## 1 Introduction  
In last few decades, China has embarked on an engineering boom in the transport, water, and mining sectors. However, this construction has had detrimental effects on soil structure and the ecological environment, resulting in numerous exposed slopes and an increased risk of geological disasters such as landslides and debris flows [1]. In order to restore damaged slope structures and the natural ecological environment, slope vegetation restoration technologies such as artificial grass planting and concrete vegetation slope protection are relatively mature [2, 3, 4]. The roots of the plants strengthen the slope in terms of structure and soil water reduction [5]. However, blindly applying vegetation restoration technology may worsen soil water depletion in certain areas, resulting in ecosystem degradation and more severe geological disasters [6]. Conducting a quantitative analysis of soil water dissipation from vegetated slopes is essential for optimizing slope ecological restoration measures and providing a scientific basis for slope ecological restoration. Therefore, studying the soil water dissipation of vegetated slopes holds great significance in the field of environmental geotechnics. Water exchange between the atmosphere and the soil occurs continuously on vegetated slopes. The main form of soil water exchange is evapotranspiration [7]. Slope instability can occur due to changes in soil properties resulting from water exchange. Some scientists have conducted research to explore the relationship between plants and soil water dissipation. The study by [PERSON] et al. [8] reveals that plant transpiration is the largest component of soil water dissipation. [PERSON] and [PERSON] [9] and [PERSON] et al. [10] have concluded that plant transpiration and root water uptake are influenced not only by climatic conditions such as light, temperature, and humidity, but also by the structure and depth of plant roots. [PERSON] et al. [11] found that various factors including vegetation cover, height, leaf area, shallow root distribution, and slope ratio significantly affect soil water. Research by [PERSON] et al. [12] not only demonstrates that vegetation helps reduce soil water loss, but that the litter produced by vegetation also aids in conserving soil water. [PERSON] et al. [13] discovered that water uptake and transpiration by plant roots not only provide energy for plant growth, but also promote the evaporation of slope water, altering soil suction and reducing soil bulk density. Hence, there exists a close relationship between soil water and vegetation. Soil water dissipation is a topic that has been extensively explored by researchers in terms of its correlation with meteorological and environmental factors. [PERSON] et al. [14] discovered that soil water dissipation occurs as a result of interactions with plants, as well as environmental and meteorological factors. This process involves the self-regulation of soil water through potential energy and plant roots after infiltration. Alongside meteorological factors, [PERSON] et al. [15] also examined the influence of different terrain and slope ratios on soil water dissipation in terraces. [PERSON] et al. [16] carried out a study on plantations in the Yangtze River Delta region and observed that soil water loss was associated with atmospheric temperature, humidity, rainfall, barometric pressure, and wind speed. Moreover, the influence of meteorological factors on soil water exhibits variations across diverse regions. Although significant progress has been made in understanding the influence of soil water dissipation, current research primarily focuses on agricultural and forestry fields and forests. However, the impact of different terrain and vegetation conditions on soil water dissipation is not the same. Hence, it is imperative to investigate the soil water dissipation of slopes in the field of environmental geotechnical engineering. This paper conducted a long-term dynamic monitoring test to study the natural evaporation of a large-scale slope model.