气候变化对黄河唐乃亥以上地区径流量的影响

根据黄河上游唐乃亥以上气候资料，统计分析了近50年气候变化特点，并以其与唐乃亥站径流关系为依据，建立天然径流量计算公式，计算分析了气候变化对唐乃亥站径流量的影响，结果表明：①近50年降水呈递减趋势，气温表现为显著升高特点；②20世纪90年代以来年平均气温较常年偏高0．5℃左右，而比前期升温达0．7℃～0．8℃；（3）近期降水量不仅较常年偏少，且比前期显著减少，尤其玛曲一带减少幅度达15．8％，并在时间上以6-9月最甚；④20世纪90年代以来天然年径流量与前期相比，减少了43．7亿m^3，气候变化所引起的减幅达20．2％。

Effect of climate variation on natural runoff in Tangnaihai and its upstream of the Yellow River

The climate variation characteristics were analyzed in the last 50-year according to the climate data of Tangnaihai and its upstream of the Yellow River. The natural runoff calculation formula was established in terms of the relationships between climate variation and natural annual of Tangnaihai, and the effect of climate variation on natural annual of Tangnaihai from 1990 s was calculated. The results showed that: The tendency of the natural runoff amounts for last 50 years were taken on degression and air temperatures were taken on upraising. The annual mean temperature since 1990 s was 0.5 higher than ordinary year temperature, and 0.70.8 higher than prior period. The recent precipitation was not only less than ordinary year precipitation but also decreased visibly than prior period precipitation before 1990 s. The natural annual runoff since 1990 s was decreased by 43.7x108 m3 than prior period precipitation and its decreasing amplitude resulted from climatic variation accounted for 20.2%.