基于“配料法”的渠江流域短时强降水中尺度概念模型及物理量配置

Mesoscale Conceptual Model and Physical Quantity Allocation of Short-term Heavy Rainfall in the Qujiang River Basin Based on Batching Method

本文利用2010—2020年高空和地面观测资料,基于流型辨识法和配料法,建立了渠江流域短时强降水概念模型,对抬升条件、水汽条件和不稳定条件等物理量特征进行定量分析。结果表明:(1)渠江流域短时强降水按环流形势可分为3类6型,即副高边缘低槽类、高空低槽类、副高控制类三个大类,其中副高边缘低槽类分为低涡切变型、低空急流型和混合型,高空低槽类分为冷锋低槽型和短波槽型,副高控制类只有高空冷平流型。(2)副高边缘低槽类主要集中出现在6—9月,是发生最多的一类,占总个例数的64.5%;高空低槽类是3—5月和10—11月短时强降水的主要类别;副高控制类主要出现在8月,仅占1.7%。(3)副高边缘低槽类短时强降水具有范围大、时间长、降雨强的特点,高空低槽类短时强降水过程累计降水量小于副高边缘型,副高控制类短时强降水范围一般不大,但局地性强,通常还伴有雷电大风等对流性天气。(4)渠江流域短时强降水各类型的中尺度物理量阈值对于提高区域强降水预报水平具有一定的参考价值。

Using high-altitude and ground observation data from 2010 to 2020,and based on the flow pattern identification and batching methods,a conceptual model of short-term heavy precipitation in the Qujiang River Basin was established.The quantitative analysis was conducted on physical characteristics such as uplift conditions,water vapor conditions,and unstable conditions.The results show that:(1)The short-term heavy precipitation in the Qujiang River Basin can be divided into 3 categories and 6 types according to the circulation pattern,namely,the trough at the edge of the subtropical anticyclone,the high-level trough,and the subtropical anticyclone control category.The trough at the edge of the subtropical anticyclone can be divided into vortex-shear type,low-level jet type and mixed type.The high-level trough is divided into cold front-trough type and short wave trough type.The subtropical anticyclone control category only has high-level cold advection types.(2)The trough at the edge of the subtropical anticyclone mainly occurred from June to September,accounting for 64.5%of the total number of cases.The high-level trough type was the main category of short-term heavy precipitation from March to May and from October to November.The subtropical anticyclone control category mainly appeared in August,accounting for only 1.7%.(3)The short-term strong precipitation of the trough at the edge of the subtropical anticyclone has the characteristics of large range,long duration,and strong rainfall.The cumulative precipitation of short-term strong precipitation processes in high-level trough type is smaller than that in the trough at the edge of the subtropical anticyclone type.The range of short-term heavy rainfall controlled by subtropical anticyclone is generally not large,with strong locality and usually accompanied by convective weather such as lightning and strong winds.(4)The thresholds of various types of mesoscale physical quantities of short-term heavy rainfall in Qujiang River Basin have certain reference value for improving the forecast level of regional heavy rainfall.