Stormwater Exam 2 With 100% Correct Answers 2023

If I protect the soil surface from flow turbulence impact, what effects does that generally have on rill formation? Prevents rill formation What are the things that slowing the flow does to reduce hillslope detachment? Slowing the flow lessens the energy in turbulent eddies, gives runoff more time to infiltrate, and spreads out future flow. What factors cause diminution of the soil roughness over time? Erosion, weathering, soil content Under what condition might lots of vegetation not really slow down the flow? If the flow is large enough to knock the vegetation over, or in the case of kudzu where the vegetation forms a mat and the flow runs under the mat. Describe "contour tillage". tilling along lines of consistent elevation to conserve rainwater and reduce soil erosion. Complete the following phrase: "If you concentrate the flow...." You are responsible for the flow What is the key to strong soil aggregates? Organic Matter In what ways do subsurface vegetative material (e.g., roots) help stop hillslope detachment? absorbs water, adds roughage, deepens water table Besides protecting water quality, what are other goals of urban erosion and sediment control? Protection of vegetation, establish seeding, prevent pollutants What is the primary concern for urban erosion and sediment control generally limited to while construction is in process? Keeping eroded sediment on site. Construction sites are generally bare soil and are very susceptible to erosion. The main goal erosion wise is to prevent that sediment from leaving the construction site. Vegetation on construction sites should be removed no more than how many days before earth-moving begins? 14 days What are the benefits of compost compared to other mulches?- ---Heavier and stays in place better, more OM How do we usually stop sediment delivery from hillslopes? Stabilization practices- cover the bare area with something - mulch, straw etc. Also, stapled metal meshes and paving. Why is it important that buffer strips slow and spread the flow? less concentration inhibits the formation of rills How does a "graded terrace" get its collected water off the field? by having lanes of vegetation to absorb the runoff and erosion Why are specifically some of the problems with mining operations with respect to erosion control? keeping toxins and pollutants out of runoff Acidic mine spoils materials and drainage result from exposure to water and air of rock containing what? Pyrite