, to provide a legal framework for managing disaster risks in the country. This legal instrument provided the necessary framework for facilitating the nation’s transition from disaster management to risk management and focus on resilience-building, which aligns with the Sendai Framework for Disaster Risk Reduction 2015–2030. However, a comprehensive understanding of disaster risk for various hazards in the country was lacking. The Government of the Republic of Namibia, through the Office of the Prime Minister, commissioned this study to profile the disaster risks of pertinent natural hazards and selected diseases countrywide at the level of Population Enumeration Area, the lowest possible spatial scale in the country. The study profiled the vulnerability and risk of nine natural hazards (drought, flood, heatwave, wildfire, sea level rise, frost, earthquakes, windstorms and lightning) and five diseases (malaria, HIV/AIDS, COVID-19, foot and mouth disease and diarrhoea). As the profile shows, there is not a single place in Namibia which is risk-free from all 14 hazards analysed in this profile. There are, however, areas that are free from some risks such as malaria, wildfire, foot and mouth disease, and sea level rise. At the same time, there is not a single place in Namibia which is at high risk of all 14 hazards. The profiled risks are spatially differentiated. Nevertheless, there are areas with high or very high risk levels for multiple disaster risks. In the Zambezi Region, for example, there are areas compounded with a high or very high risk of floods, malaria, diarrhoea, and foot and mouth disease. The south eastern part of the //Kharas Region is concurrently under high or very high risk of heatwaves, frost and earthquakes. This speaks to the need for resilience building efforts to be risk-holistic and area-specific, to reduce vulnerability and disaster risk of the communities and infrastructure. Thus, this profile has established the baseline information necessary for Namibia to move from managing natural disasters and leverage the mechanism for disaster risk reduction in accordance with the Sendai Framework. However, there is a need to integrate disaster risk maps in the planning processes at all levels of government and across all sectors to reduce the impacts of natural hazards on society. For this integration to be effective, it is imperative to develop an integrated and spatially-enabled data management system for storing data on hazards, risks, vulnerabilities, impacts and interventions to support resilience-building efforts. This data management system should be accompanied by mandatory and standardised annual reporting of all hazards and their impacts to ensure that resilience-building efforts are evidence-based
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    Spatio-temporal characterization of surface water dynamics with Landsat in endorheic Cuvelai-Etosha Basin (1990–2021)
    (Elsevier, 2022) Hamunyela, Eliakim; Hipondoka, Martin; Persendt, Frans; Nghiyalwa, Hilma Sevalia; Thomas, Chris; Matengu, Kenneth
    Socio-economic damages caused by extreme floods have been increasing rapidly in recent years, mainly driven by changes in the climate and modulated by increasing human population in deltic areas and floodplains. The Cuvelai-Etosha Basin (CEB) in southern Africa, covering southern Angola and northern Namibia, experiences socially and economically devastating extreme floods. Yet, accurate information on past and current surface water changes and dynamics is lacking. Here, we estimate and map the surface water extents in the CEB and its surroundings (CEB + S) for 32 years (1990–2021) from Landsat data using random forest models to provide long-term baseline information on surface water changes and dynamics. Based on the reference data, a total of 15,677 ± 1080 km2 have been inundated by surface water in the CEB + S during 1990–2021. This extent was accurately mapped by our local water extent product (mapped area = 16,273 km2, user’s accuracy = 91.5 ± 2.5%, producer’s accuracy = 91.1 ± 6%). With user’s and producer’s accuracy of 91%, our overall water extent provides the first most accurate long-term baseline information on surface water inundation in CEB + S necessary for local spatial planning processes to minimise future negative impacts of floods in the basin. Interannual variability of surface water extent is, however, high, with water extent ranging from 520.8 ± 375.7 km2 to 12372.3 ± 1154.7 km2 during the 1990–2021 period. The largest annual water extents (>10,000 km2) were recorded in 2006, 2008, 2009, 2011, and 2017, whereas the smallest extents (<1000 km2) were recorded in 1992 and 2019. We found that over 40% of the area inundated in the CEB + S during 1990–2021 was inundated less than 9 times. With human population increasing rapidly in the CEB + S, rarely inundated areas with short water residence could become a prime target for human settlements, which may lead to huge socio-economic damages during extreme floods if no preventive measures are put in place. Globally available surface water maps from the Global Land Analysis and Discovery (GLAD) and European Commission’s Joint Research Centre (JRC) did not provide realistic surface water extent for CEB + S, especially during years with extreme floods. Therefore, locally adopted product for operational monitoring of surface water in the CEB + S is needed to provide accurate information for informing spatial planning processes and surface water resource management strategies in this endorheic basin and help minimise future negative impacts of floods.