Analysis of Drought in Poyang Lake

[Objective] The drought situation and causes in Poyang Lake were analyzed.[Method] In response to the drought in Poyang Lake in ten years ago and in recent 10 years,the causes of drought in Poyang Lake were discussed.[Result] Drought occurred frequently in Poyang Lake and the consecutive serious drought occurred now and then.The water level in Poyang Lake since 21st century was lower.The drought in Poyang Lake was due to reduction of precipitation,low water level in Yangtze River and 'five lakes',hydraulic project,industrial and agricultural water increase and other aspects.[Conclusion] The study provided theoretical basis for the formulation of drought prevention measures by relevant departments.

Spatio-Temporal Analysis of Drought in the North-Eastern Coastal Region of Vietnam Using the Standardized Precipitation Index (SPI)

Spatio-temporal analysis of drought provides valuable information for drought management and damage mitigation. In this study, the Standardized Precipitation Index at the time scale of 6 months (SPI-6) is selected to reflect drought conditions in the North-Eastern coastal region of Vietnam. The drought events and their characteristics from 1981 to 2019 are detected at 9 meteorological stations and 10 Chirps rainfall stations. The spatio-temporal variation of drought in the study region is analyzed on the basis of the number, duration, severity, intensity, and peak of the detected drought events at the 19 stations. The results show that from 1981 to 2019 the drought events mainly occurred with 1-season duration and moderate intensity and peak. The number, duration, severity, and peak of the drought events were the greatest in the period 2001-2010 and were the smallest in the period 2011-2019. Among the 19 stations, the drought duration tends to decrease at 11 stations, increase at 7 stations, and has a slight variant at 1 station;the drought severity tends to decrease at 14 stations, increase at 4 stations, and has not a significant trend at 1 station;the drought intensity tends to decrease at 17 stations, increase at 1 station, and has a slight variant at 1 station;and the drought peak tends to decrease at 18 stations and increase at 1 station.

Analysis of the First Soaking Rain Process in Lanzhou City in 2011

[Objective]The research aimed to analyze the first soaking rain process in Lanzhou in 2011.[Method]By diagnostic analyses on weather scale,meso-scale system and physical quantity when the first soaking rain weather happened in Lanzhou City in 2011,formation reason and physical quantity characteristics of the soaking rain weather were discussed.[Result]Combination of the plateau low vortex and westerly cold trough was influence system of the first soaking rain.There was a southwest-southeast airflow from Sichuan Basin to Hexi in front of the trough at 700 hPa.It was commonly referred to as ＂ inverted-buckle wind＂,and provided sufficient water vapour for occurrence and maintaining of the precipitation.Convergence at the low layer and divergence at the high layer were favourable for vertical motion.Analyses on physical quantity and meso-scale system also proved important role of the ＂ inverted-buckle wind＂ at the low layer.[Conclusion]The research provided reference for real-time forecast business of the long drought turning rain in spring.