Go through and highlight important information. What is desertification? Is where land is gradually turned into a desert. It occurs mostly in fragile boards on the fringe of deserts. This can be caused by natural and human factors. It threatens one billion people . Causes of desertification climate Change- Is resulting in drier conditions and unreliable rainfall in some regions e.g. the Sahel on the southern margins of the Sahara. Soil Erosion- where vegetation is destroyed, exposing soil which cracks and breaks up making it vulnerable to erosion by wind and rain. Salinisation- Rapid evaporation of poorly practised irrigation leads to surface salts building-up which kill plants. Overgrazing- population pressure results in the limited vegetation supporting too many animals. Over-cultivation- More people need more food which exhausts the soil turning it to dust. Fuelwood- Population growth increases demand . Trees that are stripped of branches will die Reducing Desetification Water and soil management- irrigation needs to be managed carefully if salinization is to be avoided. Too much irrigation and/or badly drained schemes build-up toxic salts on the surface. Contour traps- embankments build along slopes prevent soil being washed away during heavy rainfall. National Park Status- gives legal protection to areas at risk e.g. national park in the Thar desert. Tree planting- reduces soil erosion because the roots bind the soil together, and the leaves and branches provide shade, grazing for animals and fuelwood e.g. prosopis cineraria in the Thar desert. Magic Stones- Stones are placed as a small wall to trap in water in Burkina Faso. This has helped crop yield increase by 50%. Homework on deserts Go through and highlight important information. Produce a revision card on the outline. Answer the Exam question

Examine the causes of desertification and how it can be reduced 9 marks ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Marks 1-3 Basic sentences about desertification. Does not use very much evidence Marks 4-6 Able to write in a clear form to show both the causes and how it can be reduced Marks 7-9 Able to write in a detailed form using named examples throughout.