1. + Soils and change The causes of soil erosion

2. + Soil erosion The washing away or blowing away of top soil such that the fertility of the remaining soil is greatly reduced. Soil erosion is most rapid in those areas where there is the misuse of land by people.

3. + Definitions in this power point Just so you know: All of the definitions for this power point were taken from: ‘A-Z Handbook: Geography’ 4 th edition. M.Skinner, D.Redfern, G.Farmer. It is a very useful book, one well worth buying.

4. + The causes of soil erosion Erosion by wind and water Physical degradation Chemical degradation Biological degradation Climate and land use change Impact of artificial fetiliisers and pesticides Erosion – the removal of weathered material by the action of gravity, water, wind or ice. Weathering – the disintegration and decomposition of rocks in situ by the combined actions of the weather, plants and animals.

5. + 1 Water and wind erosion Rainfall intensity and runoff. The impact of raindrops on the soil surface. Gully and rill erosion Fine material Easily moved by rain splash and runoff water Greater raindrop energy required to move… …larger material – sand and gravel

6. + 1 Water and wind erosion Reduced infiltration (eg from soil compaction, or freezing) Excess water on a slope Increased surface run off Agricultural land Run off greatest in spring No vegetation cover and there is saturated ground

7. + 1 Water and wind erosion Slope gradient and length The steeper the slope the greater the loss of soil by erosion Vegetation Protects the soil from rain drop splash Slows down the movement of surface water

8. + 1 Water and wind erosion Erodibility of soil Unsheltered distance Vegetative cover

9. + Physical degradation Soil compaction caused by heavy machinery and animals Increases surface run off Decreases infiltration Prevent seeding emergence

10. + Chemical degradation Loss of nutrients in the soil can cause acidification – changes the chemical composition of the soil Acid rain – increased acidity of soil by acids in rain from fossil fuels Salinisation – occurs in dry (arid) areas. Capillary action draws slats to the surface of the soil. High rates of evaporation removes moisture leaving a slat layer on the surface.

11. + Biological degradation Organic matter = plants remains and POO POO. Loss of organic matter Reduces stability of the soil Can lead to the formation of soil crusts Reduces infiltration

12. + Climate and land use change If the climate change (remember the difference between weather and climate?) – we will have to rethink the way we use our land. We will have to adapt to new the new conditions whether they are wetter, dryer, colder or warmer.

13. + The impact of artificial fertilisers and pesticides If this graph was in a paper one exam. What question would go with it? It might be something like: STEM Study fig.6, it is a graph showing the world consumption of fertiliser 1961- 2001. QUESTION Describe the pattern of change in fertisier consumption 1961-2001 Of course, you’d remember the rules: 1.Read the stem 2.Study whatever it is – labels, key etc. 3.Read the question, identify the command word 4.Relook at at whatever it is 5.Answer the question 6.Describe the main patters 7.Use data in your answer 8.Any anomalies?

14. + Additional reading – all on the weebly and all really good! ‘Soil degradation in the UK’ J. Butler, Geography Review, Vol 25, No.3, Feb 2012, p22-25 ‘Managing soil erosion: a case study from Ireland’ D.Mullan & D. Favis-Mortlock, Geography Review, Vol 24, No 4, April 2011 ‘Soil erosion’ Wide World, Vol 23, No 3, p6-7 Just so you know: 1 – Geography Review is a brilliant magazine. It is aimed at geography students aged 16-18 2 – Wide World is made by the same people but is aimed at students aged 14-16, so their articles are easier but less detailed.