The surface area of Yemen is 527,970 km², divided into XXX. The population density is 40 per km². About 2/3 of Yemen's area is uninhabited.
Yemen takes up the souther tip of the Arabian peninsula. The country is defined by the sea, the mountains of Asir, where it meets Saudi Arabia. The border to Oman is more political than cultural, as the regions on both sides of this border are quite seperate from their respective capitals.
Yemen is listed without any perennial rivers or lakes, only wadis that dry out in summer.
Yemen has no permanent rivers. Seasonal rivers, called wadi, cut through the landscape all over and allow some flow of water to keep oases inhabitable.
Borders and Coastlines
1,746 km (Saudi Arabia 1,458 km, Oman 288 km).
Coastline: 1,906 km.
Highest and lowest points
Highest point: Nabi Shu'ayb mountain 3,760 m
Where the montains end, Yemen quickly turns into desert. Yemen shares the Rub al-Khali with Saudi Arabia, the largest expanse of sand in the world.
Arable land: 2.8%
The mountains of Yemen are dominated by jagged peaks. The western highland has fertile soil and sufficient rainfall. The central highlands is more like a plateau mainly with rolling hills. Yemen has the highest mountain in the Arab world, the Nabi Shu'ayn
It's the mountains that makes Yemen habitable. The climate in the Yemeni mountains is the most pleasant on the entire Arabian peninsula, and fertile. Yet, in the lowlands, the climate can meet the extremes, and in the Tihama region one find some of the hottest and most humid climates in the world. Annual maximum temperatures usually pass 50ºC, and humidity can climb to 70%.
The highest mountains of Yemen can have up to 750 mm of annual rainfall. Some regions of the western highlands can have up to 1,500 mm, while coastal Aden has only 125 mm.