2.1 Study area
The Yangtze River Basin (YRB) has a well-developed water system, with
four main tributaries: the Yalong River, the Minjiang River, the Jialing
River, and the Han River. This study was conducted in the middle and
lower reaches of the YRB with the area of 1.8*106km2, located from 90°33’ to 122°25’ E longitude and
24°30’ to 35°45’N latitude (see Figure 2 ) (Li et al., 2021).
[Insert Figure 2]
Figure 2 Study area and
location of 224 hydrometric stations
2.2 Data
The daily streamflow data of 267 hydrometric stations was downloaded
from the Annual Hydrological Report of the People’s Republic of China,
in which 224 hydrometric stations with 30 years records from 1970 to
1990 and from 2007 to 2016 were selected (see Figure 3 ).
According to the China Meteorological Data Network
(https://data.cma.cn/), daily precipitation, potential evaporation
and temperature data from 1961 to 2016 were downloaded from 698 evenly
distributed weather
stations.
The observed precipitation, potential evaporation and temperature data
were interpolated into the whole Yangtze River basin with the method of
Thiessen polygon (Meena et al., 2013). The interpolated precipitation,
potential evaporation and temperature data of the basin area
corresponding to 224 hydrometric stations were
averaged. From the geospatial
data cloud
(http://www.gscloud.cn/), the
30-meter digital elevation model (DEM) was downloaded. Data on 361
reservoirs located in the mid-lower reaches of the YZR were retrieved
from the Global Reservoir and Dam database (GRanD) (Lehner et al., 2011)
.
[Insert Figure 3]
Figure 3 Streamflow
record for 224 hydrologic stations. We here used complete decadal
streamflow data for year 1970–1990 and 2007-2016.