PPT-Erosion

Rain Splash Sheet Rill Gully Heavy rains in northwest Iowa washed away soil leaving this scarred tableau This type of erosion termed sheetandrill erosion occurs when there is insufficient vegetation to hold soil in place As rain falls it forms sheets of surface water that transport soil away As more water accumulates it forms runoff channels called rills which further displace soil. Soil erosion and sediment control is not a new technology The USDA Soil Conservation Service and a number of State and local agencies have been developing and promoting the use of erosion and sediment control devices for years This chapter provides Features of River Erosion. 1. Potholes. 2. River Valleys. 3. Gorges and Canyons. 4. Mesa and Butte. 5. Waterfalls. 1. Potholes. Potholes are formed due to stream or river erosion which initiates by simple . Chad Lentz. Why Care?. Removes valuable topsoil. Carries away expensive nutrients. Increase tillage costs to fix. Creates algae blooms and dead zones due to excess nutrients in waterways. Types of Erosion. Chapter 4.1. Pages 118-127. Key Questions. How does moving water cause erosion?. What land features are formed by water erosion and deposition?. Moving water is the major agent of the erosion that has shaped Earth’s land surface.. Physical Weathering. Weathering. is the breakdown of rock or soil. . Physical . weathering occurs when natural forces, such as wind, running water, and moving ice, physically break up rock and soil into smaller particles. . Chapter 7. Section 7.1 Weathering. Weathering is the process by which rocks on or near Earth’s surface break down and change. . Erosion is the removal and transport of weathered material from one location to another.. The . surface. features of the Earth change as a result of observable physical and chemical processes . Weathering and Erosion. This is a monument . called Cleopatra’s . Needle. It was carved in Egypt around 1450B.C. The sides are carved with hieroglyphs, the writing of ancient Egypt. It stood in the dry, hot Egyptian desert for over 3000 years. During that time, the hieroglyphs remained distinct.. Learning objectives. To be able to . define. the . five . processes of . marine coastal . erosion. .. To be able to . explain. the . factors. . affecting coastal erosion.. To describe . the difference between concordant and discordant . PROCESSES. Generate runoff. Saturation excess. Infiltration excess. INFLUENCES. Hydraulic soil properties. Conductivity. Compaction/use history. Ground cover (interception). Antecedent conditions. Existing moisture. Weathering. Weathering is the process that breaks down rock and other substances at the Earth’s surface. . Heat, cold, water, and ice all contribute to weathering.. Repeated freezing and thawing for example can crack rock apart into smaller pieces. . Scenario #1. Flood water pounds against a canyon wall and wears it down.. Weathering. Scenario #2. Rain washing soil away from a hillside. Erosion. Scenario #3. Layers of sediment forming at the bottom of the ocean. erosion is the process by which the products of weathering are transported. agents of erosion are gravity, wind, glaciers, water, ocean waves, currents streams, groundwater. What is erosion?. What is Soil Erosion?. Contrast. the features left from different types of erosion.. Analyze. the impact of living and nonliving things on the processes of weathering and erosion.. Erosion and Deposition. Section 7.2. gravity: . another.. 2 . kinds:. 1) . Rill erosion. is the erosion by running water in small channels. , on the side of a slope.. 2) . Gully erosion. is when a rill channel evolves to become deep and wide..