The Arabian Peninsula is surrounded by the Persian Gulf to the east, the Red Sea to the west, and the Indian Ocean to the south. It is one of the hottest and driest regions in the world.
The term “Arabia” that is used in the ancient Latin and Greek sources covers a region from the east coast of the River Nile to the Sinai Peninsula in the north and Syria. Today, the term “Arabian Peninsula” refers to a more restricted area and consists of an area of 3.1 million km2 with a coastline of 9,000 km.
The rainfall in this region is approximately less than 150 millimeters, which causes the existence of a desert climate. Arabia resembles a large rectangle stretching between the Asian continent and the African continent. Arabia was separated from India and Iran 130 or 200 million years ago and from Africa 65 million years ago. The west and east coast of the Red Sea, which are like two halves of a cloth torn down the middle, give us fairly important clues about the formation and the course of the process of separation.
In terms of geographical structure and climatic conditions the Arabian Peninsula, called Jaziratu al-Arab by the Arabs, is divided into several regions. Although the number and borders of these regions have been much debated in history, three regions have come to the fore: Yemen, which includes the southwest of the Peninsula, the Hejaz, which is composed of the western regions, and the Najd, which includes the interior and the eastern coast. The Hejaz has been researched to a greater extent by geographers due to the fact that Islam emerged there. Yemen is important as it is the main production and trade center of the Arabian Peninsula.
Throughout history, the peninsula has been negatively influenced by the temperature, especially the great heat in the summer. It is also seriously affected by the seasons and by sudden temperature changes between night and day. The temperature increases as one goes from the north to the south and from the high plateaus to low areas; occasionally this temperature can reach 50°C. The cold of winter makes itself partially felt in the north and along the coasts of the Persian Gulf, yet it is almost never felt along the Red Sea coasts where the temperature rarely falls below 15°C. Although the rain that falls from February to March or from May to September partially reduces the suffocating effect of the hot and arid climate characteristic of the peninsula, nevertheless it can not prevent temperatures reaching 40°C in the daytime and 30°C at night along the coasts. In particular, such high temperatures along with an increase in humidity along the coasts make daily life considerably difficult. However, the same conditions form an appropriate environment for agriculture of high quality within certain regions. For instance, in Yemen, the winter temperature in Tihama, which lies in the southern parts of the Tihama region, located between the mountain ranges along the west coast of the peninsula and the Red Sea, is between 25° and 35°C and the humid fog that stretches over the mountains in the morning enables the growth of valuable agricultural products such as coffee.
The rocky and craggy mountains that cover the western regions of Arabia are intersected by valleys that were formed by floods. Residential areas were established in the surrounding areas of these valleys, which were relatively more productive. However, heavy rains that are short in duration have led to the soil being sandy and not water-retentive. For this reason, most of these residential areas have remained as temporary settlements where nomadic Arabs would come and stay for a time. At the same time, techniques and measures were developed that enabled Yemen to utilize the waters in the valley that lay deep in the ground, and thus these valleys were transformed into areas appropriate for residential areas.
Settlement was most established in the Ahsa regions; this is an Arabic word used for ground which is made up of hard rocks and covered with sand. When it rains, this hard layer plays a role in preventing the waters from reaching the depths and enables the utilization of water by people; this factor plays an important role in the preference of such areas.
The soil and rain traits limit the permanent agriculture areas available on the peninsula. In the southwestern, southern and southeastern parts of the Arabian Peninsula, where the rain falls in the form of summer rains (monsoons), the valleys are filled by sudden and short rain storms in which the water quickly evaporates, due to the hot weather, even before it has reached the lower levels of the soil; thus the river valleys remain mostly arid. Combined with a soil that is extremely permeable and does not retain water, the underground water resources are diminished and thus field agriculture based on natural irrigation is limited only to the southwestern regions. The above-mentioned weather conditions also determine the vegetation of the peninsula, only allowing the growth of such plants as trees, bushes, short bushes and shrubs that have long life spans and which are hardy in the arid climate. The plants which only grow during the rainy season and which have short life spans are also part of the flora of the region. In the Rub’ul-hali, which is the largest and harshest desert in the southeastern area, almost no vegetation that can reach the underground water resources exist. These factors underline the inhospitable natural conditions that pervade throughout the peninsula, all of which are caused by the lack of water resources in area. This is the main reason why there is a gap between the southeastern region, which has fertile and productive soil because of its extensive rainfall and the deserts in the rest of the peninsula, which tend to be infertile. The permanent water resources in parts other than the south of the peninsula consist only of underground water which is sparsely located throughout the valleys. The wells which have been dug in the valley are constantly closed up by sand storms, while the standing water that accumulates after the rain storms in the valleys evaporates quickly.
This difference between the regions, as far as vegetation is concerned, can also be observed in the regional produce. In the inner regions, date trees thrive in the arid climate, and being hardy with little need of water, dominate, whereas Yemen is renowned for the sweet-gum (liquidambar styrax), which is a symbol of productivity and luxury. Dates are the main food source for people in the oases. There are a few areas where wheat, barley, millet, onions, sesame, various vegetables, tobacco, apricots, almonds, grapes and citrus fruits can be grown. In the southern regions it is possible to grow such a variety of crops as bananas, cotton, coffee and even rice and sugar cane.
The harshness of the climate throughout the peninsula also affects the surrounding seas. The climate and structure of both the Red Sea and the Persian Gulf are of a quality that prevents development in the regions adjacent to these seas. These two seas, with their coral reefs, adverse currents and winds make regional maritime activities considerably difficult. The coasts of the Arabian Peninsula make the situation any easier. The coast lines, particularly the southern coast line, are not suitable for the construction of ports. The port cities that are open to the sea do not have a road transportation network or an agricultural hinterland to support the development of trade in these cities or to feed the cities. In this context, the only exception seems to be Aden.
Despite all these negative aspects, the region has accommodated an urban population that makes an income from trade and agriculture as well as a nomadic population involved in animal husbandry. The nomadic Bedouins also made a living by protecting the caravans and guiding them or by attacking these same caravans to loot their goods. Trade, shipping, fishery, and pearl and sponge hunting were relatively important along the coasts.
To sum up, in such a harsh region where the sea, the climate and the geography are all disadvantageous for the region, long-term settlements generally proved to be inappropriate. Over time, places of settlement, such as Jeddah began to form, whereas other cities, such as Djar, a port of Medina, were erased off the map.
It is assumed that during the period when Shuayba was the port of Mecca that it was a small fishing village consisting of cottages at which the trade ships rarely loaded or unloaded. Jeddah became a prestigious port and gained importance only after the Uthman designated it as the port of Mecca in place of Shuayba. During this period the city developed partly because it was the port of Mecca and partly because of its strategic location for the defense of the Hejaz; Jeddah was transformed into a garrison city and its position was fortified. Jeddah not only benefited from the trade of Mecca, which city it served as a port, but it was also the focal point of the Islamic world, turning it into a huge import center where goods coming from Egypt and India arrived. Over time, Jeddah acquired religious, financial and strategic importance, becoming the most active and important port in the Red Sea and the Arabian Peninsula. With its importance in terms of trade activities it managed to become one of the few trade centers during the Middle Ages. Moreover, with time, and particularly when the Crusaders threatened the security on the northern roadways, Jeddah became an important meeting and transition point for pilgrimage groups coming from the Red Sea.
