1- , Shahid Beheshti University 2- Faculty of Biological Sciences and Technology, Shahid Beheshti University, Tehran, Iran
Abstract: (17 Views)
In this study, the influence of geomorphological forms and processes of the alluvial fan surfaces on the soil hydraulic conductivity in the alluvial fan located in the southeast of Shah Ghaib Salt Dome, Larestan, was evaluated. First, the border of the study area alluvial fan was determined using Google Earth images and field observation. After identification of fan border and their surfaces (young, old and fossil), a total number of 72 soil samples in different positions (apex, middle, and toe), and different landforms (interfluve, channel, bar, and swale) were collected to determine physico-chemical properties of soils. Soil hydraulic conductivity (K) was calculated based on the (Saxton et al., 1986) method. Then, the relationship of this parameter with soil texture, organic carbon, soil acidity, soil moisture percentage, and soil water retention was analyzed. The results showed that the hydraulic conductivity of the soil is higher in the channels and swales compared to the interfluves and bars. Also, the mean of hydraulic conductivity of the soil is higher on the old surface than the fossil and young surfaces. The surface of interfluves has higher clay% and silt% due to the long-term weathering of alluviums, resulting in increased soil hydraulic conductivity. The mean K value is higher in the toe (2.90) than in the middle (2.21) and apex (1.74) of the fan. The Soil hydraulic conductivity is not the same in different positions and landforms due to changes in soil texture, morphology, and surface processes of the alluvial fan. Overall, landforms, processes, and geomorphic positions of the alluvial fan surface affect the soil texture, and the soil texture is the main factor in the hydraulic conductivity changes of the studied alluvial fan surface.
Azizi S B, Bahrami S, Khaleghi S, Mehrabian A. Evaluation of the soil hydraulic conductivity and its relationship with the surface geomorphology of the Shah Ghaib alluvial fan in Larestan. جغرافیایی 2025; 25 (89) :140-162 URL: http://geographical-space.iau-ahar.ac.ir/article-1-4123-en.html