Welcome to Chinese Agricultural Science Bulletin,

Chinese Agricultural Science Bulletin ›› 2017, Vol. 33 ›› Issue (7): 148-152.doi: 10.11924/j.issn.1000-6850.casb16100104

Special Issue: 农业气象

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Warm Area’s Shear Rainstorm in Eastern Gansu: Characteristic Analysis

  

  • Received:2016-10-25 Revised:2016-12-14 Accepted:2016-12-19 Online:2017-03-16 Published:2017-03-16

Abstract: To improve the ability of forecasting and analyzing the rainstorm disaster, reduce the impact of rainstorm disaster on agriculture and people’s life and production, by using the data of warm area’s shear rainstorm on the ground and high altitude in Qingyang from 2007 to 2014, the authors analyzed the spatial and temporal distribution characteristics, influencing factors and causes of warm area’s shear rainstorm. The results showed that: temperature and humidity conditions had significant influence on the warm area’s shear rainstorm in Qingyang, usually the rainstorm occurred in the western Ning county, the junction of Qingcheng and Heshui, mid- western Huaci and southern Huan county and eastern Zhenyuan, which had suitable geographical and humidity conditions; contrasting with rainstorm in eastern Gansu happening in April to September, warm area’s shear rainstorm mainly concentrated in July and August, 85.7% of them happened in late July and late August; persistent southerly winds could last 3-7 days before warm area’s shear rainstorm in Qingyang, there would be an obvious jump on relative humidity and temperature; the strong instability energy was reflected on the T- logP chart and the Cape value was relatively big; falling area was mainly affected by topography and middle dry intrusion, with strong uncertainty, and happened near the shear line on both sides; the trigger system was mainly the warm shear line, it could be divided into the vortex type and southwest airflow type.