The frequency of extreme events such as droughts is increasing due to climate change. Grassland ecosystems are extremely sensitive to drought. This study aims to analyse how droughts respond to meteorological factors, establish a method to quantitatively evaluate the threshold values of key meteorological factors that can induce drought in different time periods, and explore a drought prediction model applicable to the Xilinguole Grassland. The Xilinguole Grassland has experienced an obvious aridification trend, with notable fluctuations in short dry and wet periods and the probability of drought (generally ranked in the order of moderate drought > light drought > severe drought > extreme drought). The Xilinguole Grassland is expected to face more intense drought conditions in the next 5 years. Among the meteorological elements, temperature, precipitation, water vapor pressure and solar radiation are the key factors influencing drought. Both short-term and long-term changes in precipitation and temperature have a strong influence on drought. Short-term changes in water vapor pressure have a significant impact on drought. Drought is sensitive to extreme climate events and is most sensitive to the influence of meteorological factors in May–September, particularly in July. In July, drought can be induced by any of the following: monthly precipitation below 50 mm, an average temperature above 23 °C, sunshine percentage above 69%, a monthly sunshine duration above 319 h, or an average water vapor pressure below 12 hPa. In addition, Markov chain modelling is a feasible approach for predicting drought in the Xilinguole Grassland. This study provides a scientific basis for drought prevention and control.

由于气候变化，干旱等极端事件的频率正在增加。草原生态系统对干旱极为敏感。本研究旨在分析干旱对气象因子的响应方式，建立定量评价不同时间段引起干旱的关键气象因子阈值的方法，探索适用于锡林郭勒草原的干旱预测模型。锡林郭勒草原呈现明显的干旱化趋势，干湿期短、干旱概率（一般按中旱>轻旱>重旱>特旱排序）波动明显。预计未来5年，锡林郭勒草原将面临更加严重的干旱条件。在气象要素中，温度、降水、水汽压和太阳辐射是影响干旱的关键因素。降水和温度的短期和长期变化对干旱都有很强的影响。水汽压的短期变化对干旱有显着影响。干旱对极端气候事件敏感，5-9月，尤其是7月对气象因素的影响最为敏感。7 月，干旱可由以下任何一种诱发：月降水量低于 50 毫米，平均气温高于 23 °C，日照率高于 69%，月日照时数高于 319 小时，或平均水蒸气压低于 12 hPa . 此外，马尔可夫链建模是预测锡林郭勒草原干旱的一种可行方法。