DESERTIFICATION_ SlideShare
- 1. DESERTIFICATION Presented by Shanza Maryam MSc. Zoology 2nd semester
- 2. CONTENTS: *INTRODUCTION. *DESERTIFICATION. *TYPES OF DESERTIFICATION. *CAUSES OF DESERTIFICATION. *Impacts of desertification *Solution for desertification
- 3. INTRODUCTION • The process by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture. • “nearly one fifth of the world’s land is threatened with desertification “
- 5. Deserts of the World Approximately one-third of the Earth’s land surface is desert, arid land with meager rainfall that supports only sparse vegetation and a limited population of people and animals.
- 6. What is desertification? • Desertification is land degradation process in arid and semi-arid areas. • It is a process by which fertile land is transformed into desert. • It becomes progressively drier Unable to support any plant growth for food production. • It occur due to various factors including climatic variations and human activities.
- 7. Types of desertification 1.Light desertification 2.Moderat desertification 3.Severe desertification 4.Very severe desertification
- 8. 1. Light Desertification: • In this type of desertification, a very slight damage occurs in vegetation cover and soil. • This damage does not affect the biological capacity of the environment and can be neglected.
- 9. 2. Moderate desertification: •A medium degree of damage of vegetation cover occurs and formation of small sand dunes and salinization of the soil which reduces production by 10 25%.
- 10. 3.Severe Desertification: • In this type, spreading of weeds and unwanted shrubs in the pasture as well as increasing of the erosion activity which affects the vegetation cover and reduces production up to 50%.
- 11. 4.Very severe desertification: • In this type of desertification, great sand dunes occurs and formation of many grooves and valleys and the salinization of the soil which leads to soil degradation. •It is the most serious type of desertification.
- 12. Main Causes of desertification > Overgrazing > Drought > Climate change > Over cultivation > Deforestation > Natural disasters.
- 13. 1. OVERGRAZING • Overgrazing is grazing by livestock or wildlife to the point where the grass cover is depleted, leaving bare, unprotected patches of soil.
- 14. • Animal grazing is a huge problem for many areas that are starting to become desert biomes. • If there are too many animals that are overgrazing in certain spots, it makes it difficult for the plants to grow back, which hurts the biome and makes it lose its former green glory.
- 15. • Too many animals grazing on the land. • Animals eat all the vegetation. • Vegetation fails to grow. • Soil is exposed to rain and wind. • Soil is washed or blown away.
- 16. DROUGHT • Drought is the result of a deficiency in precipitation. • A drought is caused by drier than normal conditions that can eventually lead to water supply problems. • Really hot temperatures can make a dought worse by causing moisture to evaporate from the soil.
- 17. • A long period without rainfall . •Causes crops to die. • lack of food. •May have to move to find food.
- 18. Climate Changes Both natural variability in climate and global warming can also affect rainfall patterns around the world, which can contribute to desertification. Rainfall has a cooling effect on the land surface, so a decline in rainfall can allow soils to dry out in the heat and become more prone to erosion
- 19. • Overcultivation • Many crops being grown on the land year after year. • No rotation of crops. • Crops take all the nutrients from the soil. • The soil becomes infertile and nothing can grow. • Because there are no crops to protect the soil the soil is again easily eroded by the wind and rain.
- 20. Deforestation It is cutting down or clearing of trees from a wooded area. If trees are removed, the area can become much warmer and drier, ⚫ which may result in desertification, ⚫ which is a transform fertile land into desert.
- 21. Natural Disasters • •There are some cases where the land gets damaged because of natural disasters, including drought. • In those cases, there isn’t a lot that people can do except work to try and help rehabilitate the land after it has already been damaged by nature.
- 22. Impacts of Desertification > Agricultural production and useable water resources are depleting. > Migration of humans and wildlife from the affected areas is increasing. > Shortage of food. > Soil erosion > Drought > Increase in poverty at local level may occur.
- 23. Desertification in Pakistan >Pakistan is situated in warm and dry climatic region where the annual amount of rainfall is less than 25 cm. >Arid to semi-arid weather conditions previal in almost 80% area of Pakistan. > The main cause of desertification in Pakistan is unsafe and poor ways of cultivation which result in _soil erosion _lapse of fertility _continuous drop in biodiversit
- 24. Solutions for Desertification •Rising awareness of the problem •Planting indigenous trees and shrubs •Developing sustainable agricultural practices •Controlled grazing •Crop rotation (increase fertility & reduce soil erosion)
- 25. •Proper land management •Soil and water management •Introduce proper technologies •Manage dry land resources • Tree planting schemes to reduce soil erosion
- 26. Thank you