Differences in the water-balance components of four lakes in the southern-central Tibetan Plateau
The contrasting patterns of lake-level fluctuations across the Tibetan Plateau (TP) are indicators of differences in the water balance over the TP. However, little is known about the key hydrological factors controlling this variability. The purpose of this study is to contribute to a more quantitat...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-01-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | http://www.hydrol-earth-syst-sci.net/20/209/2016/hess-20-209-2016.pdf |
| Summary: | The contrasting patterns of lake-level fluctuations across the Tibetan
Plateau (TP) are indicators of differences in the water balance over the TP.
However, little is known about the key hydrological factors controlling this
variability. The purpose of this study is to contribute to a more
quantitative understanding of these factors for four selected lakes in the
southern-central part of the TP: Nam Co and Tangra Yumco (increasing water
levels), and Mapam Yumco and Paiku Co (stable or slightly decreasing water
levels). We present the results of an integrated approach combining
hydrological modeling, atmospheric-model output and remote-sensing data. The
J2000g hydrological model was adapted and extended according to the specific
characteristics of closed-lake basins on the TP and driven with High Asia
Refined analysis (HAR) data at 10 km resolution for the period 2001–2010.
Differences in the mean annual water balances among the four basins are
primarily related to higher precipitation totals and attributed runoff
generation in the Nam Co and Tangra Yumco basins. Precipitation and
associated runoff are the main driving forces for inter-annual lake
variations. The glacier-meltwater contribution to the total basin runoff
volume (between 14 and 30 % averaged over the 10-year period) plays a
less important role compared to runoff generation from rainfall and snowmelt
in non-glacierized land areas. Nevertheless, using a hypothetical ice-free
scenario in the hydrological model, we indicate that ice-melt water
constitutes an important water-supply component for Mapam Yumco and Paiku Co,
in order to maintain a state close to equilibrium, whereas the water balance
in the Nam Co and Tangra Yumco basins remains positive under ice-free
conditions. These results highlight the benefits of linking hydrological
modeling with atmospheric-model output and satellite-derived data, and the
presented approach can be readily transferred to other data-scarce closed
lake basins, opening new directions of research. Future work should go
towards a better assessment of the model-chain uncertainties, especially in
this region where observation data are scarce. |
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| ISSN: | 1027-5606 1607-7938 |