Research on the climate changes and the simulation of the runoff over
the last 50 years, 1961-2010, in the Upper Tarim River basin of Southern
Xinjiang, China
Abstract
The upper Tarim River basin is supporting about 50 million people by
melting the glaciers and snow, which are highly vulnerable and sensitive
to climate change. Therefore, assessing the relative effects of climate
change on runoff of this region is essential not only for understanding
the mechanism of hydrological response over the mountainous areas in
Southern Xinjiang but also for local water resources management. This
study quantitatively investigated the climate change in the mountainous
area of the upper Tarim River basin, using the up-to-date ‘ground-truth’
precipitation and temperature data, the APHRODITE (1961–2010, 0.25°)
data; analyzed the potential connections between runoff data, observed
at Alar station, and the key climatological variables; and discussed the
regression models on simulating the runoff based on precipitation and
temperature data. The main findings of this study are: (1) both annual
precipitation and temperature generally increases at rates of 0.85
mm/year and 0.25 ℃/10a, respectively, while the runoff data measured at
Alar station shows fluctuating decreasing trends; (2) there are
significant spatial differences in the temporal trends of precipitation,
for example, the larger increasing rates of precipitation occurs in the
Karakoram Mountains, while the larger decreasing rates happens in
northwestern of Kashgar County; (3) the decreasing trends of temperature
mainly occurs in the Kashgar County and its surrounding areas in Summer;
(4) seasonal correlations in trends of precipitation and temperature are
more significant than those at monthly and annual scale; and (5) the
regression model in simulating the runoff in the upper Tarim River basin
based on Radial Basis Function (RBF) is better than that based on
least-squares method, with the predictive values based on RBF models
significantly better (Correlation coefficient, CC, ~
0.85) than those by least-squares models (CC ~ 0.75).
These findings will provide valuable information to inform environmental
scientists and planners on the climate change issues in the upper Tarim
River basin of Southern Xinjiang, China, under a semiarid-arid cl