Traditional oasis systems in northern Oman are undergoing significant transformation. This dissertation aims to estimate and characterize the number of oases in the region based on topographic, hydrologic, and geologic settings. Using Landsat ETM+ images, the Normalized Difference Vegetation Index (NDVI) was calculated to determine the number of oases. The best elevation model of northern Oman was enhanced by filling gaps with data from Russian military maps. This improved model, along with geological survey data, allowed for the classification of oases into six types: Plain, Foothill, Mountain, Urban, Kawr, and Drainage Oases. Given the arid conditions, the stability of water supply was assessed in six selected oases in the Oman Mountains through spring flow measurements and geological storage analysis. Results indicated that foothill oases generally have a more stable water supply compared to mountain oases. Further studies focused on high agricultural oases in Al Jabal al Akhdar, where farmers cultivate temperate and cool subtropical fruit trees at altitudes up to 2000 m. Analysis of climatic conditions revealed a sharp decline in chilling hours over the past two decades, threatening traditional cropping systems. Additionally, land use changes over the last 27 years have altered water demand patterns, with increased perennial crop cultivation making some oases more vulnerable to drought.
