Streamflow and its components in Ebinur basin: decoupling of anthropogenic and climatic elements
Detecting and assessing changes in the hydrological cycle and how it
responds to a changing environment is essential for maintaining regional
ecological security and restoring damaged ecosystems. The Ebinur Lake
basin, an important ecological barrier in the Junggar Basin of Xinjiang,
China, has undergone significant changes in recent decades as a result
of massive eco-rehabilitation projects and increased anthropogenic
factors. Former studies concentrated on the effect of environmental
changes on total runoff, while studies on runoff components in arid
region were absent. To solve the above defects, we separated the study
period into three phases based on the heuristic segmentation
algorithm：the reference phase (1964-1985) and two impact phases: I
(1986-2000) and II (2001-2017). The Variable Infiltration Capacity (VIC)
surface models were used to determine the contribution of both human
activities and climate change to streamflow along with its components.
Based on the VIC model of streamflow splitting, the results showed that
surface runoff, baseflow and snowmelt accounted for 20.97%, 60.37% and
23.42% of the annual runoff volume respectively. The differential
evolution Markov chain (DEMC) algorithm improved the Nash-Sutcliffe
efficiency by 20% over the traditional SCE-UA algorithm, which exceeded
0.6 and reached reliable level. Increases in cropland and forested land
were partially contributed by grassland and heathland throughout the
study period, While the leaf area index (LAI) of the season of plant
growth showed a trend of 0.002 increase per year. Direct human activity
was the main factor in the reduction of runoff in impact phase I and
indirect human activity in impact phase II, Whereas, in the total impact
phase, climate change was the main driver of runoff increase. Our
results provide insight into decision making related to water stress in
changing circumstances in arid regions.
作者:
Wang Yinghui,Han Lijie,Liu Jie,Ding Jianli,Bao Qingling
DOI:10.22541/au.162039797.73205694/v1
