气候变化对高寒山区流域径流量的模拟及预测

Simulation and Prediction of Runoff in Cold Alpine Basins under Climate Change Conditions

柴达木盆地气候干旱、水资源缺乏、生态脆弱,盆地周围的高寒山区是其重要的水资源形成区。关注柴达木盆地高寒山区流域未来气候变化及相应径流变化具有重要意义,然而相关研究较少。本研究选取柴达木盆地东北部典型高寒山区流域—巴音河上游祁连山区,采用局部缩放法和方差缩放法,基于实测降水、温度数据对CMIP6下BCC-CSM2-MR模式SSP1-2.6、SSP2-4.5、SSP5-8.53种气候情景未来气候变化数据进行校准,将校准后的气候数据与SWAT模型耦合,模拟及预测历史及未来时期气候变化对巴音河出山径流的影响。结果表明,SWAT模型对巴音河出山径流的模拟效果满足评价标准,其适用性较好;巴音河上游祁连山区在3种气候情景下,2015—2100年降水量、最高温度、最低温度、出山径流量均增加,暖湿化趋势较为明显;3种情景下,2015—2100年巴音河流域地表径流将呈现先增加后减少的趋势。侧向流、地下径流、总产水量、融雪量将呈现增加趋势。研究结果可为柴达木盆地水资源管理和可持续发展提供科学依据和理论支撑。

The Qaidam Basin is characterized by arid climate,water scarcity,and ecological fragility,while the alpine mountainous areas around the basin are important areas for the replenishment of water resources.It is of great significance to study the influence of climate change on runoff changes in the alpine mountainous areas of the Qaidam Basin.However,related researches are rare.This study selected a typical alpine mountainous river basin in the northeast of the Qaidam Basin,the upper reaches of the Bayin River,Qilian Mountain.Firstly,local intensity scaling of precipitation,and variance scaling of temperature were used to calibrate the climate change data in three climate change scenario modes(SSP1-2.6,SSP2-4.5,SSP5-8.5)under the BCC-CSM2-MR model of CMIP6 based on observed precipitation and temperature data.Then,the calibrated climate data was coupled with the SWAT model.Finally,the impact of climate change on the runoff of the Bayin River in historical and future periods was simulated and predicted.The results indicated that the SWAT model performed good in simulation of historical streamflow in the mountainous Bayin River catachment;In Bayin River catchment,the precipitation,maximum temperature,minimum temperature,and the streamflow generated in the mountainous areas under the three scenarios from 2015 to 2100 showed an increasing trend.The climate in this area showed a warming and wetting trend from 2015 to 2100;Under the three scenarios,the surface runoff of the Bayin River catchment showed an increasing and then decreasing trend from 2015 to 2100.The lateral flow,groundwater flow,total water yield and snowmelt showed an increasing trend.The research results can provide scientific basis and theoretical support for water resource management and sustainable development in the Qaidam Basin.