GIS-based investigation of precipitation, temperature, thunderstorms, and snow depth parameters in road accidents in Semnan province (case study: Semnan-Shahrood and Mayamey-Jajarm roads)

The effect of weather and climate conditions on road accidents has attracted considerable attention in recent years. This research aimed to analyze climatic parameters, including wind speed, dust storms, fog, and hail, using the GIS technique. Station data used for this study were from Amirieh, Bastam, Foroomad, Qaleh Now-e Kharaqan, Hosseinian, Kohan, Mehdishahr, Majen, and Nardin in Semnan province. Following that, accidents on the main roads of Semnan-Shahrud and Mayamey-Jajarm over six years (2016-2021) were examined. Maps were produced regarding accident risk for each meteorological parameter on the mentioned roads using ArcGIS 10.3 software, divided into five situations: very low, low, medium, high, and very high. A comparison was made between Kriging and IDW as interpolation methods. According to the findings, most accidents happen on both roads in April. Also, on both roads, most accidents happen during the day, followed by lighting at night in all years. The results showed that the most serious accidents occurred on Semnan-Shahrood and Mayamey-Jajarm roads during clear weather conditions between 2016 and 2021. Furthermore, rainy conditions are ranked second regarding the risk of accidents on both roads during the years mentioned. The findings showed that the level of accident risk for the climatic parameters of thunderstorms and temperature was reported as low to medium and very low, respectively, on the Semnan-Shahrood road. Also, the risk level for precipitation and snow depth parameters was assessed as low to moderate. Further, the level of accident risk for the climatic parameters of snow depth, temperature, thunderstorm, and precipitation was evaluated as low to high, low, medium, and low to medium on the Mayamey-Jajarm road.