Two thirds of Cambodia is occupied by the Cambodian Basin, which is 5 to 30 m above sea level and in the western center of which is Lake Tonle Sap. Mountains and plateaus adjoin the basin on three sides. Southwest of the Tonle Saps, mainly in the provinces of Koh Kong and Pursat, are the Cardamom Mountains, with the highest mountain Phnom Aural (1813 meters). The elephant mountains run along the narrow coastal plain (the highest point is Bokor near Kampot at almost 1000 meters). The Dongrek Mountains are located on the northern border with Thailand. It drops steeply to the south and does not rise above 756 m. The eastern Chlong plateau (up to 942 m) and a strip of mountainous land in the northeast that rises to 1,500 m form the foothills of the Annamite Cordillera.
In the middle of the Cambodian basin is the Tonle Sap lake, which is connected to the Mekong by the river of the same name. During the rainy season from late May to mid-November, the Mekong floods so much (due to the melting snow in the Himalayas) that the water is pushed up the Tonle Sap River against its direction of flow and feeds the lake, which extends from 2,500 km² up to 20,000 km² swells. This makes it the largest lake in Southeast Asia. The Mekong, the largest river in Southeast Asia, flows through Cambodia in a north-south direction for 500 kilometers. It is mostly over 1.6 kilometers wide. At Phnom Penh, the Upper Mekong splits into the Tonle Sap, the Bassac and the Lower Mekong.
According to Commit4fitness.com, Cambodia has practically four seasons: (1) dry and hot from March to May, (2) humid and hot from June to September, (3) humid and less hot from October to November and (4) dry and warm from December to February. In general, the monsoon climate in Cambodia has consistently high temperatures. In December they drop on average to a low of 26 °C and reach their maximum of 30 °C in April.
Cambodia is practically windless except for a few days in December. Then it can get very cold at night, in some regions the thermometer falls well below 10 degrees.
The rainfall is determined by the monsoons; from May to September / October the humid southwest monsoon blows and brings rain, in the rest of the year northeast winds bring dry continental air. The lowest rainfall is measured on the Tonle Sap with an average of 1,000 mm per year; in the rest of the lowlands they are 1,300-2,000 mm annually. On the western slopes of the mountains the rainfall increases to 4,000 mm and more, the maximum values are reached in the Elephant Mountains with 5,300 mm.
Flora and fauna
Despite significant interventions in natural areas, Cambodia’s flora and fauna are still considered diverse. Around 30% of the area of Cambodia is forested, and the trend is falling. An evergreen mountain forest grows at heights of over 700 m with a damp, cool climate, the trees of which can reach heights of up to 60 meters. The vegetation on the western slopes of the mountains, which is rich in precipitation, is characterized by tropical rainforest that is 40 to 50 meters high.
In the undergrowth there are lower plants such as smaller trees, bushes or palms. The lowlands, when not used for agriculture, are covered by monsoons and dry forests, which lose their foliage in the dry season. In regions dominated by flood forests and swampy savannahs, the soils are poor in nutrients and arid. Mangrove forests can be found on the coast.
The fauna is very diverse, despite the lively illegal trade in rare species; A total of 600 protected animal species live in Cambodia. The northeastern provinces in particular still have large wild populations. For example, Indian elephants, tigers, leopards, fruit bats, various bear species and numerous poisonous snakes live in the sparsely populated forest and mountain areas.
The Tonle Sap is rich in water birds and aquatic animals; around 1200 species of fish are known throughout Cambodia. However, the yields from fishing are declining, as human interference is increasingly disrupting the ecological balance of Cambodian waters. In the lower section of the Mekong (Kratie Province) are the last refuge areas of the Irrawaddy dolphin, which is still threatened with extinction there, not least due to dam projects on the upper reaches of the Mekong.
Cambodia’s mineral resources have so far hardly been developed and seem to be quantitatively rather limited. After oil and gas were discovered in the Gulf of Thailand in 2003, oil production – initially 8,000 barrels per day – is to begin in 2020. Mining activities currently relate primarily to the mining of iron ores and bauxite. It is considered certain that Cambodia has manganese, phosphate is also said to be in a degradable form, as well as titanium, gold and silver in small quantities. In addition, precious stones, especially rubies, sapphires and zircons, have been mined since the end of the 19th century.