Video Lesson

Lesson Objective

At the end of this section, you will be able to:

• Describe major landforms of Ethiopia.

Brainstorming Question

Have you had opportunities to travel to the different regions of Ethiopia? If you have, what did you notice along your routes?

Key terms and concepts

Landforms are distinct features on the Earth’s surface, and in Ethiopia, they have been shaped primarily by tectonic and volcanic activities dating back to the Cenozoic era. The country showcases a remarkable variety of highlands, plateaus, mountains, deep river gorges, and lowlands. Elevations range from 116 meters below sea level at the Dallol Depression to 4,620 meters above sea level at Ras Dashen in the Simien Mountains. With 56% of its land over 1,000 meters above sea level, Ethiopia is often referred to as the “Roof of Eastern Africa.” The extensive Rift Valley, which stretches from Syria to Mozambique, bisects this elevated landscape.

Figure 1.4. Topography of Ethiopia

These landforms result from two opposing forces:

– Endogenic forces: These originate from within the Earth, including volcanic activity and tectonic movements.

– Exogenic forces: These occur at the surface and include processes like denudation and peneplanation.

The interplay between these forces has created the diverse landforms we see in Ethiopia today.

Physiographic Divisions of Ethiopia

Ethiopia’s relief can be categorized into three main physiographic divisions:

1. The Western Highlands and Associated Lowlands

2. The Southeastern Highlands and Associated Lowlands

3. The Rift Valley

I. The Western Highlands and Associated Lowlands

A. The Western Highlands

The Western Highlands extend from Tigray in the north to the Gamo and Goffa highlands in the southwest, covering 44% of Ethiopia’s area. This region is separated from the southeastern highlands by the Rift Valley and serves as a crucial source for major rivers like the Abbay, Baro, and Tekezze, which significantly influence Ethiopia’s geopolitical standing in northeastern Africa and the Middle East.

This region is divided into four main groups based on internal altitudinal variability:

– The Plateau of Tigray

– The North Central Massif

– The Plateau of Shewa

– The Southwestern Highlands

Figure 1.5.: Ethiopian’ Main Topographic Regions

I. The western Highlands and Associated Lowlands

A. The Western Highlands

The Western Highlands of Ethiopia stretch from Tigray in the north to the highlands of Gamo and Goffa in the southwest, covering 44% of the country’s area. They are separated from the southeastern highlands by the Rift Valley and are the largest physiographic region. This region is the source of major rivers such as the Abbay, Baro, and Tekezze, which play a significant role in Ethiopia’s geopolitical influence in northeastern Africa and the Middle East.

The Western Highlands are divided into four main groups based on internal altitudinal variability:

1. The Plateau of Tigray
2. The North Central Massif
3. The Plateau of Shewa
4. The Southwestern Highlands

A. The Plateau of Tigray

The Plateau of Tigray is located in the northernmost part of Ethiopia, bordered by the Mereb River to the north and the Tekezze River to the south. It consists mainly of eroded sandstones and limestones with thin soils. This plateau features high mountains with elevations exceeding 3,000 meters above sea level. Notable peaks include:

• Mount Tsibet – 3988 m a.m.s.l.
• Mount Ambalage – 3291 m a.m.s.l.
• Mount Assimba – 3248 m a.m.s.l.

B. The North Central Massif

The North Central Massif stretches from the Abbay Gorge in the south to the Tekezze Gorge in the north, encompassing highlands such as Gondar, Gojjam, and Wollo. This area is known for its rugged plateaus capped with Tertiary-period basalts surrounded by deep gorges. Key mountain peaks include:

• Mount Ras Dashen – 4620 m a.m.s.l.,
• Mount Guna – 4231 m a.m.s.l.,
• Mount Abuna Yoseph – 4190 m a.m.s.l., and
• Mount Hey – 4154 m a.m.s.l.

C. The Plateau of Shewa (Central Plateau)

The Shewan Plateau is a dome-shaped region that acts as a watershed for several river basins including Awash and Omo-Gibe. It is characterized by its crescent shape which causes rivers like Abbay to curve northward.

d. The Southwestern Highlands

This region experiences heavy rainfall and erosion due to its tropical climate. It includes highlands such as Wollega, Illubabor, Jimma, Kafa, Gamo, and Goffa.

Key features include:

• Gamo-Konso Highlands
• Maji-Korma Highlands
• Dawuro-Konta Highlands

Mount Gughe stands as the highest point at 4,200 m a.m.s.l., located in the Gamo plateau.

II. The Southeastern Highlands and Associated Lowlands

This physiographic region is found to the southeast of the rift valley. This region is further divided into highland and lowland units.

1. The Southeastern Highlands

The Southeastern Highlands of Ethiopia include:

a) the Hararghe plateaus,

b) the Arsi plateau,

c) the Bale Massif, and

d) the Sidama highlands.

Their formation is similar to that of the North and Southwestern Highlands and they are capped by basaltic rock. They are the main sources of the Wabe Shebelle and Genale rivers.

They are bounded:

• in the west, by the fault line of the Rift Valley;
• in the east, by the Ogaden Lowlands; and
• in the south by the Elkerie and Borena Lowlands.
• The Hararghe Plateaus

The Plateau of Hararghe rises sharply from the Rift Valley fault line and extends gently east to Jigjiga. Beyond Jigjiga, the elevation decreases, transitioning into the Ogaden Lowlands. The Plateau is drained by the left-bank tributaries of the Wabe Shebelle River. The erosion of basaltic rocks has exposed underlying limestones and earlier sedimentary rocks. This region is a major producer of coffee, chat, sorghum, and millet.

The prominent mountain peaks include:

• Mount Gara Muletta (3381 m a.m.s.l.), and
• Mount Jebel Tita (3122 m a.m.s.l.).
• The Arsi Plateau

This plateau area consists of the Gugu and Chillalo Massif. It is an extendingly rolling plateau; it is a very suitable plateau for farming. These features has been comparatively low because of the erosion on the Arsi plateau. The Arsi plateau is known for its wheat production.

The highest points on the Arsi plateau are:

• Mount Chillallo (4136 m a.m.s.l.),
• Mount Bada (4139 m a.m.s.l.), and
• Mount Kaka (4180 m a.m.s.l.).
• The Bale Massif

The Bale Massif lies next to the Arsi Plateau, separated by the headstreams of the Wabe Shebelle River. Its northern region features flat terrain similar to basaltic plateaus, while the southern part is marked by large mountains.

The highest points on the Bale Mountains are:

• Mount Tulu Dimtu (4377 m a.m.s.l.), and
• Mount Batu (4307 m a.m.s.l.).
• The Sidama Highlands

The Sidama Highlands, which form the southwest extension of the southeastern highlands, are separated from the Bale Highlands by the Genale River Valley. The plateau gradually slopes to the south and southeast, and is drained by the Genale River and its tributaries.

• The Southeastern Lowlands

These lowlands extend from the foot hills of the southeastern highlands along the Ethio-Somalian and Ethio-Kenyan borders. Their general elevations lie between 500 and 1000 m a.s.l. They consist of:

• the Ogaden plains,
• the Elkeri plains,
• the Borena plains, and
• the Genale plains.

These landforms are highly extensive lowlands. They are characterized by extreme climatic condition with low annual rainfall-often below 500 mm. Most of these lowlands are covered by sandstones and recent marine deposits. The people practice a pastoralist way of life because of the harsh climate.

The Western Lowlands

This region lies southeast of the Rift Valley and includes:

• Hararghe Plateaus
• Arsi Plateau
• Bale Massif
• Sidama Highlands

These highlands are capped by basaltic rock and serve as vital sources for rivers like Wabe Shebelle.

III. The Rift Valley

The Ethiopian Rift Valley System runs from the Afar Depression in the north through various lakes up to Lake Turkana. This area is part of the Great East African Rift Valley and showcases geological instability through active volcanoes and hot springs..

This part of the Ethiopian Rift System is characterized by  

• Faulted depressions (the Dallol Depression) and grabens (also called troughs), and
•  Cinder cones and Volcanic mountains