3.2 Threatening safety
The constructive and productive engineering requires the excavation and backfill of earth and stone, which generates abandoned earth and slag, disturbs the surface vegetation, triggers water and soil loss, and brings a certain impact on the local ecological environment. Because soil and water conservation projects are ancillary projects, its construction quality being good or bad will not have a subversive effect on the product profit. Therefore, some design units and construction units have the same idea that the principal part of the project can spend as much as possible, and the water and soil conservation project should spend as little as possible. The low investment cost of soil and water conservation led to the low standards and quality of engineering, in turn, threatening the safety of the principal parts of the projects. As shown in Figure 3c, photovoltaic panels are vulnerable to damage when the wind blows away the soil around their supports. On the other hand, during the construction process, due to a lack of awareness of soil protection, large-scale site leveling in the construction area destroyed the vegetation, providing a favorable environment for soil erosion. After the completion of construction, no timely soil and water conservation measures – vegetation restoration – resulted in serious soil erosion and threatened the safety of the principal part of the project. For productive and constructive engineering, the production road is extremely important, which is built to ensure that vehicles, personnel, and materials can be timely transported to the construction site. As shown in Figure 4a, although the production road was paved with sand and drainage ditches were designed on both sides of the road, it was destroyed by water erosion during the construction of wind power projects due to low-quality protection. No protection measures had been implemented for the slope after which was cut very steeply, resulting in serious water erosion and destroying the drainage ditches beneath the slope (Figure 4b). Besides, due to neglect of soil and water conservation and lack of awareness of soil protection, the foundation soil was seriously eroded and lost, thus undermining the stability of the foundation and threatening the safety of the transmission tower (Figure 4c), the wind-driven generator and transformer room (Figure 4d). Especially as soil erosion progresses, it will cause the electrical tower to collapse and wire to break or even to fire. Besides, neglect of soil and water conservation in the construction areas may also cause casualties and tremendous damage. Especially the excavation and backfill in the process of productive and constructive projects may cause emergent and dangerous events, such as collapse, landslide, and debris flow. For example, a catastrophic landslide occurred at Hongao dumpsite on Dec 20, 2015, in Shenzhen, Guangdong, Southeast China. The landslide caused 69 causalities with 8 missings, damaged 33 buildings and caused near 800 million RMB economic loss (Xu et al., 2016), related soil and water conservation engineers were arrested. For the safe operation of the principal part of the project, the implementation of soil and water conservation projects is essential for constructive and productive engineering.