Water Accounting and Productivity Analysis to Improve Water Savings of Nile River Basin, East Africa: From Accountability to Sustainability
Hubert Hirwa,
Qiuying Zhang,
Fadong Li,
Yunfeng Qiao,
Simon Measho,
Fabien Muhirwa,
Ning Xu,
Chao Tian,
Hefa Cheng,
Gang Chen,
Hyacinthe Ngwijabagabo,
Benson Turyasingura,
Auguste Cesar Itangishaka
Affiliations
Hubert Hirwa
State Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
Qiuying Zhang
Chinese Research Academy of Environmental Sciences, Beijing 100012, China
Fadong Li
State Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
Yunfeng Qiao
State Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
Simon Measho
State Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
Fabien Muhirwa
University of Chinese Academy of Sciences, Beijing 100049, China
Ning Xu
State Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
Chao Tian
State Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
Hefa Cheng
Department of Environmental Science, Peking University, Beijing 100871, China
Gang Chen
Department of Civil & Environmental Engineering, College of Engineering, Florida A&M University-Florida State University, Tallahassee, FL 32310, USA
Hyacinthe Ngwijabagabo
College of Science and Technology, University of Rwanda, Kigali P.O. Box 3900, Rwanda
Benson Turyasingura
Department of Agriculture and Environmental Sciences, School of Agriculture, Haramaya University, Dire Dawa P.O. Box 138, Ethiopia
Auguste Cesar Itangishaka
University of Chinese Academy of Sciences, Beijing 100049, China
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.
