An assessment of the influence of orography on precipitation patterns in the northern regions of Iran

The phenomenon wherein precipitation increases as altitude ascends is referred to as the precipitation gradient, that significant importance in the field of hydrological forecasting in mountain basins and management of water resources. The present study aims to investigate the changes in the topography of the earth on the formation and movement pattern of precipitation, the average rainfall of the IMERG V06 satellite and the dem of the 0.1 degree elevation of the precipitation gradient for eight main directions or coding in the Python environment of the Alborz Mountains were extracted. Then, in order to determine the movement pattern of precipitation, longitudinal and latitude profiles were used. The study findings indicate that in the northeast region of Golestan province (positive gradient), there exists a positive gradient of precipitation, which amounts to 0. 44 mm.m elevation. Furthermore, it is worth noting that in the southeastern region of Semnan, there exists a negative gradient of 1. 91 mm.m reduction in precipitation of elevation gain. Additionally, it was found that the precipitation gradient was significantly influenced by both the north and south directions, accounting for 16. 8% and 25.4% of the effect, respectively, at a significance level of 0. 01. On the northern slopes, a negative correlation has been observed between the amount of precipitation and latitude, wherein higher latitudes are associated with lower precipitation levels. Conversely, a positive correlation has been noted between the amount of precipitation and latitude in other regions, where higher latitudes correspond to increased levels of precipitation. The intricate nature of precipitation in mountainous regions presents a challenge in establishing a comprehensive pattern due to the multifaceted influence of anthropogenic, climactic, and terrestrial variables, nevertheless, comprehending precipitation patterns in the context of decision-making can benefit water resource management.