Precipitation Characteristics of an Abrupt Heavy Rainfall Event over the Complex Terrain of Southwest China Observed by the FY-4A Satellite and Doppler Weather Radar

Abstract

On 22 July 2019, mesoscale convective systems (MCSs) with an abrupt heavy rainfall event (AHRE) hit Shuicheng County of Guizhou Province in Southwest China causing landslide and debris flow secondary disasters. The AHRE over the complex terrain of Shuicheng County had differences in location and intensity during two stages of the event. The two stages could be divided into different rainfall types (topographic rainfall and synoptic-weather-related rainfall) according to the spatiotemporal distribution and organization of MCSs based on surface and midlevel environmental field conditions. During the topographic rainfall stage, smaller meso-γ-scale (2–20 km) convective cells with lower echo-top heights (6–10 km) occurred along the windward slope of the primary mountain peak. During the synoptic-weather-related rainfall stage, a meso-β-scale (20–200 km) convective echo band with higher echo-top heights (10–14 km) occurred in the valley of the region. An adverse wind area (AWA) with distinct convergence of radar radial velocity existed over Shuicheng County. A formation mechanism analysis of the AHRE showed that topographic rainfall occurred in the warm and moist area, while synoptic-weather-related rainfall occurred due to local convergence and the intrusion of a cold tongue. Compared to the early stage, the cold tongue from the higher terrain superimposed over the warm sector at the base of major mountain ranges appeared to strengthen the rainfall.

Comprehensive Comparisons of State-of-the-Art Gridded Precipitation Estimates for Hydrological Applications over Southern China

“…As shown in Table 1, benefiting from the short latency time (9 hours for FY-4A, 1 hour for PERSIANN-CCS, 2 months for ERA5-Land, 3 days for GSMaP, and 3.5 months for IMERG), FY-4A has more potential for use in real-time hydrological applications than IMERG [16,[42][43][44]. Considering the shortcomings of the FY-4A in estimating heavy rainfall with large errors, the algorithm should be improved in the future to improve the monitoring ability for heavy rainfall so that the technique can be optimized for weather forecasting and flood warning [45].…”

Response of Extreme Rainfall to Atmospheric Warming and Wetting: Implications for Hydrologic Designs Under a Changing Climate

“…The maximum precipitable water is 70 mm, indicating that the record‐breaking rainfall occurs in an extremely moist and unstable environment over central China. Extreme rainfall at small temporal and spatial scales are also closely tied to the spatial organization of mesoscale convective storm cells (S. S. Li et al., 2020; Lochbihler et al., 2017; Luo et al., 2014). This involves the impact of regional topography and its interactions with the location of the convergence zones.…”

Development Characteristics and Causes of a Fatal Landslide Occurred in Shuicheng, Guizhou Province, China

“…Under the condition of high hydrostatic pressure, the original structure of basalt rock masses is destroyed, and the individual joints and fissures are connected to form larger fissures. The cracks formed by the destruction are quickly filled with groundwater, which continue to destroy the rock structure and further weaken the strength of the soil until the landslide occurrence when the rock masses are sheared out from the high elevation, causing a huge disaster [46][47][48].…”