Changing properties of low flow of the Tarim River basin: Possible causes and implications

Deep understanding of low flow changes is of great practical and scientific merit in effective water resources management, particularly for Xinjiang, the typical arid region in China. Changes of the 7-day low flow (LF7) are analyzed based on long streamflow series at 5 hydrological using Mann-Kendall trend test and Sen's slope analysis. The results indicate that: (1) at the monthly scale, the LF7 peaks during June-August at the riverhead of the Tarim basin; at the annual scale, however, the LF7 peaked during 1962-2008. In the mainstream of the Tarim River, the LF7 peaks during July September and peaked during 1962-2008; (2) the LF7 was increasing before 1999 at the Kaqun station and this trend is significant statistically during 1991-1999. The LF7 at other hydrological stations showed decreasing trends from 1962 to the mid-1970s or early-1980s. Increased LF7 can be detected after change points, which should be attributed to increased temperature since the increased temperature can enhance melting processes; (3) the LF7 occurs during May June, which should be the result of increased irrigation demand and trapping effects of water reservoirs. The results of this study should be significant for regional water resource management under the influences of intensifying human activities and changing climate. (C) 2012 Elsevier Ltd and INQUA. All rights reserved.