Spatial-Temporal Modeling of Climate Change Trends Using TN۹۰p and DTR Temperature Indices During the Period of ۲۰۰۵ to ۲۰۲۳: A Case Study of Kermanshah Province

This research aimed to analyze the spatial-temporal trends of climate change in Kermanshah Province during the period of ۲۰۰۵ to ۲۰۲۳, using the temperature indices of Daily Temperature Range (DTR) and Warm Nights (TN۹۰p). Daily minimum and maximum temperature data from ۹ synoptic stations were analyzed using non-parametric statistical methods of Mann-Kendall and Sen's slope. The results showed that the diverse topography of the province, particularly the Zagros Mountains, plays a key role in moderating temperature fluctuations. A significant decrease in DTR was observed in the southern and western highlands (up to -۰.۱۵۷ °C) due to the altitude reduction effect, while an increase was observed in the northern and eastern lowlands (up to ۰.۱۷۸ °C) due to intensified atmospheric fluctuations. The high consistency between the results of the two statistical methods (correlation coefficient of ۰.۸۹) confirmed the reliability of the trend analyses. Furthermore, the increase in the TN۹۰p index at stations such as Islamabad-e Gharb (annual trend of ۰.۲۵ °C) and Sarpol-e Zahab indicated intensified nighttime warming and reduced cold radiation. These changes were associated with global mechanisms such as increased greenhouse gases and local factors such as reduced vegetation cover. The findings revealed significant spatial-temporal heterogeneity in the temperature patterns of the province, which has environmental consequences such as thermal stress in mountain ecosystems and intensified wind erosion in the northern plains.