## 3 Results and Discussions
### Oil Spill Transport Behavior under Various Influencing Factors
#### 3.2.2 Wind  
The effects of wind on the oil spill behavior of rivers include two factors: wind speed and wind direction. Firstly, to explore the effects of wind speed, the wind direction was fixed as the main wind direction southwest in the basin, three river flow rates were set, 1000 m\({}^{3}\)/s, 3000 m\({}^{3}\)/s, 5000 m\({}^{3}\)/s, and the leakage parameter was fracture leakage-2600 t (0.5 h). Figure 8 shows the curves of **v**, **a**, and **l** as a function of wind speed for three river flows. In (a) and (b), the **v** and **a** both decrease continuously with the increase of wind speed. Under the southwest wind, the oil spill will continuously migrate and diffuse downstream along the upper boundary of the river channel. The higher the wind speed, the faster the oil spill accumulates to the upper boundary of the river bank, and the wind's pulling force makes the river bank more obstructive to the oil spill, thus limiting the migration and diffusion of the oil spill. In (b), the downward trend of **a** is faster at Q = 1000 m\({}^{3}\)/s because the smaller the river flow, the faster the oil spill accumulates upward to the upper boundary, and it also indicates that the smaller the river flow, the greater the effects of wind on the oil spill diffusion behavior. In (c), **l** increases and then decreases with increasing wind speed. The combined effect of water flow, wind, and riverbank obstruction causes the oil spill to extend longitudinally faster in the river channel compared to the no-wind condition, so the length of the oil spill contamination zone is longer. Although under the same flow rate, the larger the wind speed is, the longer the oil spill contamination zone is, the rate of change is related to the migration rate of the oil spill, and **v** decreases to a certain extent, **l** will also be smaller. Exploring the effects of wind direction, the wind speeds were fixed at 2.1 m/s and 5 m/s, the flow rate was 5000 m\({}^{3}\)/s, and the leakage parameter was 2600 t (0.5 h). Figure 9 shows **v**, **a**, and **l** for different wind directions. The modeled river section is oriented northwest to southeast. For the direction of oil spill transport, northwest winds can be defined as downwind; north, west, and southwest winds as partial downwind, and vice versa for headwind and partial headwind. In (a), (b), and (c), it can be seen that the values of **v**, **a**, and **l** are higher than those of the opposite wind direction for the same wind speed in downwind and partial downwind conditions, indicating that the migration, diffusion and longitudinal extension behaviors of oil spills are faster in downwind and partial downwind conditions; The reason that **v**, **a** under downwind and headwind is larger and **l** is smaller compared to partial downwind and partial headwind and does not change much with wind speed is that under downwind and headwind conditions, the oil spill accumulates to a lesser extent on the river bank side and is less obstructed by the river bank, so the oil spill migrates and diffuses faster and extends along the river channel more slowly. Combining the effects of wind speed and wind direction on the oil spill transport behavior under  
Figure 8: Variation of **v**, **a**, and **l** with wind speed. downwind and headwind conditions, the effects of wind speed on the oil spill transport behavior are relatively small; under the rest of the wind directions, the migration and diffusion behaviors of the oil spill will slow down with the increase of wind speed, and the longitudinal extension behaviors of the oil spill will be accelerated firstly and then slowed down with the increase of wind speed. Through the above analysis, it can be seen that the wind will affect the migration speed and transport state of the oil spill.