Discharge regime and simulation for the upstream of major rivers over Tibetan Plateau

Abstract

[1] The hydrological regimes for the major river basins in the Tibetan Plateau (TP), including the source regions of the Yellow (UYE), Yangtze (UYA), Mekong (UM), Salween (US), Brahmaputra (UB), and Indus (UI) rivers, were investigated through a land surface model and regression analyses between climate variables and runoff data. A hydrologic modeling framework was established across the TP to link the Variable Infiltration Capacity (VIC) land surface hydrology model with a degree-day glacier-melt scheme (VIC-glacier model) at a 1/12°Â 1/12°. The model performance was evaluated over the upper basins of the six rivers. The heterogeneity and scarcity of the meteorological stations are the major limitation for hydrological modeling over the TP. The relative contributions to streamflow from rainfall, snowmelt, and glacier melt for the six basins were quantified via the model framework and simulation. The results suggest that monsoon precipitation has a dominant role in sustaining seasonal streamflow over southeastern regions, contributing 65-78% of annual runoff among the UYE, UYA, UM, US, and UB basins. For the UI, the runoff regime is largely controlled by the glacier melt and snow cover in spring and summer. The contribution of glacier runoff is minor for the UYE and UM (less than 2% of total annual flow), and moderate for the UYA and US basins (5-7% of yearly flow), while glacier melt makes up about 12% and 48% of annual flow for the UB and UI basins, respectively.Citation: Zhang, L., F. Su, D. Yang, Z. Hao, and K. Tong (2013), Discharge regime and simulation for the upstream of major rivers over Tibetan Plateau,

Evaluating the streamflow simulation capability of PERSIANN-CDR daily rainfall products in two river basins on the Tibetan Plateau

“…Lack of rainfall gauge stations has brought a great challenge to hydrological and climate studies over the Tibetan Plateau (e.g., Yao et al, 2012;Zhang et al, 2013). Based on the demonstration in this study that PERSIANN-CDR is able to produce reasonably good streamflow in the UYZR and UYLR as compared to observed streamflow, we can speculate that the PERSIANN-CDR rainfall product has the potential to be a useful dataset and an alternative for the sparse gauge network in climate change and hydrological studies on the Tibetan Plateau considering the needs for long-term (more than 33 years) and high-resolution records.…”

Potential application of hydrological ensemble prediction in forecasting flood and its components over the Yarlung Zangbo River Basin, China

“…For Zone 1 and Zone 2, the overestimation is exacerbated by interpolating with gauges at which more snow and glacier exist. To relieve this problem, there are generally two ways to considering glacier-melt separately: energy balance 10 models to calculate melt as residual in the heat balance equation, and temperature-index models to quantify an empirical relationship between air temperature and melt rate (Zhang et al, 2013). Some studies have successfully coupled VIC with these two kinds of glacier-melt models.…”

“…Some studies have successfully coupled VIC with these two kinds of glacier-melt models. Zhang et al (2013) and Su et al (2016) embodied a simple degree-day glacier algorithm into VIC, and Zhao et al (2013) coupled an energy balance-based glacier model with VIC, showing acceptable performance with efficiency coefficient greater than 0.8 for the complete simulation period. However, one thing we should 15 bear in mind is that with the limited observed data in this special area, it is difficult to accurately separate the snow from glacier.…”

Rationalization of Altitudinal Precipitation Profiles in a Data-Scarce Glacierized Watershed Simulation in the Karakoram

“…In general, land surface hydrology model simulations are highly sensitive to the accuracy of the precipitation input. Reliable precipitation inputs are necessary for producing reasonable model parameters and simulations [64]. Therefore, the PLAPS has a significant impact on the outputs of the glacio-hydrological model used [9].…”

“…The Indus River basin, a large river originating from the southern slope of Karakoram, has cold climates and substantial precipitation during the boreal winter [5]. The precipitation pattern in the Upper Indus River is characterized by a peak in the winter months (approximately 37% of the annual total) and a peak in the summer months (44% of the annual total) [64], with the largest peaks occurring in the months of March and April [72]. Thus, ablation occurs during summer, and most accumulation occurs during the winter months on the southern slope of the Karakoram [5].…”