This study aimed to investigate the effect of rainfall events on soil moisture. The results showed that evaporation, surface vegetation interception, and other losses caused <7.0 mm of rainfall to be available, which is insufficient to improve soil moisture, and thus these rainfall events may be regarded as ineffective. The maximum effective infiltration depth of a 0–7 mm rainfall event was 10 cm, and the maximum effective infiltration depths of 7–15, 15–29, 29–36 and 36–55 mm events were 20, 30, 40 and 50 cm, respectively. Only >55 mm of rainfall could infiltrate the soil below 50 cm. The soil surface moisture content of the 0–10 cm layer was highest at the end of the day of the rainfall event. The soil moisture content of the 10–20 cm and 20–30 cm layers was highest on the day after the end of the rainfall event. However, the soil moisture content of the 30–40 and 40–50 cm layers was highest 3 days after the end of the rainfall event. A binomial regression relationship was found between the soil moisture increase caused by unit rainfall and the initial soil moisture content of the 0–30 cm layer. With the increase of the initial soil water content, the soil moisture increase caused by unit rainfall first increased and then decreased and was greatest when the initial water content of the soil was between 5% and 12%. Rainfall on soil that was too dry or too close to the saturated state could not cause the soil moisture to increase.

这项研究旨在调查降雨事件对土壤水分的影响。结果表明，蒸发，地表植被截留和其他损失导致＜7.0 mm的降雨可用，不足以改善土壤水分，因此这些降雨事件可能被认为是无效的。0-7 mm降雨事件的最大有效渗透深度为10 cm，7-15、15-29、29-36和36-55 mm事件的最大有效渗透深度为20、30、40和50 cm ， 分别。只有> 55 mm的降雨才能渗入50 cm以下的土壤。降雨事件结束时，0–10 cm层的土壤表面水分含量最高。降雨事件结束后的第二天，土壤10-20厘米和20-30厘米的含水量最高。然而，降雨事件结束后三天，30-40和40-50 cm层的土壤水分含量最高。在单位降雨引起的土壤水分增加与0–30 cm层的初始土壤水分含量之间发现了二项式回归关系。随着土壤初始含水量的增加，单位降雨引起的土壤含水量先增加后减少，当土壤初始含水量在5％〜12％之间时最大。太干燥或太接近饱和状态的土壤上的降雨不会导致土壤水分增加。在单位降雨引起的土壤水分增加与0–30 cm层的初始土壤水分含量之间发现了二项式回归关系。随着土壤初始含水量的增加，单位降雨引起的土壤含水量先增加后减少，当土壤初始含水量在5％〜12％之间时最大。太干燥或太接近饱和状态的土壤上的降雨不会导致土壤水分增加。在单位降雨引起的土壤水分增加与0–30 cm层的初始土壤水分含量之间发现了二项式回归关系。随着土壤初始含水量的增加，单位降雨引起的土壤含水量先增加后减少，当土壤初始含水量在5％〜12％之间时最大。太干燥或太接近饱和状态的土壤上的降雨不会导致土壤水分增加。