Streamflow and its components in Ebinur basin: decoupling of
anthropogenic and climatic elements
Abstract
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. 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
c