Variation of hydrological regime with permafrost coverage over Lena Basin in Siberia
Variation of hydrological regime with permafrost coverage over Lena Basin in Siberia
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DOI：
10.1029/2008jd010537
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发表时间：
2009-04
影响因子：
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通讯作者：
B. Ye;Daqing Yang;Zhongliang Zhang;D. Kane
中科院分区：
文献类型：
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作者：
B. Ye;Daqing Yang;Zhongliang Zhang;D. Kane
[1]我们使用每月流量和永久冻土数据来研究西伯利亚勒拿河嵌套子流域的流量特征与流域永久冻土覆盖之间的关系。流域内的径流流态既有相似性，又有变异性。月最大/最小流量的比值直接反映了流量状况。该比率增加与流域面积从上游到下游的勒拿河流域内。这一格局不同于非多年冻土区，反映了多年冻土对区域水文情势的影响。该比值与流域多年冻土覆盖度呈显著正相关。这种关系表明，多年冻土条件并没有显着影响流量制度的低多年冻土（小于40%）地区，它强烈影响流量制度的地区多年冻土（大于60%）。各次盆地的温度和降水模式相似。流域降水与多年冻土条件关系不大，与河流流量状况有间接关系。冻结指数与多年冻土覆盖度之间存在着良好的相关性，表明寒冷的气候导致了多年冻土覆盖度的增加。这种关系将盆地热状况与多年冻土分布联系起来。温度与多年冻土范围，多年冻土范围与流量比之间的关系的组合链接温度，多年冻土，和流态在勒拿河流域。在阿尔丹次盆地，最大/最小流量比显着下降，在1942-1998年期间，由于基流的增加，这种变化是一致的，一般与西伯利亚东部多年冻土退化。
[1] We use monthly discharge and permafrost data to examine the relationship between discharge characteristics and basin permafrost coverage for the nested subbasins of the Lena River in Siberia. There are similarity and variation in streamflow regimes over the basin. The ratios of monthly maximum/minimum flows directly reflect discharge regimes. The ratios increase with drainage area from the headwaters to downstream within the Lena basin. This pattern is different from the nonpermafrost watersheds, and it clearly reflects permafrost effect on regional hydrological regime. There is a significant positive relationship between the ratio and basin permafrost coverage. This relationship indicates that permafrost condition does not significantly affect streamflow regime over the low permafrost (less than 40%) regions, and it strongly affects discharge regime for regions with high permafrost (greater than 60%). Temperature and precipitation have similar patterns among the subbasins. Basin precipitation has little association with permafrost conditions and an indirect relation with river flow regimes. There exists a good relation between the freezing index and permafrost extent over the basin, indicating that cold climate leads to high coverage of permafrost. This relation relates basin thermal condition with permafrost distribution. The combination of the relations between temperature versus permafrost extent, and permafrost extent versus flow ratio links temperature, permafrost, and flow regime over the Lena basin. Over the Aldan subbasin, the maximum/minimum discharge ratios significantly decrease during 1942–1998 due to increase in base flow; this change is consistent in general with permafrost degradation over eastern Siberia.