What are the causes for deserts?

The nine causes are: (1) Natural Situation (2) Air Circulation Pattern (3) Currents: A Hot Water Heating System (4) Oceanic Currents (5) Remote Situation From an Oceanic Moisture (6) Mountain Barrier (7) Rainless (8) Temperature and (9) Man in Desert Making. The world has always had its deserts.

Why are the deserts spreading?

Deserts are expanding – every year they grow by an area around the size of Ireland. But it’s not a natural process; it’s manmade. Overgrazing, increasing agriculture, deforestation and a growing use of water are eroding the land. And it is particularly affecting parts of Africa, America or Asia.

What causes the Sahara desert?

The rise in solar radiation amplified the African monsoon, a seasonal wind shift over the region caused by temperature differences between the land and ocean. The increased heat over the Sahara created a low pressure system that ushered moisture from the Atlantic Ocean into the barren desert.

What are the three main conditions that gives rise to desert climate?

All these climatic, desert-producing factors – descending, drying air currents; mountain-produced rainshadows; distance from oceanic moisture sources; and cold ocean currents – are instrumental, sometimes singly, more often in combination, as primary forces producing arid lands.

What are 3 causes of desertification?

Human activities that contribute to desertification include the expansion and intensive use of agricultural lands, poor irrigation practices, deforestation, and overgrazing. These unsustainable land uses place enormous pressure on the land by altering its soil chemistry and hydrology.

What are the causes of drought and desertification?

Although the cycles of drought and climatic disturbances can contribute to the development of desertification, it is mainly caused by overgrazing, land clearance, over-exploitation of cultivated and natural lands, and by generally using land in a way that is inappropriate to local conditions.

Why do deserts form at high elevations?

High-pressure air forces low-pressure air–usually dry air at higher altitudes–closer to the ground. This heat transfers to the ground, creating high ground temperatures. The Sahara Desert and the Kalahari Desert, both in Africa, formed as a result of low-pressure air heating the ground and evaporating groundwater.

What are the causes of aridity?

The causes of aridity are: (1) Distance 2) Wind System) Rain and (4) Temperature.

What are the causes of desertification?

The regions that are desert have suffered geographically or climatically or both due to their natural situation. Perhaps the most significant natural situation leading to desert formation is a by-product of the movement of air masses over the surface of the earth.

Why do deserts expand?

Deserts also expand as a result of the climatic variations and the margins where deserts meet wetlands often blur in between the different seasons. These changes however occur over a very long period of time and are not very significant when we are considering the issue here.

Should we be worried about the spread of deserts?

While the UN’s warning about the spread of deserts should be taken seriously, its plan to halt desertification is dangerously flawed. Carbon dioxide and methane emissions do not create deserts. Actually, increased levels of greenhouse gases have helped boost green foliage in the world’s arid regions.

How does overgrazing affect the desert?

Overgrazing – an increasing population results in larger desert areas being farmed. Sheep, cattle and goats are overgrazing the vegetation. This leaves the soil exposed to erosion.