不同降雨量及雨强条件下兰州南山人工侧柏林土壤水分入渗规律

[目的]降雨是干旱半干旱地区土壤水分的主要来源，将野外观测和模型模拟相结合研究降雨入渗规律，可以更系统地掌握土壤水分亏缺状况。[方法]通过定点观测，应用Hydrus-1d模型对兰州南山人工侧柏林土壤水分动态变化进行模拟，评估模型在干旱区的适用性，分析不同降雨条件下土壤水分响应状况和入渗机制。[结果] Hydrus-1d模型在兰州南山人工侧柏林有较好的适用性，且深层模拟效果更优。降雨量<30 mm时，10 cm处土壤含水量对降雨响应最为强烈，30,50 cm处受降雨影响相对较小且有明显的滞后，70 cm以下没有响应；降雨量>8.2 mm时存在湿润峰。模拟期内，最大入渗深度为70 cm,最大入渗量为23.7 mm,入渗深度随时间增加而入渗量和入渗速率却随时间延长而减小。降雨量与入渗量、入渗深度和入渗速率呈显著正相关(p<0.05)。降雨量<20 mm时，降雨强度对入渗量、入渗深度和入渗速率存在显著影响。[结论]使用Hydrus-1d模型可以较好地模拟兰州南山人工侧柏林土壤水分动态变化并计算入渗量、入渗速率和入渗深度，且分析发现降雨量对该地土壤水入渗过程的影响更显著。

Soil Water Infiltration of Artificial Platycladus orientalis of Nanshan Mountain inLanzhou Under Different Rainfall and Rainfall Intensity

[Objective] Precipitation is the main source of soil water in arid and semi-arid regions. By combining field observation and model simulation to study the regularity of rainfall infiltration, the soil water deficit can be mastered more systematically. [Methods] Through fixed point observation, the Hydrus-1d model was applied to simulate the dynamic change of soil water in Platycladus orientalis on the artificial of Nanshan Mountain in Lanzhou, evaluate the applicability of the model in arid region, and analyze the soil water response and infiltration mechanism under different rainfall conditions. [Results] The Hydrus-1d model had good applicability in the artificial side of Nanshan in Lanzhou, and the deep simulation effect was better. When the rainfall was less than 30 mm, the soil moisture content at 10 cm has the strongest response to rainfall, while the influence of rainfall at 30 and 50 cm was relatively small and had an obvious lag, and there was no response below 70 cm. There was a wetness peak when the rainfall was more than 8.2 mm. During the simulation period, the maximum infiltration depth was 70 cm and the maximum infiltration volume was 23.7 mm. The infiltration depth increased with time, while the infiltration volume and infiltration rate decreased with time. Rainfall was positively correlated with infiltration volume, infiltration depth and infiltration rate (p＜0.05). When the rainfall was less than 20 mm, the rainfall intensity had a significant effect on the infiltration amount, infiltration depth and infiltration rate. [Conclusion] The Hydrus-1d model can be used to simulate the dynamic change of soil water in Platycladus orientalis on the artificial of Nanshan in Lanzhou and calculate the infiltration amount, infiltration rate and infiltration depth. Moreover, it is found that the rainfall has a more significant effect on the soil water infiltration process.