Drought Assessment in Belt and Road Area Based on ERA5 Reanalyses

In general, the drought index is usually used for drought monitoring. It is necessary to distinguish different climates in large-scale drought studies because of different climates respond differently to drought. Based on ERA5 reanalysis datasets and the world Map of Koppen-Geiger Climate Classification, this paper evaluates the spatial and temporal distribution of drought under different climate areas along the Belt and Road (B&R) during 2000-2017 from four aspects: precipitation, runoff, evaporation and soil moisture. Results are as follows: except for parts of North Africa and West Asia, the annual variation of precipitation in the other places are not significant, but the runoff is the opposite. However, the amount of evaporation increased significantly in 2017, which may be caused by global warming or El Nino. Overall, the frequency of droughts may not increase in the near future, but if they do, they may occur faster and more dramatically.