The Anthropocene Effect: Human Impact Erosion Quiz

If water gains speed as it flows down a long, steep slope, and if terracing breaks that slope into flat steps, then the water must stop and start at each level; if the water slows down, then it loses the energy needed to wash away soil.

If the earth's surface has layers, and if the uppermost layer contains the most organic matter and nutrients for plants, then that layer is the topsoil; the loss of this specific layer is topsoil erosion.

If tilling (plowing) breaks up soil and turns it over, making it loose, and if no-till farming avoids this by leaving crop residue on the surface, then the soil remains covered and anchored; if the soil is covered, then it is protected from wind and water.

If farmers plowed up the native grasses that held the soil and then a severe drought killed their crops, then the soil became dry and loose; if the soil was dry and loose with no plants to hold it, then the wind blew it away in massive clouds.

If surface mining requires stripping away all plants and topsoil to get to the rocks underneath, and if the remaining "spoil" is piled up loosely, then the land is completely exposed; if the land is exposed and loose, then erosion happens very quickly.

If the primary purpose of a cover crop (like clover or rye) is to protect the soil during the off-season rather than to be the main harvest, then its goal is conservation, not direct profit; therefore, the statement is false.

If soil is eroded into rivers, it becomes sediment; if the water is full of suspended soil particles, then fish cannot breathe through their gills; if the sediment settles, then it buries the places where aquatic organisms live and lay eggs.

If heavy weight is applied to wet soil, then the air and water spaces between particles are squeezed out; if the soil is compacted, then water cannot soak in; if water cannot soak in, then it runs off and erodes the surface.

If many people walk on the same path, then the plants are crushed and die; if the plants die and the soil is packed down, then water will flow down the trail like a stream; if water flows down the trail, then it will carve out a gully and remove the soil.

If a practice stops soil from leaving the site or prevents it from becoming airborne, then it is a BMP; silt fences and hay bales trap moving soil, seeds grow plants to anchor it, and water prevents wind erosion.

If a strip of grass or trees is left between a field and a stream, and if runoff flows through that vegetation, then the plants will slow the water and trap the soil particles; if the soil is trapped, then it does not pollute the stream.

If human activities like overgrazing and deforestation remove the vegetation that maintains soil moisture and stability, and if the topsoil then blows away, then the land can no longer support life; if the land can no longer support life, then it has undergone desertification.

If tree roots act as a physical net that anchors soil particles together, and if deforestation removes those roots, then the soil loses its stability; if the soil is unstable, then wind and water can easily transport it away.

If plants provide a protective cover that breaks the impact of raindrops, and if livestock eat the plants faster than they can grow back (overgrazing), then the soil surface becomes exposed; if the surface is exposed, then rain and wind can strike it directly and carry it away.

If natural vegetation acts as a barrier against erosion, and if construction requires clearing that vegetation and digging up the soil, then the protective layer is gone; if the protective layer is gone, then the erosion rate increases.

If water naturally flows downhill, and if furrows are plowed up and down the hill, then the water will accelerate in those channels; if furrows are plowed across the slope (contour plowing), then they act as small dams that slow the water down and prevent erosion.

If wind is a major agent of erosion in flat areas, and if a row of trees creates a physical obstruction that slows wind speed at ground level, then the wind will lose its power to lift soil; this specific barrier is called a windbreak.

If soil is covered by asphalt or concrete (impermeable surfaces), then rainwater cannot soak into the ground; if water cannot soak in, it must flow over the surface as runoff; if runoff volume increases, then it gains more energy to erode soil in adjacent unpaved areas.

If an activity removes plants or breaks up the soil structure, then it promotes erosion; logging, farming, mining, and road construction all involve significant land disturbance, whereas staying on trails minimizes the area affected.

If different plants provide different types of root structures and nutrients, and if monoculture uses only one type of plant, then the soil becomes uniform and often depleted; if the soil is depleted and lacks diverse root systems, then it is more susceptible to erosion.