In this unit, students investigate interactions between land and water. Through their experiences, students are introduced to the following concepts, skills, and attitudes.

• Water has an important role in shaping the land on earth.
• Soil is a composite of weathered materials and organic matter at the earth’s surface. Soil components include sand, silt, clay, gravel, and humus. Each soil component has unique properties.
• The wearing away and moving of soil and rock is erosion; the settling of eroded materials is deposition.
• The water cycle includes the processes of evaporation, condensation, and precipitation and the passage of water over and through land. These processes affect the shape of the land.
• Both the flow of water and the slope of the land affect erosion and deposition.
• Tributaries are branches of streams that converge to form the trunk of a larger stream, or river. Together, they act as a system that drains the land.
• Land forms, such as canyons and deltas, result from the action of flowing water.
• Humans can affect erosion and deposition in various ways, including clearing the land, planting vegetation, and building dams.
• Hills, rocks, plants, and dams may change the direction and flow of water.
• Aerial photographs are views of land or other surfaces as seen from above.

Skills

• Using stream table materials to investigate the interactions between water and land.
• Analyzing the materials that make up land and describing these materials on the basis of their properties.
• Testing the porous and adhesive qualities of earth materials.
• Comparing the changes in land created by water flowing over and through soil in a stream table.
• Relating stream table results to natural processes.
• Communicating the results of an investigation through record sheets, oral and written observations, and drawings.
• Investigating the effects of slope, flow, and natural land formations on erosion and deposition.
• Creating and labeling aerial drawings.
• Designing and building models of dams to test the effects of dams on land and water interactions.
• Designing and building models of landscapes, predicting how a landscape will affect the flow of water, and relating these modeled effects to land and water interactions on earth.
• Implementing a planned investigation and making and validating predictions.
• Identifying evidence within a model to support observations and conclusions.

Attitudes

• Recognizing the importance of models for investigating processes too large or complex to study firsthand.
• Developing an interest in the interactions between land and water and recognizing these interactions in the real world.
• Accepting that humans can attempt to control and affect the interactions between land and water.
• Appreciating the role that plants play in curbing erosion and runoff.
• Recognizing the role humans play in planning and designing landscapes that take into account the natural interactions of land and water.
• Recognizing the importance of models for investigating processes too large or complex to study firsthand.
• Developing an interest in the interactions between land and water and recognizing these interactions in the real world.
• Accepting that humans can attempt to control and affect the interactions between land and water.
• Appreciating the role that plants play in curbing erosion and runoff.
• Recognizing the role humans play in planning and designing landscapes that take into account the natural interactions of land and water.