Rainfall Analysis for the Northern Wadis of United Arab Emirates: A Case Study

The rainfall distribution in space and time, its consistency, probability of occurrences, and drought conditions in three selected wadis in the northern area of the United Arab Emirates (UAE) have been investigated. Like other arid and semi-arid regions, rainfall in the selected wadis is limited, scattered, and random. The standard deviation and coefficient of asymmetry of the rainfall patterns are relatively high. The three wadis have similar rainfall patterns based on the monthly, annual, and 24-h maximum rainfalls. Empirical equations were developed to estimate the annual and 24-h maximum rainfalls. A probability analysis is carried out for the annual and 24-h maximum rainfalls and probability graphs are developed with a confidence level of 95%. Intensity-duration-frequency curves are developed for the three wadis. A conceptual model is used in drought characterization. The available rainfall data of the three wadis are analyzed for drought intensity, duration, and frequency. Based on the drought characterization, the study region is classified as arid. The present study constitutes the first comprehensive analysis for rainfall in UAE.