Quantifying the contribution of glacier meltwater in the expansion of the largest lake in Tibet
Quantifying the contribution of glacier meltwater in the expansion of the largest lake in Tibet
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DOI：
10.1002/2016jd025424
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发表时间：
2016-10
期刊：
影响因子：
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通讯作者：
K. Tong;F. Su;Baiqing Xu
中科院分区：
文献类型：
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作者：
K. Tong;F. Su;Baiqing Xu
四棱错湖是目前西藏最大的内陆湖，自20世纪70年代以来，湖面面积扩大了约40%，1999年后明显加速。将变入渗能力（维克）陆面水文模型与度日冰川融化模型相结合，建立了四棱错流域水文模型框架，旨在量化各径流分量对湖泊蓄水量变化的贡献。我们发现，在1979-2013年期间，冰川融化对湖泊总水量的贡献不到10%，而非冰川化地区的降水径流约占67- 75%。与1979-1999年相比，2000-2013年向湖泊输入的年平均水量增加了2.15 × 109 m3 yr−1。湖面上的降水量、降水径流量和冰川融水径流量分别占总增加量的13%、82%和5%，这表明21世纪初的大幅度扩张主要是由于降水径流量的增加。当模拟1979-2013年期间的湖平面变化时，我们发现，当冰川融化时，水位上升了14.1米，而当冰川融化时，水位仅上升了10.5米，下降了约四分之一。研究表明，尽管冰川融水对整个四灵错湖的水量贡献不足10%，但对四灵错湖的水位控制起着重要作用。
Lake Siling Co is currently the largest endorheic lake in Tibet, and the lake surface area has expanded by about 40% since the 1970s, with a remarkable acceleration after 1999. In this study, a hydrologic modeling framework was established by linking the Variable Infiltration Capacity (VIC) land surface hydrologic model with the degree‐day glacier‐melt model over the Lake Siling Co basin, with an aim to quantify the contribution of each runoff component to changes in the lake storage. We found that glacier melt contributed to less than 10% of the total water input to the lake during 1979–2013, while precipitation‐induced runoff in nonglacierized area was responsible for about 67–75%. The mean annual water input to the lake increased by 2.15 × 109 m3 yr−1 in 2000–2013 relative to that in 1979–1999. The amount of precipitation over the lake surface, precipitation‐induced runoff, and glacier‐melt runoff accounted for 13%, 82%, and 5% of this total increase, respectively, suggesting that the substantial expansion of Siling Co in the 2000s was mostly due to the increase in precipitation‐induced runoff. When modeling lake level changes during 1979–2013, we found that the water level rose by 14.1 m when glacier melt was included and by only 10.5 m, a reduction of about one fourth, when glacier melt was removed. It is concluded that glacier melt played an important role in controlling the water level of Siling Co, although it only contributed less than 10% of water input to the lake during 1979–2013.