Virtual water transfers in Africa: Assessing topical condition of water scarcity, water savings, and policy implications

• Published in: The Science of the total environment 2022-08, Vol.835, p.155343-155343, Article 155343
• Main Authors: Hirwa, Hubert, Peng, Yu, Zhang, Qiuying, Qiao, Yunfeng, Leng, Peifang, Tian, Chao, Yang, Guang, Muhirwa, Fabien, Diop, Salif, Kayiranga, Alphonse, Li, Fadong, Chen, Gang
• Format: Article
• Language: English
• Subjects: Africa; Virtual water flows; Water dependency; Water resource management; Water saving; Water scarcity
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2022.155343

Africa is facing an increasing challenge with respect to water scarcity (WS), which is driven by climate change, population growth, and socioeconomic growth combined with inadequate water resources management. In particular, there is significant concern of virtual water (VW) trade, which plays the key role in water resource management and food security sustainability. Using bilateral trade data, this study consistently evaluated the change and balanced trade of major grains, the VW flows, WS status, water dependency (WD), water self-sufficiency (WSS), and water savings/losses within5 African sub-regions and their partners from 2000 to 2020. The ratio of water use to water availability was used to estimate the WS. The WD was quantified by the ratio of the net VW import to the regional water appropriation and the regional water savings/losses were also quantified by multiplying the inter-regional trade by the virtual water content of the imported/exported grains. The overall average trade deficit of African regions was found to increase to −1364.22 × 106 tons and Africa imported 41,359.07 Bm3 of VW from grain products. Green water contributed 79.33% of the total VWI. The WS values for East African countries were >100, indicating overexploitation. Besides, the overall WD in Africa was 465.5% for the studied period. The trade of main grains between Africa and the rest of the planet corresponded to a global water loss of 2820.7 Bm3·yr−1. However, the inter-continental cereal VW trade pattern and high trend will continue in the future. In view of the rising tension of WS, some African countries need to revise international crop trade and water resources conservation policies to promote a more balanced ecosystem. This study exemplifies that decision makers would consider VW flows and water savings/losses for enhancing water use efficiency and fair trading, thus increasing food production in Africa. [Display omitted] •Virtual water trade of grains, water scarcity, and water savings from 2000 to 2020 were assessed.•In Africa, green water made up the largest portion of the total virtual water import.•Global water loss through the trade of major grains in Africa increased from 2000 to 2020.•Future policy implications for sustainable water resources management are proposed.