Variability and stability of water resource in the arid regions of China: a case study of the Tarim River basin

Abstract

In this study, we analyzed two long term streamflow records of the Aksu River basin, the main water source of the Tarim River basin, using multiscale t-test and F-test with the aim to understand the changing characteristics of hydrological regimes in terms of the first moment (mean or average) and the second moment (variance). The results indicate the following: 1) In general, increasing streamflow was observed in two periods: 1965―1970 and 1980―1985. Since 1986, the streamflow of the Aksu River has been persistently increasing. 2) Synchronous variations can be found between the subseries variance and the subseries mean, i.e., an increase in the subseries mean is usually consistent with an increase in the subseries variance, and vice versa. Therefore, streamflow changes of the Aksu River tend to be unsteady, although streamflow is persistently increasing since 1986. 3) The streamflow changes of the Aksu River are heavily dependent on precipitation and ice melting. Increase of precipitation and more ice melting in recent decades, particularly after the 1980s, are the major causes of streamflow changes of the Aksu River basin.

Keywords

multiscale variations / streamflow variations / scanning t-test / scanning F-test / Aksu River / Tarim River basin