中文摘要：

本文综述了关于黄河源区和上游地区气候变化及其对黄河径流影响的研究及其他有关研究，并进一步讨论了气候变化对黄河源区和上游径流以及源区生态和环境的影响。研究表明：从20世纪90年代初起黄河源区和上游年径流量锐减，它严重影响了黄河中、下游年径流量，并引起黄河下游在20世纪90年代断流天数的增加；并且还指出，黄河上游和源区从20世纪90年代初到新世纪初降水的减少可能是导致黄河源区和上游径流锐减的主要原因，而黄河源区降水强度的减弱对于黄河源区径流在20世纪90年代的锐减也有一定影响：此外，本文还表明了从20世纪80～90年代到新世纪初黄河源区气温的明显上升并没有导致此区域蒸发量的太大变化，它对径流变化影响不大，但对此地区植被和冻土退化有重要影响。

英文摘要：

The climate change in the source area and the upper reach of the Yellow River and its impact on the Yellow River runoff are reviewed. The impacts of climate change on the ecosystem and frozen soil in its source area are discussed further. It is shown that the annual run- off amount of the source area and the upper reach of the Yellow River significantly decreased from the early 1990s, which seriously affected the annual runoff amount of the middle and lower reaches of the Yellow River and caused the increase of drying-up days of the lower reach of the Yellow River during the 1990s. Moreover, the decrease of the pre- cipitation amount in the source area and the upper reach of the Yellow River from the early 1990s to the early 21th century may be a main rea- son led to the significant decrease of the runoff in the sources area and the upper reach of the Yellow River, and the weakening of the rainfall intensity in these areas during this period has an important impact on the significant decrease of the runoff in these areas. The obvious warming in the source area of this river from the 1980s to the early 21th century did not lead to a large change of the evaporation in this area. Thus, it may- be explain that the increase of air-temperature in the source area of the Yellow River slightly affect the runoff in this area. Besides, this obvious warming has an important impact on the degeneration of vegetation and frozen soil in the source area of the Yellow River.