2 MATERIALS AND METHODS
2.1 Study area
The EIB is located in the core part of Eurasia (Figure 1), spanning an
area of 1.15 × 107 km2; it includes
16 closed inland basins and 23 sub-basins, which are shown in Figure 1
and Table 1. Notably, the AET simulation based on the hydrologic budget
method is targeted at closed inland basins. Glaciers are distributed
throughout the mountainous areas of the central and eastern basins,
being mainly located in the Qinghai-Tibetan Plateau. Due to the inland
location of the EIB, its climate is characterized by low precipitation
and high evaporation, and the mean annual precipitation and AET are
353.4 and 358.8 mm, respectively. The mean annual precipitation, AET,
and coefficient of variation for the monthly precipitation series in
each basin are shown in Table 1. There are nine closed basins in the EIB
with a mean annual precipitation <200 mm; these basins are
predominantly located in the eastern and southern regions. The highest
mean annual precipitation occurs in the CSB, exceeding 500 mm, while
lowest occurs in the TB, being <100 mm. The coefficient of
variation for monthly precipitation in the EIB is 0.20; it is highest in
the QPB (1.34) and lowest in the CSB (0.21).