Geography – Topography – Drainage of Cambodia
Cambodia is a country in Southeastern Asia, bordering the Gulf of Thailand, between Thailand, Vietnam, and Laos. Its approximate geographical coordinates are 11 ° N 104 ° E. Its 2,572 km border is split among Vietnam (1,228 km), Thailand (803 km) and Laos (541 km), and 443 km from the coastline. Cambodia covers 181,040 square kilometers in the southwestern part of the Indochina peninsula. It lies entirely within the tropics; its southernmost points are only slightly more than 10 ° above the equator. Roughly square in shape, on the east and south by Vietnam, and on the west by the Gulf of Thailand and by Thailand. Much of the country’s area consists of rolling plains. Dominant features are great, almost centrally located, the Tonle Sap and the Mekong River, which traverses the country from north to south, and is the 12th longest river in the world.
Topography in Cambodia
Cambodia falls within several well-defined geographic regions. The biggest part of the country, about 75 percent, consists of the Tonle Sap Basin and the Mekong Lowlands. To the southeast of this great basin is the Mekong Delta, which extends through Vietnam to the South China Sea. The basin and delta regions are rimmed with mountain ranges to the southwest by the Cardamom Mountains and the Elephant Range and the Dangrek Mountains. Higher land to the northeast and to the east, merge into the Central Highlands of southern Vietnam.
The Tonle Sap Basin-Mekong Lowlands region is composed mainly of plains with elevations generally less than 100 meters. As the elevation increases, the terrain becomes more rolling and dissected.
The Cardamom Mountains in the southwest, oriented in a northwest-southeast direction, to rise to more than 1,500 meters. The highest mountain of Cambodia – Phnom Aural, at 1,771 meters, is the eastern part of this range. The Elephant Range, an extension to the south and the southeast from the Cardamom Mountains, rises to elevations of between 500 and 1,000 meters. These two ranges are bordered on the west by a narrow coastal plain that covers Kampong Saom Bay, which faces the Gulf of Thailand. This area was largely isolated until the opening of the port of Kampong Saom (formerly called Sihanoukville), and Kampong Saom, Kampot, Takev, and Phnom Penh in the 1960s.
The Dangrek Mountains at the northern rim of the Tonle Sap Basin consists of a steep escarpment of about 500 meters, the highest point of which reach more than 700 meters. The escarpment faces southward and is the southern edge of the Korat Plateau in Thailand. The watershed along the escarpment marks the border between Thailand and Cambodia. The main road through a pass in the Dangrek Mountains at O Smach connects northwestern Cambodia with Thailand. Despite this road and those running through a few other passes, the escarpment impedes easy communication between the two countries. Between the western part of the Dangrek and the northern part of the Cardamom ranges, however, lies an extension of the Tonle Sap Basin that merges into lowlands in Thailand, which allows easy access from the border to Bangkok.
The Mekong Valley, which offers a communication route between Cambodia and Laos, separates the eastern end of the Dangrek Mountains and the northeastern highlands. To the southeast, the basin joins the Mekong Delta, which extends into Vietnam, providing both water and land relations between the two countries.
Drainage of Cambodia
Except for the small rivers in the southeast of Cambodia. The Cardamom Mountains and Elephant Range from a separate drainage divide. To the east of the river, flowing into the Gulf of Thailand. Toward the southern end of the Elephant Mountains, however, because of the topography, some small rivers flow southward on the eastern side of the divide.
The Mekong River in Cambodia flows southward from the Cambodia-Laos border to a point below Kracheh city, where it turns west for about 50 miles and then turns southwest to Phnom Penh. Extensive rapids run above Kracheh city. From Campong Cham the gradient slopes are very gently, and inundation of areas along the river. At Phnom Penh, four major water courses meet at Fourth Faces. The Mekong River flows from the north to the northeast. They divide into two parallel channels, the Mekong River proper and the Basak River, and flow independently across the delta areas of Cambodia and Vietnam to the South China Sea.
The flow of water in the Tonle Sap is seasonal. In September or in October, the stream of the Mekong River, fed by monsoon rains, is a delta cannot handle the enormous volume of water. At this point, the water pushes northward up the Tonle Sab and empties into the Tonle Sap, so thereby increasing the size of the lake from about 2,590 square kilometers to about 24,605 square kilometers at the height of the flooding. After the Mekong’s water crest-when its downstream channels can handle the water, the river flows out of the engorged lake.
As the level of the Tonle Sap retreats, it deposits a new layer of sediment. The annual flooding, combined with the poor drainage, is surrounded by the surrounding area. The sediment deposited into the lake during the Mekong’s flood stage. Gradual silting of the lake would seem to be occurring; During low water level, it is only about 1.5 meters deep, while the flood stage is between 10 and 15 meters deep.