Analysis of a 27‐year rainfall data (1977–2003) in the Sultanate of Oman

Abstract

Analysis of variation of rainfall in space, time and amounts, and its attendant effect on the ecosystem is vital in arid and semi-arid environments where the resource is scare, highly variable and unpredictable. In this study, we analyse the characteristics of rainfall in the Sultanate of Oman using data recorded between 1977 and 2003. The data is divided into six geomorphic compartments to represent the various topographic regions in Oman. The average yearly rainfall varies from a low of 76.9 mm in the interior region to a high of 181.9 mm in the Dhofar Mountains, with an average of 117.4 mm for the whole country. Mann-Kendall statistics show a negative but insignificant rainfall trends for the datasets. In northern Oman, the main rainfall season occurs between December and April and that accounts for 57.8-82.9% of the annual rainfall. February and March record the highest rainfall accounting for 35.3 to 42% of the yearly rainfall. The Dhofar Mountains and surrounding areas in southern Oman are dominated by the khareef season in July-August, which produces 44.3 to 67.5% of the rainfall in that area. The number of days of light rainfall (<10 mm per day) is the most dominant and accounts for 66-95% of the rain. Rain in excess of 50 mm per day is rare in Oman (0.4 and 2.9%), but when it does occur can result in serious consequences such as flash flooding, human catastrophes and land degradation. Rainfall records indicate that Muscat and surrounding areas are susceptible to tropical cyclones and catastrophic rainfall (>100 mm rainfall per day) approximately every 50 years.

Projection of Future Changes in Rainfall and Temperature Patterns in Oman

“…The historical temperature profile in Oman due to these air masses is described below based on the 1961-1990 period (Figure 3). Rainfall is caused by four principal mechanisms-convection, cold frontal troughs, monsoons, and tropical storms/cyclones-and their interactions with local topography and other meteorological conditions [11,12]. Historical rainfall patterns in Oman are described below based on the 1960-1990 period (Figure 4).…”

“…There have been relatively few and scattered studies published in the literature about the climate of Oman. Kwarteng [11] scrutinized the statistical variability of rainfall in Oman using selected dataset derived from the Ministry of Regional Municipalities and water resources network. Charabi [12] analyzed the rainfall variability that affected the southern part of Oman during the summer season and its global teleconexion to El Nino Southern Oscillation (ENSO), and the Indian Ocean Dipole (IOD).…”

Projected Changes of Precipitation IDF Curves for Short Duration under Climate Change in Central Vietnam

“…In recent decades, studies in dealing with precipitation events and its trends have enormously progressed [3][4][5][6]. On a regional scale, the precipitation trend has decreased in Asia [7,8].…”

A multi-proxy analysis of the Holocene humid phase from the United Arab Emirates and its implications for southeast Arabia's Neolithic populations

“…This variability is evident throughout the Peninsula today, largely as a consequence of changes in elevation, with higher precipitation in the mountainous terrain which runs along the eastern (al-Hajar Mountains, Oman), southern (Dhofar Mountains, Oman, and the Hadramawt Plateau, Yemen), and western (Yemeni Highlands) fringes of the Peninsula (Glennie and Singhvi, 2002). In addition, significant rainfall events, resulting in flash-flooding, have been recorded throughout parts of the UAE and Oman (Membury, 1997;Kwarteng et al, 2009). …”