Recent stepwise sediment flux increase with climate change in the Tuotuo River in the central Tibetan Plateau

Substantial Increases in the Water and Sediment Fluxes in the Headwater Region of the Tibetan Plateau in Response to Global Warming

“…Both the water and sediment fluxes in the TTH displayed pronounced increases over the past few decades, with annual rates of increase of 0.025 ± 0.007 × km 3 /yr (3.5 ± 1.0%/yr, P < 0.001) and 0.03 ± 0.01 Mt/yr (5.9 ± 1.9%/yr, P < 0.001) from 1985 to 2016, respectively (Figure 2b). An abrupt change in both the runoff and sediment fluxes occurred in 1997, and this abrupt‐change year is consistent with the abrupt change in lake expansion on the TP and reflects a climate regime shift (Zhang et al, 2017; Zhang et al, 2020). The mean annual runoff increased by ~78% (from a rate of 0.72 ± 0.21 to 1.28 ± 0.55 km 3 /yr), and the mean annual sediment fluxes increased by ~135% (from a rate of 0.51 ± 0.28 to 1.20 ± 0.62 Mt/yr) over 1998–2016, relative to the baseline period (1985–1997).…”

“…However, changes in sediment fluxes on the TP remain poorly documented due to the scarcity of long‐term sediment monitoring and the complexity of the sediment source‐to‐sink processes (Lamoureux et al, 2014; Lane et al, 2017; Lu et al, 2010). A few recent studies have reported the stepwise changes in sediment fluxes on the TP and tried to link these changes to the El Niño event and climate change (Jiang et al, 2017; Zhang et al, 2020). For instance, Zhang et al (2020) found that the stepwise increase in the sediment fluxes mainly resulted from the enhanced erosive power and transport capacity despite the reduced sediment sources.…”

“…A few recent studies have reported the stepwise changes in sediment fluxes on the TP and tried to link these changes to the El Niño event and climate change (Jiang et al, 2017; Zhang et al, 2020). For instance, Zhang et al (2020) found that the stepwise increase in the sediment fluxes mainly resulted from the enhanced erosive power and transport capacity despite the reduced sediment sources. However, the specific sediment sources are not explicitly identified and the underlying processes of the increased sediment fluxes on the TP are largely uncertain.…”

“…The reliability and robustness of the long‐term daily observed data make such an approach more advantageous than the use of empirical or physical‐based models, which are commonly associated with inherent uncertainties (Huss & Hock, 2018; Lutz et al, 2014). In particular, the long‐term daily sediment data are extremely valuable in cold environments, as the current literature on sediment fluxes in cold environments mostly used monthly‐averaged data (Costa et al, 2018; Zhang et al, 2020) or less than 10 years of daily data (Beylich et al, 2017; Lamoureux et al, 2014). Our study fills this knowledge gap by examining the current long‐term daily hydroclimatic data to assess the effects of climate factors on riverine sediment fluxes in susceptible cold environments.…”

Summer precipitation characteristics on the southern Tibetan plateau

“…Mountains on the Tibetan Plateau (TP) are the headwaters of several major Asian rivers, supplying more than one‐quarter of the world's population, yet their hydrological processes remain poorly understood due to the extreme terrain, harsh climate and sparse observations (Yao et al, 2017; Immerzeel et al, 2020; Zhang et al, 2020). As an important source of streamflow, precipitation is one of the most critical inputs to glacio‐hydrological modelling of the “Water Towers” of the TP.…”