The climate and the Farasan Archipelago topography

The climate in the Farasan Archipelago is characterised by a long hot season (April- October) and a short mild one (November -March). In the long dry period high temperatures are usually dominant. The mean annual temperature is 30c. Furthermore, the mean relative humidity in winter ranges from 70% to 80% and in summer between 65% and 78%. The highest rainfall occurs in April and the precipitation is generally unpredictable in the southern part of Red sea (El-Demerdash, 1996). The population of the Farasan Islands at the time of the study was about 5000, inhabiting Farasan Al-Kabir (four villages), Sajid Island (four villages) and Qummah Island (one village) (Gladstone, 2000). The principal occupation is fishing and herds of goats and camels graze near the villages. Several small areas are cultivated with date palm plantations or sorghum.

The island group includes approximately 70,000ha of land with 605km of coastline; the proposed Marine Protected Area covers 331,000ha. The Archipelago is low lying, ranging from a few metres and reaching a maximum height of 70m above sea level. Within the archipelago, the islands range in size from very small, a few m², to hundreds of kilometers (>10km2). There are seven islands of more than 10km²: Farsan Al-Kabir about 381 km², Sajid 150 km², Ad Dissan 36 km², Zifaf 33 km², Saswah 20 km², Qummah 15 km² and Dumsuk 12 km² (Hall et al., 2010), where many studies have taken place. The first two large islands are connected by a 300m length modern bridge (Cooper and Zazzaro, 2014). The topography of the Farasan islands can be divided into three main categories:

1. The general interior surface format of the islands , about 60% of the surface of the Farasan Islands is a subtropical desert of fossil limestone. The remainder is divided approximately equally among silty sand, salt flats and rocky outcrops between 10 to 70m high (Bruckner et al., 2012).In the Farasan Archipelago, each island has a different habitat to the others. For example, Farasan Al-Kabir contains rocky ravines and low ridges north and east of Farasan town and at the western end of the island. The main ridge is 30-40m high and fissured with gullies and low cliffs. Whereas Sajid Island is largely flat with a higher western end, and the smaller islands of Ad Dissan, Zifaf and Saswa are hilly, the coastline tilted upwards approximately 50m above sea level (Bruckner et al., 2012). Furthermore, large boulders, gravels and small stones are found in the steep runnels of these islands (Al Mutairi and Al Shami, 2014). In Zifaf, the fossil coral is in the form of ridges and folds with a number of Sandflats (Al Farhan et al., 2005). Nearly, half of the Qummah and Domsok islands are rocky and about a third of them are sandy (Bruckner et al., 2012)

2. Wadies and Runnels, there are many of short water runnels within islands . The most important runnels in Farasan Al-Kabir (Wadi AlQasar in the south), Wadi AlShami in the north of island and Wadi Al Hussain flows in the western island where the most fertile farmland. Broad wadis between the elevated ridges are characteristic of the Zifaf Island.

3. The coastal zone, There is considerable variation in the composition of natural beaches in the Farasan islands and can be categorized the beaches into four main types:

• The rocky beach

• The sand beach

• Shallow sandy beach

• Vegetation beach (a lot of plants grows on beach)

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