River discharge changes in the Qinghai-Tibet Plateau

Abstract

Annual mean discharge data of the five large rivers in the exorheic region of the Qinghai-Tibet Plateau from 1956 to 2000 are analyzed for trends with the Mann-Kendall nonparametric trend test. The results reveal that though in general no increasing trends exist in the total river discharges, significant regional differences of river discharge exist, reflecting the decreasing trends of discharge in the Yellow River and the Tongtian River (upper Changjiang River), an increasing trend in Yalong River, and inverted change in the Lancang River and Yarlung Zangbo River. Based on analyses of the seasonal discharge, it is found that climatic change had a significant effect on the seasonal variation of river discharge in the Qinghai-Tibet Plateau. In spring (from March to May) the discharge increased significantly, especially in the source area of the Yellow River. Together with the analyses on data of the mean temperature in the Northern Hemisphere and climatic data within the river basins, the relationship between discharges and mean temperature of the Northern Hemisphere is explored, which indicates that there is no increase in the stream discharge in the Qinghai-Tibet Plateau with global warming. It is probably the increasing evaporation, caused by rising temperature that offsets the hydrological effect of increasing precipitation.

The impacts of climate change and land cover/use transition on the hydrology in the upper Yellow River Basin, China

“…Cao et al (2006) found that TNH annual discharge exhibited a statistically non-significant decreasing trend between 1956 and 2000. Seasonally, except for increases detected for April, May, and June, all other months exhibited decreases in discharge.…”

“…A number of observational studies have shown that streamflow measured at TNH decreased over the past decades (Cao et al, 2006;Tang et al, 2008;Hu et al, 2011). Cao et al (2006) found that TNH annual discharge exhibited a statistically non-significant decreasing trend between 1956 and 2000.…”

Temperature and Precipitation Variability and Its Effects on Streamflow in the Upstream Regions of the Lancang–Mekong and Nu–Salween Rivers

“…Its rapid climate warming inevitably exerts profound effects on the global and regional hydrological cycle (Cao et al 2006;Immerzeel et al 2010;Lai 1996). Following climate warming, some parts of the Plateau witnessed increasing precipitation and streamflow (Gautam et al 2013).…”

“…Following climate warming, some parts of the Plateau witnessed increasing precipitation and streamflow (Gautam et al 2013). However, no significant annual precipitation trend as well as a statistically insignificant downward streamflow trend has generally prevailed in the upstream regions of some Chinese large rivers over the plateau since the mid-1960s (Cao et al 2006;Cuo et al 2014;Ding and Zhang 2008;Lai 1996;Qin et al 2010;Zhang et al 2011;Zhang et al 2012;Y.-Y. Zhang et al 2013).…”

Aeolian processes and their effect on sandy desertification of the Qinghai–Tibet Plateau: A wind tunnel experiment

“…Annual precipitation is >1000 mm in the southeastern area and decreases to <20 mm in the northeastern area, and the Plateau includes humid, semi-humid, semi-arid, and arid climates. In addition, as the "Third Pole" of the globe, the plateau is the source of the Yangtze and Yellow rivers and other water systems in southern Asia (Cao et al, 2006;Immerzeel et al, 2010). It is also one of the potential source areas for outbreaks of global dust storms .…”