All deserts are rain deficit, but are formed due to different reasons. Discuss. Also, analyse various adaptations in the flora and fauna to survive the water deficit conditions.

Deserts are the areas of land that receive very low rainfall (less than 25cms) and have very minimal vegetation and biodiversity. Although all deserts are rain deficits they are formed due to different reasons:- i Effect of continentality: Some areas fall outside the areas of rainfall due to their distance from the coast. (e.g., Gobi desert) ii Effect of cold currents: There are cold desiccating effect on the oncoming rainfall seas which reduces moisture in the cold wind. (e.g., Atacama desert) iii Sub-topical high pressure belts: These reduces the formation of clouds due to high pressure in the region. (e.g., Sahara desert) iv Rain- shadow effect of mountains: The desert due to Aravalli range.

v Sub-tropical high pressure belts: These reduces the formation of clouds due to high pressure in the region. (e.g., Sahara desert) vi Rain- shadow effect of mountains: The desert due to Aravalli range. Various adaptations in the flora and fauna to survive the water deficit conditions: i Deep roots unfold in gathering moisture. ii Thick and waxy leaves which reduces the loss of water due to transpiration iii Succulent leaves to store water. iv Nocturnal animals to reduce the effect of heat in daytime v Ability to convert fat into water.

vi Thick urine - to minimize water loss Desertification has increased due to anthropogenic factors leading to increased area under deserts. Activities such as rapid rainwater harvesting, afforestation, agro-ecological farming can help in halting it