Rivers and Lakes in Malaysia

                                  

The map above shows the river and lakes in Malaysia. The rivers in Malaysia always have a constant volume of water because of heavy rainfall throughout the year.

Among the important rivers in Malaysia are:

• Rajang River (563 km) and also the longest river in Malaysia
• Pahang River (475km) which is the longest river in the peninsular Malaysia
• Kinabatangan River (560km) longest river in Sabah

The lakes in Malaysia can be categorized into 2.

1. Naturally formed lakes, Examples : Lake Bera and Lake Chini
2. Man-made lakes, Examples : Lake Chenderoh, Lake Temengor and Lake Chini

These waters are the treasures of Malaysia as they are very important as:

• Early civilization sites and have great historical values
• International border such as the Golok River which lies between Malaysia and Thailand
• Border between states such as Bernam river which lies between the state of Perak and the state of Selangor
• Hydroelectric power generation such as the Temengor Dam in Perak River
• Water system for irrigation such as the paddy field under the project "Pengairan Muda" which supply water to the agriculture activities in the Kedah plains.

Irrigation Plans and Hydroelectric Stations

• Water Supply for everyday activities, mining activities and industry such as the Perak River.
• A source of freshwater fish such as the Tilapia fish
• Recreation area such as the waterfalls in Kota Tinggi, Johor
• Road, paths and transport system like Rajang River which can be used to travel between towns in Sarawak and the Kinabatangan river is used to sweep logs from the rural areas  to the factories at the estuary

Malaysian Geography and Climate

Malaysia 

The picture above shows the waters surrounding Malaysia.
There are the South China Sea, the Sulu Sea and the Straits of Malacca.
As we all know Malaysia consists of two regions; the east and the west.
Sarawak and Sabah on the east in Borneo Island and peninsular Malaysia that lies in between Singapore and Thailand.
These two regions are separated by the South China Sea.


Malaysia is a country rich with water resources. Malaysian's climate is affected by the northeast and southwest monsoons. The northeast monsoon blows from October to March, and is responsible for the heavy rains which hit the east coast of the peninsula. It also causes the wettest season in Sabah and Sarawak. The southwest monsoon period occurs between May and September, and is a drier period for the whole country. The period between the two monsoons are marked by heavy rainfall. 


The mean annual rainfall is 3,000 millimetres (mm) .Different places have different mean rainfall and temperature mainly due to relief e.g. the Cameron Highlands have a mean temperature of 18°C and an annual rainfall of over 2,500 mm, compared to Kuala Lumpur's 27°C and 2,400 mm. In general, Sabah and Sarawak experience more rainfall (3,000-4,000 mm) than the peninsula. The humidity is high (80 percent) due to the high evaporation rate. 

Malaysian Drainage Patterns

Dendritic drainage system - They develop where the river channel follows the slope of the terrain. In a dendritic system, there are many contributing streams (analogous to the twigs of a tree), which are then joined together into the tributaries of the main river (the branches and the trunk of the tree, respectively) Examples: Rajang River, Pahang River, Baram River, Kelantan River.

Trellis drainage system- formed in river basins with hard rock and soft rock arranged alternately. The tributaries enter the main river at approximately 90 degree angles, causing a trellis-like appearance of the drainage system. Examples: Perak River

Radial drainage system-   In a radial drainage system the streams radiate outwards from a central high point. Examples: Mount Benom

Parallel drainage system- A parallel drainage system is a pattern of rivers caused by steep slopes with some relief. Because of the steep slopes, the streams are swift and straight, with very few tributaries, and all flow in the same direction. Examples: Kinabatangan River

 River Long Profile & Cross Stream Profile

River long profile refers to the river flow from it's source to it's mouth. On the other hand, cross stream profile refers to the condition of the river valley along the river from upstream to downstream.

Generally, a river can be categorized into 3 stages, the upper level, the middle level and the downstream level.

The upper stage which is also known as the upper level. The river flow is very fast. Waterfalls and cascades can be found here

2nd stage also known as the middle level. The river flow is moderate. River bends, river edges and hill spurs can be found here.

The final stage is known as the downstream level. The river flow is slow. Sediment plains, horseshoe lakes and delta can be found here.