Research on the Application of Palm Mat Geotextiles for Sand Fixation in the Hobq Desert

Traditional sand fixation measures have many limitations. For example, engineering sand fixation measures using barriers cannot completely stabilize sand dunes. Biological sand fixation measures utilizing planted vegetation are very difficult to build during the early stages of desertification control. Chemical sand fixation measures spray chemically bonded materials on sand dunes to form a consolidated layer to prevent sand flow, but the cost of the materials used is relatively high. Therefore, new sand fixation technologies and methods urgently need to be developed. This study demonstrates a new sand fixation method, which uses palm mat geotextiles to stabilize sand dunes and to plant grass. We investigated the physical properties of these palm mat geotextiles in the laboratory and observed vegetation growth in the Hobq Desert. The results showed the following: (1) Palm mat geotextiles are lighter and tougher than common straw mat geotextiles. The average weight, thickness, and tensile strength of palm mat geotextiles are 2023 g/m2, 20.14 mm, and 842–860 kPa, respectively. After a year of field observations, the tensile strength decreased by only 2%. (2) Palm mat geotextiles have excellent water retention capacity and scouring resistance; the maximum water content reached 227%, and the substrate lost 2.9% after laboratory simulation of heavy rainfall for three hours with a rainfall intensity of 30 mm h−1. (3) Palm mat geotextiles significantly decreased the soil temperature and increased moisture in summer. The results showed that the palm mat geotextiles had the largest influence on soil temperature in the upper 5 cm of soil and the largest influence on soil moisture in the upper 10 cm of soil. (4) The field experimental results showed that, by the end of the experiment, the vegetation coverage and the biomass of the palm mat geotextiles with dimensions of 2 × 2 m were 3.9 times and 4.1 times that of the control group and 1.7 times and 1.8 times that of the group of high-banded Salix psammophila sand barriers, which are widely used in the Hobq Desert at present. Palm mat geotextiles are a promising material for sand fixation in the Hobq Desert