## 1 Introduction  
A geotextile is a permeable textile made from synthetic fibers through processes such as needle punching or weaving. Due to its excellent performance in reinforcement, filtration, and drainage functions [1, 2, 3], it has become an indispensable material in many major projects, including water conservancy, highways, and environmental protection. Geotextile bags, made from geotextiles, are widely used in coastal and riverbank protection due to their significant deformation coordination ability, low cost, convenient construction, and eco-friendliness [4, 5]. Currently, geotextile bag technology has been applied in coastal and riverbank projects in many countries and regions, including China, Europe, the United States, Canada, Japan, India, Bangladesh, and Australia [6, 7, 8, 9]. A summary of domestic and international research on the application of geotextile bags reveals that the technology is primarily used in road and building foundation reinforcement, retaining wall engineering, and coastal and riverbank erosion protection [10; 11]. However, geotextiles, as polymer materials, inevitably undergo aging during use. Studies have shown [12; 13; 14] that light and temperature are the main factors contributing to geotextile aging. As usage time increases, the material's performance declines, leading to a loss of functionality. The aging performance of geotextile bags directly affects the reliability and safety of revetment projects, making their durability an urgent issue that requires further research [15; 16; 17; 18; 19]. Domestic and foreign scholars have conducted extensive research on the durability of geotextiles. [PERSON] [20] conducted a 450-day aging test on geotextiles covered with 5 cm of sand, and the results showed that the 5 cm sand cover improved the durability of the geotextiles. [PERSON] et al. [21] developed a composite geotextile, and the results indicated that an outer layer with sand-collecting functionality could effectively enhance the durability of the inner geotextile. [PERSON] et al. [22] found that under relatively low ultraviolet (UV) irradiation intensities and outdoor exposure, carboxylic acid carbonyl groups formed on the surface of the samples, showing a strong correlation between the two test methods. However, under high-UV irradiation intensity, ester carbonyl groups and low-molecular-weight acids appeared, and the correlation between the two was poor. [PERSON] et al. [14] conducted aging tests on polypropylene (PP) non-woven geotextiles and found that UV radiation significantly reduced the strength of the geotextiles. Under 35 MJ/m\({}^{2}\) of UV radiation, the performance of ordinary geotextiles declined noticeably, while that of geotextiles with added light stabilizers remained largely unchanged. [PERSON] et al. [23] studied the UV aging performance of PP geotextiles and found that UV radiation affected the fibers, altering both strength and elongation. [PERSON] et al. [24] investigated the aging patterns of polyethylene terephthalate (PET) filament-reinforced PP non-woven geotextiles under different weathering conditions. The results showed that UV radiation was the primary cause of geotextile degradation and the extent of aging was closely related to temperature, UV radiation intensity, and exposure time. [PERSON] et al. [25] used three accelerated aging methods to explore the thermal oxidation performance of PP geotextiles and compare the effectiveness of stabilizers under different aging conditions. They found that stabilizers were more effective under high oxygen pressure and water immersion, indicating that stabilizers could effectively inhibit material aging under specific environmental conditions. [PERSON] et al. [26] studied the relationship between the tensile properties of single-PP-filament geotextiles and temperature, as well as the effect of titanium dioxide (TiO\({}_{2}\)) addition on PP material performance.