Group 1 - The Central Meteorological Administration issued a blue warning for sandstorms due to strong winds from cold air, predicting dust storms in several regions including southern Xinjiang and parts of Inner Mongolia and Gansu from May 4 to May 5 [1] - Gansu Province Meteorological Bureau activated a level IV emergency response for the sandstorm weather on May 3 [2] - Several scenic spots in Gansu, including Yangguan and Yumenguan, announced temporary closures due to low visibility caused by dust storms [5][6] Group 2 - The Mingsha Mountain Crescent Spring scenic area in Dunhuang canceled a large concert event due to sudden severe sandstorm conditions on May 3, apologizing to visitors for the inconvenience [8][11] - A ticket refund guarantee mechanism was initiated to minimize visitor losses due to the event cancellation [9] - Historical data indicates that spring is a peak season for sandstorm occurrences in China, with about 80% of such events happening between March and May, which can severely impact air quality and daily life [16]