Flood Hazard and Risk Area Identification: A Case of Gelana River Watershed, Southern Ethiopia
Wendafiraw Abdisa Gemmechis,
Daba Biru Leta,
Hindesa Danisa Bunda
Issue:
Volume 11, Issue 1, February 2023
Pages:
1-14
Received:
3 October 2022
Accepted:
26 December 2022
Published:
6 February 2023
Abstract: Floods are among the most devastating natural disasters in the world, claiming more lives and causing more damage to properties than any other natural phenomena. This study specifies flood hazard areas as well as flood risk areas of Gelana River Watershed. It specifically aims to investigate factors that create good conditions for flood hazard, generate flood hazard and risk areas from environmental and socio-economic factors using integration of Multi-Criteria Evaluation (MCE) and Geospatial Techniques. The research was conducted using quantitative research approach. Therefore, slope, elevation, soil type, land use land cover (LULC), and drainage density were the environmental factors developed for the generation of flood hazard. In addition, flood hazard, LULC and population data factors were developed to generate flood risk areas of Gelana river watershed. As the result, flood hazard map reveals 64.68, 1769.48, 1345.38, 244.37, 10.73 square kilometers of Gelana river watershed, is subjected to very high, high, moderate, low and very low flood hazardous respectively. It is revealed that 46.52% of the watershed has very high to high flood risk. The rest 47.20%, 6.24%, and 0.05% of the study area has medium, low and very low flood risk respectively. Therefore, the area incorporated under very high and high hazardous and risk areas are located around the Main River and lower course of the watershed.
Abstract: Floods are among the most devastating natural disasters in the world, claiming more lives and causing more damage to properties than any other natural phenomena. This study specifies flood hazard areas as well as flood risk areas of Gelana River Watershed. It specifically aims to investigate factors that create good conditions for flood hazard, gen...
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Geospatial Analysis of Flood Occurrences in Selected Sub Wards of Morogoro Municipality - Tanzania
Ernest William Mauya,
Denis Matilya
Issue:
Volume 11, Issue 1, February 2023
Pages:
15-23
Received:
27 February 2023
Accepted:
22 March 2023
Published:
31 March 2023
Abstract: Flood is characterized by an overflow of water than drainage capacity of what is normally a dry land. Urban flooding has become progressively recurring and deadly natural disaster across different cities in the world. Floods results to a lot of damages which vary from place to place. Therefore, in curbing flood and its effects, it is important to have information on flood occurrences at different geographical scales. In this study, geospatial tools have been used to analyze the flood occurrences of selected sub wards in Morogoro Municipality, between 2016 and 2021. It was found that 41.84% of all houses in the selected 56 sub wards assessed in Morogoro Municipality had experienced flooding within the 5 years. Some sub wards faced high flood occurrence as much as 91.8% of all houses in such sub wards: Gohalema were flooded while others like Mzigila sub ward received a minimal 5.26% flooding occurrence. To further describe the spatial distribution, maps of flooding occurrence, their distribution, intensity and ranges had been generated. Furthermore, flooding simulation of the study area at different elevations was conducted to see what areas would or would not be flooded. To conclude, the study had shown that there was flood occurrences in Morogoro municipality between 2016 and 2021, and further shown that, there was spatial relationship between flood Occurrence and elevation as well as drainage network. However, further studies on the factors that affect flood occurrences in the study area are recommended.
Abstract: Flood is characterized by an overflow of water than drainage capacity of what is normally a dry land. Urban flooding has become progressively recurring and deadly natural disaster across different cities in the world. Floods results to a lot of damages which vary from place to place. Therefore, in curbing flood and its effects, it is important to h...
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