Understanding soil water dynamics and their influencing factors is an important basis for formulating efficient water-use strategies aimed at alleviating water stress, especially in areas with water shortages. In this research, six plots with different densities were designed to systematically analyze the influences of Phragmites australis density and groundwater level on soil water in a semiarid wetland. (1) The Phragmites australis density had a negative influence on the soil water in the 0-40 cm profile and from April to August. (2) The Phragmites australis density had a positive effect on the annual variation degree of the soil water storage. The water replenishment could be implemented in April and June for low and high Phragmites australis densities, respectively. (3) The groundwater level had a significant influence on the soil water content of the 0-50 cm layer, and the change was positively correlated with the Phragmites australis density. The influence of groundwater level on soil water was more influential than that of Phragmites australis density. (4) The suitable average groundwater depth for the 0%, 20%, 40%, 60%, 80% and 100% densities were 76 cm, 63 cm, 50 cm, 37 cm, 23 cm and 10 cm, respectively. The suitable average densities of Phragmites australis for the groundwater depth of 35 cm, 40 cm, 45 cm and 50 cm were 62%, 55%, 47% and 40%, respectively. This research can provide a theoretical support for the management of Phragmites australis density and groundwater level in the Baiyangdian wetland.

了解土壤水分动态及其影响因素是制定旨在缓解水资源压力的有效用水策略的重要基础，尤其是在缺水地区。本研究设计了六个不同密度的样地，系统分析了芦苇密度和地下水位对半干旱湿地土壤水分的影响。(1)芦苇密度对0-40 cm剖面和4-8月土壤水分有负面影响。(2)芦苇密度对土壤蓄水量的年变化程度有正向影响。低位和高位芦苇可在4、6月补水密度，分别。(3)地下水位对0~50 cm层土壤含水量有显着影响，且变化与芦苇密度呈正相关。地下水位对土壤水分的影响比芦苇密度的影响更大。(4) 0%、20%、40%、60%、80%和100%密度的适宜平均地下水深度分别为76 cm、63 cm、50 cm、37 cm、23 cm和10 cm。35 cm、40 cm、45 cm和50 cm地下水深度的芦苇平均密度分别为62%、55%、47%和40%。本研究可为芦苇的管理提供理论支持。 白洋淀湿地的密度和地下水位。