Browsing by Author "Cheng, Hefa"

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    Water Accounting and Productivity Analysis to Improve Water Savings of Nile River Basin, East Africa: From Accountability to Sustainability
    (agronomy, 2022-03-28) Hirwa, Hubert; Zhang, Qiuying; Li, Fadong; Qiao, Yunfeng; Measho, Simon; Muhirwa, Fabien; Xu, Ning; Tian, Chao; Cheng, Hefa; Chen, Gang; Ngwijabagabo, Hyacinthe; Turyasingura, Benson; Itangishaka, Auguste Cesar
    Complete water accounting (WA) and crop water productivity (CWP) analysis is crucial for evaluating water use efficiency (WUE). This study aims to evaluate the contributions of hydro meteorological factors to the changes of WA and CWP and subsequent WUE based on the data from 2009–2020 in the Nile River Basin (NRB), East Africa (EA). The Mann-Kendall (MK) statistical test and Sen’s slope estimator were applied to detect the trends of climatic factors, and the AquaCrop model was used to simulate the crop yields in response to water balance and consumption based on crop physiological, soil water, and salt budget concepts. For the years 2012 and 2019, the mean of climatic water deficit P − ETa was 71.03 km3 and 37.03 km3 , respectively, which was expected to rise to ~494.57 km3 by 2050. The results indicated that the basin water budget was unbalanced due to the coupled impact of year-to-year hot and dry conditions and increase in water abstraction, an indication of water deficit or stress. CWP and WUE increased during the study period with different changing patterns. CWP was also found to correlate to the yield of major crops (p-value > 0.05). It was concluded that climatic factors influenced the crop yield, CWP, and WUE in the study area. Thus, the improvement of CWP and WUE should rely on advanced water-saving innovations. The findings of this study could help water managers to improve water productivity by focusing on water account potentials and creating regional advantages by deploying water in combination with surplus flow from upstream to downstream consumption.
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    Water Accounting and Productivity Analysis to Improve Water Savings of Nile River Basin, East Africa: From Accountability to Sustainability.
    (Kabale University, 2024) Hirwa, Hubert; Zhang, Qiuying; Li, Fadong; Qiao, Yunfeng; Measho, Simon; Muhirwa, Fabien; Xu, Ning; Tian, Chao; Cheng, Hefa; Chen, Gang; Ngwijabagabo, Hyacinthe
    Climate change impacts on drylands pose more vexing risks to socio-ecological systems, resulting in food security issues, biodiversity loss, and livelihood shifts in Africa. This study critically reviewed relevant literature to evaluate the complexities and feedback loops between the climate–drylands–food security (CDF) nexus, which helps assess tactics to attain sustainable dryland ecosystem management under the changing environment. Comprehensive CDF frameworks are explored for dryland dynamics, ecosystem services, and food security (FS), and current high-precision ecosystem observation networks are used to detect regional-level climate variability and identify hotspots. In addition, this review also examines challenges and uncertainties for CDF systems and effective agrarian innovations as a way forward. To bridge the gap from science to policy making in the CDF nexus, it is vital to enhance the impacts and feedback of ecohydrological processes on agrarian production, ecosystem service tradeoffs and their effects on livelihoods, and regional development and preservation by optimization of the ecological water security pattern. This state-of-the-art assessment uses acquired information and knowledge to conceptually evaluate the past, current, and future impacts and risks and facilitates decision-making through the delivery of long-term sustainability and socio-ecological resilience.