The Awash river basin has been the most extensively developed and used river basin in Ethiopia since modern agriculture was introduced. This paper investigated the annual precipitation, temperature, and river discharge variability using the innovative trend analysis method (ITAM), Mann–Kendall (MK) test, and Sen’s slope estimator test. The results showed that the trend of annual precipitation was significantly increasing in Fitche (Z = 0.82) and Gewane (Z = 0.80), whereas the trend in Bui (Z = 69) was slightly decreasing and the trend in Sekoru (Z = 0.45) was sharply decreasing. As far as temperature trends were concerned, a statistically significant increasing trend was observed in Fitche (Z = 3.77), Bui (Z = 4.84), and Gewane (Z = 5.59). However, the trend in Sekoru (Z = 1.37) was decreasing with statistical significance. The discharge in the study basin showed a decreasing trend during the study period. Generally, the increasing and decreasing levels of precipitation, temperature, and discharge across the stations in this study indicate the change in trends. The results of this study could help researchers, policymakers, and water resources managers to understand the variability of precipitation, temperature, and river discharge over the study basin.

This study investigated the annual and seasonal rainfall variability at five selected stations of Amhara Regional State, by using the innovative trend analysis method (ITAM), Mann-Kendall (MK) and Sen’s slope estimator test. The result showed that the trend of annual rainfall was increasing in Gondar (Z = 1.69), Motta (Z = 0.93), and Bahir Dar (Z = 0.07) stations. However, the trends in Dangla (Z = −0.37) and Adet (Z = −0.32) stations showed a decreasing trend. As far as monthly and seasonal variability of rainfall are concerned, all the stations exhibited sensitivity of change. The trend of rainfall in May, June, July, August, and September was increasing. However, the trend on the rest of other months showed a decreasing trend. The increase in rainfall during Kiremt season, along with the decrease in number of rainy days, leads to an increase of extreme rainfall events over the region during 1980–2016. The consistency in rainfall trends over the study region confirms the robustness of the change in trends. Innovative trend analysis method is very crucial method for detecting the trends in rainfall time series data due to its potential to present the results in graphical format as well. The findings of this paper could help researchers to understand the annual and seasonal variability of rainfall over the study region and become a foundation for further studies.

Several catalyst materials composed of tin oxide composites (SnOx) with a novel coralline structure are synthesized by using a facile hydrothermal self‐assembly process. The catalysts are then used to prepare a SnOx/GDL (gas diffusion layer) electrode for CO2 electroreduction to formate in 0.5 m KHCO3 aqueous solution. Influential factors, such as hydrothermal synthesis temperature (T)/time (Δt) and the valence state of Sn in the SnOx nanocatalysts, on both catalysts’ morphologies, and Faradaic efficiency for formate production are investigated systematically. By using a SnOx(100–8)/GDL electrode (i.e. T and Δt are 100 °C and 8 h, respectively) as the cathode, the high maximum faradaic efficiency of 87.1 % is achieved at a controlled potential of −1.6 V, which is superior to all the reported SnOx and Sn/SnOx catalysts in the literature. By combining X‐ray photoelectron spectroscopy and X‐ray diffraction analysis, the coralline‐structured SnOx is observed to be composed of SnO and SnO2, where the SnO is covered by a SnO2 film about 1–2 nm thick, which makes a contribution to the catalytically active sites for CO2 electroreduction. This coralline‐structured SnOx exhibits high durability, as evaluated by a stable catalytic current density of approximately 10 mA cm−2 over 20 h of continuous operation. This work highlights the controlling role of the correct morphology and the valence state of tin oxide on formate formation during CO2 reduction in aqueous solution.

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As basic data, the river networks and water resources zones (WRZ) are critical for planning, utilization, development, conservation and management of water resources. Currently, the river network and WRZ of world are most obtained based on digital elevation model data automatically, which are not accuracy enough, especially in plains. In addition, the WRZ code is inconsistent with the river network, hindering the efficiency of data in hydrology and water resources research. Based on the global 90-meter DEM data combined with a large number of auxiliary data, this paper proposed a series of methods for generating river network and water resources zones, and then obtained high-precision global river network and corresponding WRZs at level 1 to 4. The dataset provides generated rivers with high prevision and more accurate position, reasonable basin boundaries especially in inland and plain area, also the first set of global WRZ at level 1 to 4 with unified code. It can provide an important basis and support for reasonable use of water resources and sustainable social development in the world.