关键词: 土壤水力参数, 海拔, 地形序列, 土壤持水能力, 土壤水库, 准噶尔西部山区

Abstract: To elucidate the characteristics of soil hydraulic properties in the Western Junggar Mountains and their variation along the elevational gradient, five soil profiles were selected along a topographic sequence spanning elevations from 471 m to 1 111 m in Yumin County, Tacheng Prefecture, Xinjiang, in April 2023. Basic physicochemical properties and soil water characteristic curves of these profiles were measured. The results indicated significant differences in basic physicochemical properties and hydraulic parameters among the soil profiles along the topographic sequence. Soil bulk density, mechanical composition, and organic matter content showed strong correlations with elevation. The high-altitude soil profiles were dominated by silt particles, while the low-altitude profiles were primarily composed of sand particles. The soil water characteristic curves exhibited a pattern of rapid initial decline, followed by a slower decrease, and finally stabilized with the increase of elevation. Soils at higher elevations demonstrated stronger water retention capacity. The soil hydraulic parameters (A) of the two high-altitude soil profiles [P1（1 111 m） and P2（1 071 m] were higher than those of the others in the same soil layer. As soil depth increased, the A value, saturated water content, field capacity, and available water capacity generally decreased. Altitude showed an extremely significant positive correlation with the A value (P<0.01).

Key words: soil hydraulic characteristics, altitude, topographic sequence, soil water retention capacity, soil reservoir, Western Junggar Mountains