Mohamed A. Hamouda

Arid regions are prone to unprecedented extreme rainfall events that often result in severe flash floods. Using near-real-time precipitation data in hydrological modelling can aid in flood preparedness. This study analyzed rainfall data obtained from Integrated Multi-satellite Retrievals for Global Precipitation Measurement (IMERG V. 06) since 2001 to highlight recent trends of extreme rainfall indices for three selected watersheds in the UAE. Additionally, to validate the trends, the present study incorporated CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) into the analysis. Furthermore, for the first time, this study assessed the performance of the three products of IMERG in modelling flash flood events in the selected watersheds of UAE. A physical-based, fully distributed model was used to simulate the heaviest storm event. Also, a sensitivity analysis of the model’s output to variations in the input parameters was conducted using the one-factor-at-a-time method. The result of the trend analysis indicated that IMERG and CHIRPS show similar trends in both datasets, indicating agreement and reliability in their observations. However, there are a few instances where IMERG and CHIRPS show slight discrepancies in the nature of the trend. In general, the trend analysis results indicated an increasing trend of total precipitation (mm) and consecutive wet days, which suggests a rise in the risk of flash floods. The simulation of the flash flood event showed that the IMERG final product outperformed the other two products, closely matching the model output of the gauge rainfall data with mean absolute error (MAE) of 1.5, 2.37, and 0.5 for Wadi Ham, Wadi Taween, and Wadi Maidaq, respectively. The model’s performance was positively correlated with the size of the watershed. The sensitivity analysis results demonstrated that the model’s output was most sensitive to infiltration parameters. The study’s outcomes provide a good opportunity to improve near-real-time impact evaluation of flash flood events in the watersheds of the UAE.

Seawater desalination is emerging as one of the preferred systems for dealing with the problems of freshwater scarcity, which makes it necessary to redouble efforts to obtain an optimal and competent production process. For this reason, the coupling of water desalination and renewable energy systems is not surprising. This study applied a bibliometric analysis to evaluate the research trends on desalination systems and renewable energies from an engineering approach using optimizations or simulation techniques. The Scopus database was used for this study, selecting articles published between 2009 and 2022. A general analysis was carried out regarding trends in the number of articles produced, number of citations, subject area, journals, countries, institutes, and authors. Further, a more specific analysis was then performed in terms of renewable energy technologies used and preferred optimization/simulation methods and software used. The results also revealed that the field is growing, based on the number of articles published and the increase in citations. On the other hand, it was found that the most studied renewable energies, in coupling with desalination systems and from an optimization/simulation approach, are solar and wind.