复杂下垫面对四川一次暴雨影响的敏感性模拟研究  

Sensitivity Simulation Study of a Severe Rainfall Event in Sichuan Province under the Influence of Complex Underlying Surfaces

作　　者：梁沛乐 王磊[1] 李谢辉[1] 符梓霖 LIANG Peie;WANG Lei;LI Xiehui;FU Ziin(School of Atmospheric Sciences,Chengdu University of Information Technology,Chengdu 610225,Sichuan,China)

机构地区：[1]成都信息工程大学大气科学学院,四川成都610225

出　　处：《高原气象》2024年第5期1286-1301,共16页Plateau Meteorology

基　　金：第二次青藏高原综合科学考察研究项目(019QZKK0105);四川省科技计划项目(2022YFS0536);成都信息工程大学科技创新能力提升计划项目(YTD202301,KYTD202343)。

摘　　要：四川盆地下垫面复杂多样,暴雨频发,探究不同下垫面要素对区域性降雨的影响有着重要意义。本文利用美国国家环境预测中心全球再分析资料和不同类别的土地利用资料,其中包括MODIS(Moder‐ate Resolution Imaging Spectroradiometer)、USGS(United States Geological Survey)、2015年LUCC2015(Land use datasets in China 2015)和2015年GLASS(Global Land Surface Satellite)土地利用资料,使用WRF(Weather Research Forecast)模式对四川省一次暴雨事件进行数值模拟。通过四组土地利用实验和两组地形敏感性实验,研究了地表类型和地形高度对暴雨的影响。结果表明:不同土地利用类型试验对强降水区域影响较大,相比MODIS试验,USGS的降水区域更集中,强中心范围更大;LUCC2015试验在盆地东北部的降雨强度减弱,但降水区域更集中;由于土地利用较单一,GLASS试验的两个强降水中心强度均减弱,东北部的降水中心南移。不同土地利用对模拟的近地表气象要素场也产生影响:城市建筑群减少时,2 m温度降低0.5~1℃;植被覆盖度减少,导致2 m温度增加,10 m风速增强;地表粗糙度降低,10 m风速明显增强,为2~4 m·s^(-1)。地形对暴雨的影响显著,盆地西部山地降低后,由于缺少山脉阻挡,低层的水汽和能量更丰富,水汽和能量能够输送到四川更北的地区。低层气流在山前辐合加强,激发更强的气流抬升运动,导致降水强度增强、位置西移、范围更集中。相反,地形抬升后,山脉阻挡了南部的暖湿气流进入,致使水汽和能量分散,盆地西部和东部的气流辐合减弱,低层气流抬升减弱,最终降水强度减弱,降水面积减少。The Land surface of the Sichuan Basin is characterized by complexity and diversity,with frequent occurrences of heavy rainfall.This study utilizes global reanalysis data from the U.S.National Centers for Environmental Prediction and various categories of land use data,including default land use data from the WRF model,MODIS(Moderate Resolution Imaging Spectroradiometer),and USGS(United States Geological Survey).Additionally,the 2015 LUCC2015(Land use datasets in China 2015)datasets and the 2015 GLASS(Global Land Surface Satellite)land use datasets are incorporated.The WRF(Weather Research and Forecasting)model is used to simulate a heavy rainfall event in Sichuan Province.The impact of changes in land surface classification and variations in terrain height on heavy rainfall is discussed through four sets of land use experiments and two sets of terrain sensitivity experiments.The results indicate that the experiments involving different land use types have a significant impact on regions experiencing heavy precipitation.In comparison to the MODIS experiment,the precipitation distribution from the USGS experiment is more concentrated,with a larger coverage area for intense precipitation centers;the LUCC2015 experiment results in a reduction in rainfall intensity in the northeastern part of the Sichuan Basin,accompanied by a more concentrated precipitation distribution;the GLASS experiment simulation,characterized by a relatively uniform land use,results in a reduction in the intensity of both intense precipitation centers.Additionally,the precipitation centers in the northeastern part of Sichuan shift southward.Various land use types also exert influence on near-surface meteorological parameter fields.Through a comprehensive analysis of the various land use experiments,it is evident that a reduction in urban built-up areas results in a decrease in 2 m temperature by 0.5 to 1℃;the reduction in vegetation coverage results in an increase in 2 m temperature and an enhancement of 10 m wind speed;the decrease in surfac

关 键 词：暴雨 数值模拟 土地利用 地形 四川 

分 类 号：P458.121.1[天文地球—大气科学及气象学]