新疆气候由暖干向暖湿转变的信号及影响

A STUDY ON SIGNALS AND EFFECTS OF CLIMATIC PATTERN CHANGE FROM WARM-DRY TO WARM-WET IN XINJIANG

目前的全球气候变暖导致了水循环加快 ,尤其干旱区水循环加快更加明显 ,降水和蒸发增加。自 19世纪末小冰期结束以来 ,新疆呈现出了与全球一致的变暖趋势 ,气候环境基本处于暖干状态之下。 1987年起新疆出现了气候转向暖湿的信号 ,尤以天山西部地区为强劲。降水量、雪冰消融量和河川径流量连续增加至今日 ,导致平原湖泊水位持续上升 ,面积逐年扩大 ,早己干涸的湖盆也出现生机。与此同时 ,洪水灾害连年发生 ,而且越来越凶猛 ,不断出现百年 ,以至千年的洪峰。此间 ,植被环境改善 ,绿洲春色盎然 ,沙漠化止步 ,沙尘暴锐减。这种气候转变前景如何 ,应该引起人们高度重视。这个问题直接关系到新疆以至大西北的经济发展、水利建设、洪旱灾害减灾、生态环境保护以及人民生活改善等。因而必须加强监测与研究 ,尽早做出正确预测 。

Located in inland and far from ocean, Xinjiang is famous for its vast deserts. The ecological environment here is extremely fragile owing to the aridity. Therefore, it is recognized that Xinjiang is a sensitive and affected area to global warming. Since the late of 19 century, the little ice age ended, a warming trend corresponding to global warming was taking place in Xinjiang. The water circulation has been quickening as the increasing of evaporation and precipitation in the world, especially in the arid land, during the process of global warming. Generally, the climatic condition was in the state of warm dry in this area. Since 1987, however, some signals of climatic pattern change from warm dry to warm wet have been occurring in Xinjiang, especially in the western Tianshan Mountains of China. The precipitation, melting water of snow and ice, river discharges have been increasing. The water levels of plain lakes rise successively and their areas enlarge yearly. Even several dried up lakes are revived. At the same time, the flood disasters occur continuously and the damages become larger and larger. The discharges of flood peaks reach to the highest in a century even centuries. During the period, desertification ceases to enlarge and days of sandstorm decrease owing to the improvement of the environment and the increasing of the vegetation. The oases are full of the beauty of spring. However, special attention should be paid to the future perspectives of this climatic pattern change, an issue that is directly related to the economic development, the hydrological infrastructure construction, the flood and drought disaster reduction, the eco environmental protection and the living standard improvement. Therefore, some further observation and deep researches must be conducted in order that correct prevision can be made out as early as possible and scientific basis can be put forward for the long range plan of the national economy.