1.The Pearl River Water Conservancy Research Institute,The Pearl River Water Resources Commission;2.School of Environment,Jinan University;3.College of Life Science and Technology,Jinan University
以北江流域为研究对象,利用VIC(Variable Infiltration Capacity)模型与13个CMIP5全球气候模式降尺度结果耦合构建了流域水循环预测模型。基于SESR(Standardized Evaporative Stress Ratio)指数预测了未来时期(2021-2050)三种排放情景下(RCP2.6、RCP4.5、RCP8.5)北江流域骤发干旱(简称“骤旱”)特征(频次、历时、强度)变化及不确定性。结果表明：①所构建的流域水循环预测模型在北江流域具有较高的模拟精度(纳什效率系数> 0.93),能较好地再现径流的年际和年内变化特征。②与基准期(1971-2000)相比,未来骤旱频次在空间上主要呈西部减少、东部增加的特征,且增幅随排放情景上升而增加(< 80%),流域东北部和南部地区预计会遭遇强度更高、历时更长的骤旱过程。③气候模式的不确定性呈现较强的空间异质性,且不同骤旱特征预测的不确定性在空间上有较大的差异。
Taking the Beijiang River basin as the study area, a water cycle prediction model was constructed by coupling the Variable Infiltration Capacity (VIC) model with the downscaling results of 13 CMIP5 global climate models. Then the Standardized Evolutionary Stress Ratio (SESR) index was used to predict the main characteristics (frequency, duration, and intensity) of flash drought and the corresponding uncertainties in the Beijiang River basin under three emission scenarios (RCP2.6, RCP4.5, and RCP8.5) in the future (2021-2050). The results show that the VIC model has good runoff simulation accuracy (Nash efficiency coefficient>0.93) in the Beijiang River basin, and can better reproduce the interannual and intra-annual variations of runoff. Compared with the baseline (1971-2000), the frequency of flash drought in the future (2021-2050) is generally characterized by a spatial distribution of decreasing in the west and increasing in the east, and the increase in frequency tends to be larger under the higher scenarios (<80%). The northeast and southern regions of the basin are expected to encounter flash drought events with higher intensity and longer duration. The uncertainty of global climate models shows strong spatial heterogeneity, and the projection uncertainty of different flash drought characteristics varies greatly in space.