What’s a landform? Physical shapes of the land such as hillsides, cliffs and marshes are some examples.

Erosion

Erosion

Erosion

What’s the difference between weathering & erosion? Weathering can take place in various manners: Physical or Mechanical – rocks breaking due to wind, rain, ice (natural forces) or human activity Burrowing animals or plant roots wedging rock apart Chemical – rocks change due to different chemical reactions – such as mild acid from rain deteriorates rocks, paint, or building surfaces or water & iron oxidize to become rust.

What’s the difference between weathering & erosion? Weathering – rocks & particles stay in one place Erosion – process of breaking rocks into particles (smaller pieces) and having them move (by wind or water or ice)

Deposition Deposition is when those particles or rocks have been moved and are then left in another place!

Earth Processes Weathering, Erosion & Deposition have been occurring for billions of years. (These are known as Earth processes.) Natural factors affect the rate of these processes Natural factors are: wind, water (rain), ice (glaciers) Human activities can accelerate the Earth processes. Construction & farming are 2 activities that cause the most erosion. These activities break apart rocks. Soil & plant roots hold land in place. Sediments can also carry pollution and toxic materials (pesticides) to new areas.

Positive/Negative of Erosion Positive effects of erosion – slow & steady water erosion creates lakes, rivers, hills, canyons, fertile plains. Negative effects of erosion – slow & steady water erosion can cause collapse of roads & buildings.

Positive /Negative - Deposition Positive effects of deposition – adds nutrients to soil creating fertile floodplains, building landforms such as deltas, forms rocks after long periods of time; like sandstone. Negative effects of deposition – building up & filling in rivers, lakes, wetlands, covering habitat areas needed by fish & animals, clogs pipes which provide water to cities & towns, also causes waterways to become shallow

Topographical Maps Topographical maps show the contour or elevation of the Earth’s surface. A contour line is an imaginary line on the Earth’s surface connecting points of the same elevation. A contour interval shows the differences in elevation between adjacent contour lines. When there is a lot of space between contour lines, the land is relatively flat. When the contour lines begin to move closer together, the terrain or area is steep as indicative of mountains or hills.