未来气候情景下天山西部山区融雪径流变化研究

基于三种不同模式的CMIP5气象数据,采用互信息法挑选预报因子结合RBF神经网络模型,预测不同排放情景(RCP2.6、RCP4.5、RCP8.5)下未来气候变化下天山西部山区融雪径流的变化情况。对三种模式下不同排放情景预测出的未来径流量进行分析发现:(1)未来径流量在2020～2030年将持续上升,在2060年趋于稳定;未来径流量在非汛期有大幅度的增加而在汛期径流量减少;(2)通过灰色相关性分析找到未来不同模式不同情景下影响径流的主要相关因子,对各相关因子未来变化情况进行分析,发现径流在非汛期有大幅度的增加而在汛期径流量减少的主要原因是:非汛期的降水增加而蒸发减少或增加幅度不大;汛期降水减少而蒸发随气温升高导致汛期的径流量减少。

Change of Snowmelt Runoff in Western Tianshan Mountains under Future Climate Scenarios

Based on the meteorological data of three different models in CMIP5, the mutual information method was used to selectthe forecasting factors and the RBF neural network model was used to predict the changes of snowfall runoff in the western mountainousareas of Tianshan Mountains under different climate scenarios (RCP2.6, RCP4.5, RCP8.5). The results show that: (1) Thefuture runoff will continue to rise during 2020-2030, and be stable in 2060. In additon, the future runoff increases significantly innon-flood season and decreases in flood season; (2) The main factors affecting the runoff in different scenarios under differentmodes were analyzed by the grey correlation method. Besides, the future changes of the relevant factors were analyzed. It is foundthat the main reasons for the increase of runoff in non-flood season and the decrease of runoff in flood season are that the precipitationincrease while the evaporation decrease or increase slightly in the non-flood season, and the precipitation decrease while theevaporation increase with the temperature in the flood season.