第一篇：喜馬拉雅山北坡典型高山流域水文過程與氣候變化研究（本站推薦）

喜馬拉雅山北坡典型高山流域水文過程與氣候變化研究

摘要：全球變暖的大環境下，作為淡水最大儲存的冰川日益退縮，以冰川融水補給為主的河流直接受到影響，尤其在中國等亞洲地區。這類河流在我國主要分布在西部地區，冰川水資源是下游，尤其是干旱與半干旱區人民賴以生存和社會經濟可持續發展的生命線。喜馬拉雅山是我國以及印度、東南亞很多河流的發源地，由于冰雪融水占很大比重，所以對氣候變化比較敏感；同時這個區域廣泛分布著島狀多年凍土，凍土對徑流過程也有著不可忽視的影響，但在我國喜馬拉雅山一側冰川凍土水文對氣候變化響應的研究卻很少。本文選取我國喜馬拉雅山一側唯一具有長期水文氣象觀測資料的卡魯雄曲為典型區域，通過Mann-Kendall趨勢檢驗法，Sen坡度估計以及相關統計分析方法，分析了近20年河流水情，并與氣候特征結合來探討徑流變化的原因，所得結果對研究青藏高原水文氣象過程與我國東南亞乃至全球的天氣、氣候變化都有一定的指導意義。（1）卡魯雄曲流域近40年平均氣溫以0.38℃/10a的趨勢上升，高于西藏年均溫0.26℃/10a的增長率，更是明顯高于同期全國氣溫增長率（0.40℃/100a）和全球氣溫增長率（0.3~0.6℃/100a），且極端最高溫都出現在20世紀90年代。后十年氣溫（1994~2003年）比前十年（1983~1993年）升高0.5℃。（2）徑流對氣候變化的響應最靈敏（一年有8個月的增加趨勢通過α=0.05的顯著性檢驗），尤其是秋冬季的徑流（α=0.01）。后10年與前10年比較，徑流量增加了26%；不同月份徑流增加強度不同，10~2月增加了44%，7~9月增加了27%，3~6月增加了24%。（3）受冰川消融和季風降水的影響，不同月份的徑流受到的影響因素不同；但存在共性，即氣溫對徑流起著積極主導作用，而降水對徑流的影響則具有不確定性；根據已有資料建立了消融期（4~10月）置信度超過95%的徑流與氣候要素的統計方程，可進行未來情景預測。并采用未來不同氣候情景（α=0.02℃/a或α=0.052℃/a），根據已建立的統計方程，得出2050年和2100年可能的徑流變化，發現5月和10月的徑流增加最多。（4）非消融期（11~3月）徑流有不同程度的漲幅，突變發生在1990年左右。1月份增加最明顯，后10年比前10年增加了67%。遙相關分析表明1月份徑流與7~12月徑流有通過95%顯著性檢驗的相關性，前期月份共同作用使徑流變化更顯著，這是凍土區所特有的。（5）SRM在卡魯雄曲流域的模擬結果比較理想，說明SRM融雪徑流模型在冰川區域同樣適用；并且通過情景預測，在氣溫上升1℃的情況下，模擬的徑流沒有明顯提前，但流域徑流量整體明顯增大。

Abstract：The Karuxung catchment is a typical area and unique with a long term observations in the Tibet-Himalayas since 1983.The altitude of the basin varies widely from about 4,550 m to 7,200 m.Owing to high elevation, the alpine permafrost covers about 60% of the drainage area, which limit line is 5,100 m, above which underlay permafrost and below is seasonally frozen ground.Water supply of the Karuxung watershed is mainly from melt water and rainfall;therefore climate warming and precipitation increasing both have positive impacts to runoff.Mann-Kendall trend analysis, the Sen’s slope estimate and correlation analysis were employed to analyze data from Wengguo hydrometric station and Langkazi meteorological station.The results indicated that runoff, air temperature, precipitation and evaporation all have pictured significantly upward trends.Of which runoff change was the most sensitive to climate change, especially during fall and winter.It was concluded that a great number of trends were observed than were expected to occur by chance.In recent 20 years, the annual mean temperature has increased dramatically with a speed of 0.34℃ every 10 years, which was higher than the speed of Tibet region which was 0.26℃ every 10 year, and the extremely high temperature all appeared in the 1990s.For the air temperature, it in the pre-10 years was higher with 0.5℃ than that of the post-10 years, whereas the runoff has increased 26%.Different periods have different growth extent, it during October to February has increased 44%, July to September has increased 27%, and March to June has increased 24%.During ablation period, the runoff change was affected mostly by climate change from April to June, whereas the runoff was affected by air temperature and precipitation jointly when monsoon came, and the precipitation influenced the runoff with uncertainty.During non-ablation period, runoff change was more obviously as it was influenced by former months;the key supply was baseflow.The results indicated that the runoff in cold season all have figured out significantly increasing extents, of which runoff change in January was the greatest about 67%.Furthermore, the runoff in January had close correlations with the runoff from July to December at a significance level of 95%.Therefore, the runoff change in cold season was caused by the former months jointly, which was a characteristic of the permafrost effect.SRM was applied to the Karuxung watershed, and showed a very good result.In a warmer scenario with 1℃ increased daily air temperature, the runoff peak did not move forward, but the mount was enlarged.