气候变化背景下黄河流域径流变化情势分析

Analysis of Runoff Variation in Yellow River Basin on the Background of Climate Change

依据实测资料和利用古树年轮等资料重建兰州站数百年径流量系列，采用周期叠加外延和分布式水文模型模拟等方法，分析了近期黄河中游降水特点，预测了河源区未来气温、降水量和径流量的变化情势。结果表明，20世纪70-90年代，黄河中游地区年均降水量低于多年平均值，而近8a（2000-2007年）则略高于多年均值。黄河源区唐乃亥以上区域，21世纪20年代、50年代和80年代日最高气温将在基准期基础上分别升高1．34—1．41℃、2．42-2．60℃和3．44—3．90℃，日最低气温则分别升高0．87—1．49℃、1．49—2．68℃和2．27-3．76℃；未来3个时期的降水量表现出一定的增加趋势，但是增幅不显著，分别比基准期增加3．47％、6．42％和8．67％。无论对于哪种情景，黄河源区在未来若干年内将可能出现持续增温趋势，而降水量变化幅度相对较小，这很可能导致未来水资源的紧张趋势进一步加剧。

Hundreds of years＇ runoff series of Lanzhou hydrological station was rebuilt based on measured data and old tree ring analysis. Precipitation characteristics were analyzed in the middle reaches of the Yellow River and the changes of future temperature, precipitation and runoff were forecasted using the method of distributed hydrological model and periodic extensional superposition. The results showed that precipitation in the middle reaches of the Yellow River was reduced timely comparing with that of long year average, but increased in recent eight years （from 2000 to 2007）. The highest daily tempera- ture will increase 1.34--1.41 ℃ , 2.42--2.60 ℃ and 3.44--3.90 ℃ and the lowest daily temperature will increase 0.87--1.49 ℃ , 1.49--2.68 ℃ and 2.27--3.76 ℃separately in upstream Tangnaihai hydrological station of the Yellow River source regions comparing with that of the reference period in 2020 s, 2050 s and 2080 s. The precipitation showed an increase trend in the future three periods, but the increase range is not clear. The precipitation will increase 3.47% , 6.42% and 8.67% respectively comparing with that of the reference period. For the above case, the temperature will increase constantly in the future years, but the precipitation range is not wide relatively, which will deteriorate the limited water resources.