基于CMIP5模式与VIC模型耦合的滦河流域未来气候及径流变化研究

Future Climate and Runoff Changes in the Luanhe River Basin Based on CMIP5 Coupled with VIC Model

滦河流域是京津冀地区重要的生态屏障,在全球变暖的背景下,研究滦河流域未来气候及径流变化情势对京津冀地区的发展具有重要意义。基于VIC模型模拟滦河流域历史径流,利用相关系数、中心均方根误差、标准差和均值构建CMIP5未来全球气候模式评价指标体系,并对其做归一化处理,从各模式中选取最优的降水、最高气温、最低气温及风速数据以分析滦河流域未来气候变化。采用Delta法进行气象要素空间降尺度,将VIC模型与CMIP5全球气候模式耦合,开展滦河流域未来径流变化情势分析。结果表明:VIC模型在滦河流域的径流模拟效果令人满意。在年际上,未来年降水量、日最高与最低气温均呈上升趋势,未来日平均风速无明显上升趋势。在年内分配上,与历史期同月份相比,未来月平均降水量有增有减,其中10月份增加率最高,达138.64%;未来月平均最高气温均升高,9月份变化最大,平均升高2.45℃;未来月平均最低气温平均升高3.24℃,其中2月份变化最大,平均升高4.45℃;不同月份未来风速有升有降,其中8月份变化最大,平均升高0.23 m/s,升高率达16.35%。未来期的多年平均流量为134.41 m^(3)/s,比历史期增加9.96%。未来年流量平均以10.2 m^(3)(/s·10 a)的速度波动上升。其中,2020s和2080s的年流量平均以12.8和28.9 m^(3)(/s·10 a)的速度波动上升,上升趋势显著。夏季径流占比由历史期的53%降至43%,冬季径流占比由7%升至12%。

The Luanhe River Basin plays an essential ecological role in the Beijing-Tianjin-Hebei region.In the context of global warming,it is momentous to study the future climate change and runoff pattern of the Luanhe River Basin for the development of the Beijing-Tianjin-Hebei region.In this thesis,the historical runoff of Luanhe River Basin is simulated based on VIC model.The CMIP5 future global climate model evaluation index system is constructed by using correlation coefficient,central root mean square error,standard deviation and mean value,and normalized.The optimal precipitation,maximum temperature,minimum temperature and wind speed data are selected from each model to analyze the future climate change in the Luanhe River Basin.The spatial downscaling of meteorological elements is carried out by using Delta Method,and the VIC model is coupled with THE CMIP5 global climate model to analyze the future runoff changes in the Luanhe River Basin.The results show that VIC model has a satisfactory effect on runoff simulation in the Luanhe River Basin.At the interannual level,annual precipitation,daily maximum and minimum temperature show an increasing trend in the future,while daily mean wind speed shows no obvious increasing trend.In terms of annual distribution,compared with the same month in the historical period,the average precipitation of the next month will increase or decrease,and the increase rate of October is the highest,reaching 138.64%.In the future,the average maximum temperature will increase,with the greatest change in September,with an average increase of 2.45℃.In the future,the mean minimum temperature will increase by 3.24℃on average,with the largest increase of 4.45℃in February.The future wind speed increases and decreases in different months,with the largest change in August,with an average increase of 0.23 m/s and an increase rate of 16.35%.The multi-year average flow of the future period is 134.41 m^(3)/s,increasing by 9.96%compared with the historical period.In the future,the average annual flow rate fluctuates at a rate of 10.2 m^(3)(/s·10 a).In the 2020s and 2080s,the annual flow will fluctuate at an average rate of 12.8 and 28.9 m^(3)(/s·10 a),with a significant upward trend.The proportion of runoff in summer decreases from 53%to 43%,and that in winter increases from 7%to 12%.