气候变化影响下黄河上游梯级水库群未来发电量预测

Future power generation prediction of cascade reservoirs in upper reaches of the Yellow River under climate change

为分析气候变化影响下黄河上游大型水库入库来水过程及梯级发电量的时程变化规律,以黄河上游龙羊峡刘家峡梯级水库群为例,采用Mann-Kendall突变检验方法对唐乃亥和小川水文序列进行突变识别,在此基础上构建了考虑融雪过程的HBV水文模型,利用统计降尺度方法对CanESM2和GFDL_ESM2G两种气候模式3种气候变化情景(RCP2.6、RCP4.5和RCP8.5)下的降水、气温数据进行空间降尺度处理,并将其驱动水文模型预测未来入库来水过程,构建黄河上游梯级联合发电调度模型分析气候变化对未来发电调度过程的影响。结果表明:黄河上游径流序列突变年份集中于20世纪80年代,且2000年之后径流量显著减少;气候变化将导致未来(2021—2050年)汛期6—9月径流增加,非汛期径流显著减少;随着时间推移,不同气候变化情景下,龙羊峡和刘家峡两库的梯级发电量变化规律不同,RCP8.5气候变化情景下,气候模式不确定性对其影响最大。

In order to analyze the inflow process of large reservoirs in the upper reaches of the Yellow River and the time history variation law of cascade power generation under the influence of climate change,the Longyangxia and Liujiaxia cascade reservoirs in the upper reaches of the Yellow River were taken as examples,and Mann-Kendall method was used to identify the abrupt change of the Tangnaihai and Xiaochuan hydrological series.On this basis,the HBV model considering the snow melting process was constructed,and the statistical downscaling method(SDSM)was used to analyze the CanESM2 and GFDL_ESM2G climate models.The rainfall and temperature data of three climate change scenarios(RCP2.6,RCP4.5 and RCP8.5)was downscaled in space and was used to drive hydrological model to predict future runoff.Finally,a cascade joint generation scheduling model in the upper Yellow River was constructed to reveal the impact of climate change on future generation scheduling process.The results show that the mutation years of runoff series in the upper Yellow River are concentrated in the 1980s,and the runoff decreases significantly after 2000.From 2021 to 2050,climate change will increase the runoff from June to September,and decrease the runoff in non-flood period.With the passage of time,the change law of cascade power generation of the Longyangxia and Liujiaxia Reservoirs is different.Under RCP8.5,the uncertainty of climate model has the greatest impact on the difference.