Siabi Ebenezer K, Adu-Poku Akwasi, Otchere Nathaniel Oppong, Awafo Edward A, Kabo-Bah Amos T, Derkyi Nana S A, Akpoti Komlavi, Anornu Geophrey K, Adjei Eunice Akyereko, Kemausuor Francis, Yazdanie Mashael
Earth Observation Research and Innovation Center (EORIC), University of Energy and Natural Resources, P.O. Box 214, Sunyani, Ghana.
Regional Center for Energy and Environmental Sustainability, University of Energy and Natural Resources, P. O. Box 214, Sunyani, Ghana.
Discov Water. 2024;4(1):76. doi: 10.1007/s43832-024-00140-7. Epub 2024 Oct 7.
This study evaluates flood susceptibility and risk on Bulk Supply Points in the Greater Accra region (GAR) using a Frequency Ratio model based on 15 flood conditioning factors. The model explores the influence of natural, meteorological and anthropogenic factors on flooding occurrences under the Shared Socioeconomic Pathway (SSP) scenarios and assesses flood risks at Bulk Supply Points (BSPs). Flood susceptibility mapping was conducted for both current and future periods under various SSP scenarios. Results reveal that elevation, slope, soil type, distance from urban areas, and SPI are the most influential factors contributing to flooding susceptibility in the region. The current flood map, about 37% of the total area of GAR categorized under the moderate flood-susceptible zone category followed by about 30% categorized under the low flood-vulnerable zone. However, about 16% was categorized under the very high flood-vulnerable zone. The study projects increasing flood susceptibility under the SSP scenarios with intensification under SSP2 and SSP3 scenarios. For instance, the areas categorized as high and very high flood susceptibility zones are projected to expand to approximately 32% and 26% each by 2055 under SSP3. The study also assesses flood risks at Bulk Supply Points (BSPs), highlighting the escalating susceptibility of power assets to flooding under different scenarios. For instance, in the very high scenario, flooding is estimated to reach 640 h in 2045 and exceed 800 h in 2055-more than double the 2020 baseline. The analysis shows the bulk supply points face increasing flood susceptibility, with risks escalating most sharply under the severe climate change SSP3 and SSP5 scenarios. Over 75% of BSPs are expected to fall in the low- to medium-risk categories across SSPs while more than 50% of BSPs are within medium- to high-risk categories in all scenarios except SSP1, reflecting the impact of climate change. SSP3 and SSP5 stand out with over 60% of BSPs facing high or very high flooding risks by 2055. It indicates moderate resilience with proper adaptation but highlights potential disruptions in critical infrastructure, such as BSPs, during persistent flooding. The findings of the study are expected to inform Ghana's contributions towards addressing Sustainable Development Goals (SDGs) 7, 11 and 13 in Ghana.
本研究使用基于15个洪水条件因素的频率比模型，评估大阿克拉地区（GAR）的大量供水点的洪水易发性和风险。该模型探讨了自然、气象和人为因素在共享社会经济路径（SSP）情景下对洪水发生的影响，并评估了大量供水点（BSPs）的洪水风险。在各种SSP情景下，对当前和未来时期都进行了洪水易发性制图。结果表明，海拔、坡度、土壤类型、距市区距离和标准化降水指数（SPI）是该地区洪水易发性的最具影响力的因素。当前的洪水地图显示，大阿克拉地区总面积中约37%被归类为中度洪水易受影响区，其次约30%被归类为低洪水脆弱区。然而，约16%被归类为极高洪水脆弱区。该研究预测，在SSP情景下洪水易发性将增加，在SSP2和SSP3情景下会加剧。例如，到2055年，在SSP3情景下，被归类为高和极高洪水易受影响区的面积预计将分别扩大到约32%和26%。该研究还评估了大量供水点（BSPs）的洪水风险，突出了不同情景下电力资产对洪水的易感性不断升级。例如，在极高情景下，预计2045年洪水持续时间将达到640小时，2055年超过800小时，是2020年基线的两倍多。分析表明，大量供水点面临的洪水易发性不断增加，在严重气候变化的SSP3和SSP5情景下风险上升最为急剧。预计超过75%的大量供水点在所有SSP情景下将属于低至中等风险类别，而除SSP1外，在所有情景下超过50%的大量供水点属于中至高风险类别，这反映了气候变化的影响。到2055年，SSP3和SSP5情景尤为突出，超过60%的大量供水点面临高或极高的洪水风险。这表明通过适当的适应措施具有一定的恢复力，但也突出了在持续洪水期间关键基础设施（如大量供水点）可能受到的干扰。该研究的结果预计将为加纳在实现加纳的可持续发展目标（SDGs）7、11和13方面的贡献提供参考。
