Abstarct: Abstract Iran has always been affected by varied natural disasters. Among them, flood is ranked first and it is one of the most hazardous natural disasters. Studies of the intensity and frequency of floods, indicates that despite the decrease in rainfall statistics during recent decades, the floods occurrence rate is still increasing. Various factors are effective in the severity and amount of casualties, among which it can be pointed out that the expansion of urbanization and the excessive human intervention on the environment and the increase of man-made changes. The results of these changes in the watersheds affected by urbanization appear in the form of an increase in impervious surfaces that one of the consequences of which is the increase in the formation of the runoff threshold and the occurrence of floods. Therefore, it is necessary to investigate the change in the runoff characteristics through the examination of land use change pattern, in order to understand the effects of land use and cover change (LUCC) on the hydrological processes of the land surface. The present study aimed first to develop land use change maps in Aqqla Watershed in 1989 and 2023, and then to evaluate its impact on the area's flood proneness using Remote Sensing (RS), Geographical Information System (GIS). Runoff was predicted from precipitation, land use, and hydrological soil groups, using the SCS-CN model (the “curve number” approach). Results showed that during the 34 years, a large part of the forests and agricultural lands have been destroyed and turned into urban areas and the coverage of other areas has become weaker. The highest percentage of decrease occurred in agricultural lands and forests which is about 52% and 19%, respectively. The highest average runoffs were obtained 899mm for 1989 and 909mm for 2023. In other words, the runoff height increased by 10mm during 1989-2023. Also, the runoff coefficient was increased by 2%. Accordingly, the land use and runoff changes maps were compared and conformed and analysed. It was observed that the spatial changes of runoff production are completely consistent with the spatial changes of land use changes in the watershed. Obviously, climatic and physical elements like heavy rains, the extent and the size of the watershed are also responsible for causing floods in this region, but anthropocentric activities like degradation of forest and rangelands, incorrect animal husbandry, mismanagement of natural resource, irrational allocation of land to settlements and construction of unsuitable structures and facilities multiplies the impacts and severity of floods.