Abstract:

Desert pavement is a surface layer with closely packed gravel that insets in a thin fine-grained vesicular soil horizon， and is important for the stability of the desert ecosystem. Based on the data of the field investigation and situ soil water infiltration in the northern desert of Linze Oasis in the Hexi Corridor， the characteristics of desert pavement and its influence on water infiltration are analyzed in this study. The results show that： （1） desert pavement is 0.50 cm thick with 4.61 mm size gravel， and its surface gravel coverage average 52.7%. （2） Compared to the soil profile below the desert clast， the mass water content of pavement is lower and 0.3%， but the gravel content of pavement is higher and 41.64%， with the declining trend from hill to oasis. Except for Sample 2， the bulk density in upper soil profile （0-5 cm） with pavement clast is higher than it in lower soil profile （5-50 cm）. （3） desert pavement can constrain the water infiltration， the steady-state infiltration increases from 2.35 mm·min^-1 to 3.69 mm·min^-1 when the pavement clast removed. （4） Steady-state infiltration of desert pavement has a significantly negative correlation with thickness and gravel content of pavement clast， a significantly positive correlation with gravel coverage and mass water content of pavement clast， and a positive correlation with grave size of pavement clast. This study is helpful to understand the hydrologic effect of desert pavement.

Key words: desert pavement, pavement clast, water infiltration, disk permeameter, Linze Oasis