Responses of soil moisture content to rainfall events and its influencing factors at Yujia Mountain

Abstract

Objective The response characteristics and influencing factors of soil moisture content under individual rainfall events at the test site of Yujia Mountain in Wuhan, China, were studied to provide a scientific basis for subsequent studies on groundwater storage changes in the unsaturated and saturated zones. Methods Based on the continuous field monitoring data of rainfall, groundwater level and soil moisture content, the dynamic changes in soil moisture content in four typical profiles and their response characteristics to six rainfall events were analysed. Taking the S4 profile as an example, the dominant factors of the response amplitude of soil moisture content were identified using the grey correlation method. Results Compared with the higher position of Yujia Mountain, the foot of the southern and northern slopes is lower, with a shallow water table, fine soil particles, and good sorting. As a result, the mean value of the soil moisture content was larger, and the coefficient of variation was smaller. The soil moisture content and initial response time of the four profiles did not increase systematically with increasing burial depth, reflecting the strong heterogeneity of the soil profiles in the study area. The correlation analysis between the response amplitude of soil moisture content and the four influencing factors showed that the average and maximum rainfall intensities were the dominant factors. Conclusion The two soil profiles located in the experimental building at the foot of the southern slope are strongly affected by human construction activities, surrounding greening and watering. The response characteristics and main influencing factors of soil moisture content should be comprehensively analysed based on long-term monitoring data in the future.

Keywords

• rainfall events
• soil moisture content
• grey correlation method
• rainfall intensity
• dominant factor