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| 中国西北气候由暖干向暖湿转型的特征和趋势探讨 | |
| 引用本文： | 施雅风,沈永平,李栋梁,张国威,丁永建,胡汝骥,康尔泗.中国西北气候由暖干向暖湿转型的特征和趋势探讨[J].第四纪研究,2003,23(2):152-164. |
| 作者姓名： | 施雅风 沈永平 李栋梁 张国威 丁永建 胡汝骥 康尔泗 |
| 作者单位： | 1. 中国科学院寒区旱区环境与工程研究所,兰州,730000 2. 新疆维吾尔自治区水文水资源局,乌鲁木齐,830010 3. 中国科学院新疆生态与地理研究所,乌鲁木齐,830011 |
| 基金项目： | 中国科学院知识创新工程重大项目 (批准号 :KZCX1- 10 - 0 6 |
| 摘 要： | 由于全球显著变暖和水循环加快,使得中国西北主要是新疆地区于1987年气候发生突然变化,随着温度上升,降水量、冰川消融量和径流量连续多年增加,内陆湖泊水位显著上升,洪水灾害也迅猛增加,同时,植被有所改善,沙尘暴日数锐减,从而改变了19世纪末期至20世纪70年代的变暖变干趋势.以降水量增加超过蒸发量增加所导致的径流量增长及湖泊水位上升作为气候向暖湿转型的主要标准,西北地区目前的气候变化可分为3个区域,即1)显著转型区;2)轻度转型区;3)未转型区.作者初步认为,西北气候向暖湿转型可能是世纪性的,预期西北东部在21世纪上半期也会向暖湿转变,但预测有较大的不确定性. |
| 关 键 词： | 气候变化 暖干 暖湿 气候转型 |
| 收稿时间： | 2002-12-18 |
| 修稿时间： | 2002年12月18 |
DISCUSSION ON THE PRESENT CLIMATE CHANGE FROM WARM-DRY TO WARM WET IN NORTHWEST CHINA |
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| Institution: | Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000; Bureau of Hydrology and Water Resources of Xinjiang Uygur Autonomous Region, rmqi 830010; Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, rmqi 830011 |
| Abstract: | Under the global warming, mainly in northwest China, the climate was basically characterized by the development of warm dry since the end of the little ice age until 1980s. A climatic mutation to warm wet happened in 1987. Since 1980s, air temperature has been increasing more rapidly. The average annual temperature during 1987 to 2000 had risen by 0.7℃ as compared with that during 1961 to 1986. Nevertheless, with the rising of temperature, precipitation and glacial melt water increase rapidly widespread. As compared with the period from 1961 to 1986, the average precipitation during 1987 to 2000 increased by 22% in the north Xinjiang, 33% in the south Xinjiang, and 10% to 20%, the middle and west Hexi Corridor area and some areas in the Qinghai Xizang Plateau, but most of the increasing precipitation falled on the Tianshan Mountains, the Qilian Mountains and other mountains with few actual records. For the increase of glacial melt water, No. One glacier at the source area of the rmqi River which has had field measurements and monitoring for several decades is taken as an example, the average annual melt water from 1985 to 2001 increased by 84.2% as compared with that during the years from 1958 to 1985. Whereas in the east region of northwest China, the conditions were in the opposite, it was still under the warm dry climate, precipitation decreasesd by 5% to 15% and the draught occurred frequently during the compared periods as above mentioned. Along with the increase of precipitation, the hydrological conditions and ecological environment were also correspondently changed. Most rivers in Xinjiang, the rivers at the middle and west Qilian Mountains of Gansu Province and at the southeast Qaidam Basin of Qinghai Province had experienced the trend of annual runoff increase since 1987, and the increase range was averaged at more than 5%, and was above 20% in most regions and the maximum increase range arrived at 40% from the years of 1956 to 1986 to the years of 1987 to 2000. The lake levels of the most influenced inland lakes by the increase of precipitation, such as the Bosten Lake and the Ebinur Lake, had continuously and rapidly risen since 1987. The lake level of Bosten Lake was risen with 4.5m from 1987 to 2002, exceeding the highest lake level during 1950s. The area of wide and shallow Ebinur Lake had been enlarged from 499km 2 in 1987 to 1 064km 2 in 2002, resuming the high lake level in 1957. Along with increase of precipitation, flood disasters happened frequently. In the existing records of flood disasters, the most serious ones occurred in 1987, 1996 and 2002, and the damage of 1996 flood disaster was extremely serious in Xinjiang. However, the climate change from warm dry to warm wet brings much more benefits than harms. The mean annual mountain water resources of Xinjiang during the years from 1987 to 2000 was increased by 7%, about 62.1×10 8m 3/a, as compared with that during the years from 1956 to 1986. The vegetation index was obviously increased in the area of north and west Xinjiang, where precipitation increased in a larger amount. In northern part of China, especially in the Xinjiang area, the days of sand dust storms were rapidly decreased because of the reduction of strong windy days. Above mentioned evidences indicate that the regional climate of northwest China had showed the trend climate change from the warm dry pattern to the warm wet pattern. Through comprehensive evaluation and analysis of the evidences and signals, the present climate change of northwest China can be classified into three regions. The first is the notable change region of climatic pattern with marked becoming wet, mainly in the north Xinjiang, the Tianshan Mountains and their both sides, the west Tarim Basin, the down course area of the Yarkant River, west and central part of the Qilian Mountains, and the area of southwest Qaidam Basin.The west boundary of this region should go into the Central Asia countries where the range is difficult to determine because of the lack of information. |
| Keywords: | climate change warm dry warm wet change of climatic pattern |
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