Degradation of frozen ground in Hailaer River basin and its impact on hydrologic processes
Degradation of frozen ground in Hailaer River basin and its impact on hydrologic processes
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海拉尔河流域冻土退化及其对水文过程的影响
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Li, Chong
中科院分区：
文献类型：
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作者：
Lu, Yinhao;Ye, Baisheng;Li, Chong
多年冻土退化对径流变化的影响已成为气候变化背景下研究的热点问题，但现有的研究主要集中在冻土退化与径流变化的关系上，本文通过对多年冻土退化与径流变化关系的研究，本文利用满洲里气象站的多年冻土深度资料，分析了近30年来冻土退化与径流的关系及其变化规律，结果表明，海拉尔河、坝后、红花尔基3个水文站冬季径流量增加了13%~ 20%，第四个断面（牙克石）的流量变化不明显，2 ~ 11月流量比（Q2/Q11）明显增加，而满洲里站同期最大冻结深度减少了约50 cm，这表明气候变暖条件下霜冻退化的影响是导致冬季消退曲线减缓的主要原因。从以下三个方面可以解释这种退化：首先，冻土的退化将导致含水层厚度、地表水入渗量和地下水储量的增加，从而增加冬季径流量;其次，地下水的循环比地表水慢得多，地下水库的扩大将导致河流径流衰退的时间更长;第三，霜冻退化对气候变暖的响应是一个缓慢的过程，其对径流变率的影响也是一个渐进的过程。
The effect of frost degradation on runoff variability in cold regions has become a hot issue under a changing climate.However,most existing researches on the subject have focused on exploring the relationship between permafrost degradation and runoff.In this study,the relationship between frost degradation and runoff and its variability over the last 30 years are investigated.The study uses the frozen depth data from the Manzhouli meteorological station for the period 1974—2006 and the monthly runoff data from four hydrological stations on the Hailaer River basin for the period 1974—2008.The result shows that the winter discharge has increased 13%-20% at the Hailaer,Bahou,and Honghuaerji three hydrologic stations,and no significant change is found at the fourth one(Yakeshi).The discharge ratio of February to November(Q2/Q11) has increased significantly,while the maximum frozen depth at the Manzhouli meteorological station has decreased about 50cm for the same time period.These results imply that the winter recession curve has shown a slowing trend mainly due to the effect of frost degradation under climate warming.The hydrologic impact of frost degradation would be explainable by the following three aspects.First,the degradation of frozen ground will lead to the increases in aquifer thicknesses,surface water infiltration amounts,and groundwater storages.Subsequently,the groundwater increment will increase the winter discharge.Second,the circulation of groundwater is moving much more slowly than the surface water does.The enlarged groundwater reservoir will lead to a longer river runoff recession.Third,the response of frost degradation to climate warming is a slow process and its effect on runoff variability is also a gradual one.