Assessment of Hydrological Extremes for Arid Catchments: A Case Study in Wadi Al Jizzi, North-West Oman

The objective of this research was to analyse hydrological variability by conducting an intensive analysis extreme events, under dry and wet conditions. Drought conditions were assessed using the Standard Precipitation Index (SPI) Rainfall Anomaly (RAI), while Soil Conservation Service (SCS) method used simulate flooding at four stations. SPI results indicated that amount rainfall within catchment area is near normal, ranging from 64% 75%, with some extremely exceptions which may cause flash floods. RAI also but category obtained largest percentage (ranging 36% 50%) very had lowest 9% 36%). simulated flooding, SCS, tended slightly underestimate observed streamflow, performance showed weaknesses when less than 1 m3/s. Nash–Sutcliffe Efficiency higher closer stations outlet, values 0.92 0.94. Distant floods a lower level efficiency, 0.77 0.81. Given fact extremes (dry conditions) are connected, findings two indices SCS consistent suitable for monitoring drought flood events climate change.