RELIEF FEATURES OF MIZORAM

The physical set up of Mizoram is composed predominantly of mountainous terrain of tertiary rocks. The mountain ranges are inclined north to south direction in parallel series. The ranges are separated from one another by narrow deep river valleys. The elevation ranges from 21 meters at Tlabung to 2,157 meters at Phawngpui. There are only few and small patches of flat lands, which are mostly intermontane plains.

The terrain of Mizoram is young and immature, it shows prominent relief features with steep slopes, and is still undergoing denudation in response to various exogenetic (isostatic gravity) processes. Since the terrain is young, the geomorphic features of the state do not show much diversity in the formation of landforms. But one distinct features observed in Mizoram is that the western slope of the mountain ranges all have a higher degree of slopes. The most dominant process in evolution of these forms is the action of running water, and is operating from upper tertiary period onwards, till today.

Based upon relief, drainage, lithologic and structural set up, the landforms of Mizoram can broadly be classified into the following:

Mountainous Terrain Province

The eastern half of the state can be classified as Mountainous Terrain Province. The overall relief in this province is higher and the slopes are much more steeper than in the western half. The altitude here scale from 400-2,157 meters. The high points are generally over 1,000 meters. Average elevation in this province is in the order of 1,000 meters. The slopes are very steep, and elevation difference between ridge top and valley varies between 200-600 meters. The ranges are aligned mostly in north-south direction. The important mountain ranges in Mizoram can be briefly described as follows:-

In the north east corner, bordering Manipur and Myanmar runs the Sialkal Range. The highest peak of this range is called Lengteng, which stood at 2,147 meters above sea level. The other high peaks are Naunuarzo and Sur with the height of 2,141 meters and 2,018 meters repectively. In the middle east of Aizawl district there are Chalfilh Range and Tawi range with the elevation of 1,905 meters and 1,889 meters respectively.

The other conspicuous ranges are Mawmrang, located in the midst of Chalfilh and Sialkal range in Aizawl district, Hmuifang range in the central part of the region, and Reiek range in the west of Aizawl mountain. Phawngpui (also known as Blue Mountian) with an altitude of 2,157 meters in the eastern part of Lawngtlai district is the highest peak in Mizoram.

The drainage flows either towards north or south, due to over all structural and lithologic control on the drainage. Large scale structural control is evident. Due to relief and moderately heavy precipitation, the dissection is very high. The width of the valleys increase towards both ends on the north and south.

                                                                           

Ridge and Valley Province

The western part of Mizoram depicts characteristic ridge and valley type of topography. Nearly half of the area of the state is covered by this province. The relief in this province varies between 20-700 meters, and the average elevation is 450 meters. The relief is low in the western part and rises higher towards the east. The hill trend is approximately NNW-SSE to NNE-SSW direction, higher in the central part and tapering towards north and south. The slopes are generally steep on the western side of the ridge; and elevation difference between valley floor and hill top is in the order of 100-200 meters. Yet, a conspicuous mountain ranges are observed in this province. They are Mamit Range and Hachhek Range in the western part of the state.

The Flat Lands

Although the flat lands cannot be grouped as occupying a definite province, we shall try to described them as there are few patches of flat lands scattered at places in Mizoram. They are mostly intermont valley plains in the midst of hills and narrow valleys. These plains are believed to have been formed in the beds of silted up lakes as they are covered by rich alluvial soils.

The largest plain in Mizoram is located at Champhai, about 195 kilometers east of Aizawl town, Champhai plain, bordering Myanmar in the east has a length of only 11.27 kilometers and the widest part is 4.83 kilometers across. The whole area of this plain had been converted into permanent rice cultivation.

The second largest plain is Tuiphai situated at North Vanlaiphai in the south eastern corner of Serchhip district. Thenzawl is another important plain in the Serchhip district which is also under permanent wet rice cultivation. Champhai and Buhchangphai are another patches of flat valleys in the extreme north of Mizoram along the rivers Serlui and Teirei. Mention also may be made to numerous small flat patches like Tuisenhnar near Khawzawl in the east, Zawlpui by the side of Mat river, Phaisen and Chhimluang, west of Bilkhawthlir village in the north, Hortoki and Bairabi etc. along the river Tlawng.

There is a vast area called Chamdur in the western part of saiha district, which at present is thickly vegetated.