Yan Ma, Youqi Wang, Chengfeng Ma, Cheng Yuan, Yiru Bai
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引用次数: 0
Abstract
The eastern foothills of the Helan Mountains in China are a typical mountainous region of soil and gravel, where gravel could affect the water movement process in the soil. This study focused on the effects of different gravel contents on the water absorption characteristics and hydraulic parameters of stony soil. The stony soil samples were collected from the eastern foothills of the Helan Mountains in April 2023 and used as the experimental materials to conduct a one-dimensional horizontal soil column absorption experiment. Six experimental groups with gravel contents of 0%, 10%, 20%, 30%, 40%, and 50% were established to determine the saturated hydraulic conductivity (Ks), saturated water content (θs), initial water content (θi), and retention water content (θr), and explore the changes in the wetting front depth and cumulative absorption volume during the absorption experiment. The Philip model was used to fit the soil absorption process and determine the soil water absorption rate. Then the length of the characteristic wetting front depth, shape coefficient, empirical parameter, inverse intake suction and soil water suction were derived from the van Genuchten model. Finally, the hydraulic parameters mentioned above were used to fit the soil water characteristic curves, unsaturated hydraulic conductivity (Kθ) and specific water capacity (C(h)). The results showed that the wetting front depth and cumulative absorption volume of each treatment gradually decreased with increasing gravel content. Compared with control check treatment with gravel content of 0%, soil water absorption rates in the treatments with gravel contents of 10%, 20%, 30%, 40%, and 50% decreased by 11.47%, 17.97%, 25.24%, 29.83%, and 42.45%, respectively. As the gravel content increased, inverse intake suction gradually increased, and shape coefficient, Ks, θs, and θr gradually decreased. For the same soil water content, soil water suction and Kθ gradually decreased with increasing gravel content. At the same soil water suction, C(h) decreased with increasing gravel content, and the water use efficiency worsened. Overall, the water holding capacity, hydraulic conductivity, and water use efficiency of stony soil in the eastern foothills of the Helan Mountains decreased with increasing gravel content. This study could provide data support for improving soil water use efficiency in the eastern foothills of the Helan Mountains and other similar rocky mountainous areas.
期刊介绍:
The Journal of Arid Land is an international peer-reviewed journal co-sponsored by Xinjiang Institute of Ecology and Geography, the Chinese Academy of Sciences and Science Press. It aims to meet the needs of researchers, students and practitioners in sustainable development and eco-environmental management, focusing on the arid and semi-arid lands in Central Asia and the world at large.
The Journal covers such topics as the dynamics of natural resources (including water, soil and land, organism and climate), the security and sustainable development of natural resources, and the environment and the ecology in arid and semi-arid lands, especially in Central Asia. Coverage also includes interactions between the atmosphere, hydrosphere, biosphere, and lithosphere, and the relationship between these natural processes and human activities. Also discussed are patterns of geography, ecology and environment; ecological improvement and environmental protection; and regional responses and feedback mechanisms to global change. The Journal of Arid Land also presents reviews, brief communications, trends and book reviews of work on these topics.