A small stream runs through the center of a residential neighborhood. Recently, there has been an increase in building in the area. New homes, new streets, and new storm drains have impacted the area. What effect have the changes likely had on the neighborhood stream?
A.The water level has risen and is flowing more slowly. The stream is depositing sediment.
B.The water quality has been drastically changed due to contact with the pavement. The number of species in the creek has decreased.
C.The increase in paved areas has increased the amount of water flowing into the creek. The streambank has eroded.
D.The amount of water flowing into the stream has decreased. The stream is flowing more quickly.
Answers
Answer:
A mass of mineral matter that makes up the crust of the earth is called rock.
Or
Aggregates of minerals are termed as rocks. Examples: See part
Three Types of Rocks
Igneous Rocks
Sedimentary Rocks
Metamorphic Rocks.
Explanation:
Answer:
After a heavy rainfall you might see sheets of water running downhill...always seeking a stream it can run into, so it can continue to participate in the natural water cycle.
When rain falls onto the earth, it just doesn't sit there, it starts moving according to the laws of gravity. A portion of the precipitation seeps into the ground to replenish Earth's groundwater. Most of it flows downhill as runoff. Runoff is extremely important in that not only does it keep rivers and lakes full of water, but it also changes the landscape by the action of erosion. Flowing water has tremendous power—it can move boulders and carve out canyons; check out the Grand Canyon!
Runoff of course occurs during storms, and much more water flows in rivers (and as runoff) during storms. For example, in 2001 during a major storm at Peachtree Creek in Atlanta, Georgia, the amount of water that flowed in the river in one day was 7 percent of all the streamflow for the year.
Some definitions of runoff:
1. That part of the precipitation, snow melt, or irrigation water that appears in uncontrolled (not regulated by a dam upstream) surface streams, rivers, drains or sewers. Runoff may be classified according to speed of appearance after rainfall or melting snow as direct runoff or base runoff, and according to source as surface runoff, storm interflow, or groundwater runoff.
2. The sum of total discharges described in (1), above, during a specified period of time.
3. The depth to which a watershed (drainage area) would be covered if all of the runoff for a given period of time were uniformly distributed over it.
Meteorological factors affecting runoff:
Type of precipitation (rain, snow, sleet, etc.)
Rainfall intensity
Rainfall amount
Rainfall duration
Distribution of rainfall over the watersheds
Direction of storm movement
Antecedent precipitation and resulting soil moisture
Other meteorological and climatic conditions that affect evapotranspiration, such as temperature, wind, relative humidity, and season.
Physical characteristics affecting runoff:
Land use
Vegetation
Soil type
Drainage area
Basin shape
Elevation
Slope
Topography
Direction of orientation
Drainage network patterns
Ponds, lakes, reservoirs, sinks, etc. in the basin, which prevent or alter runoff from continuing downstream
Runoff and water quality
A significant portion of rainfall in forested watersheds is absorbed into soils (infiltration), is stored as groundwater, and is slowly discharged to streams through seeps and springs. Flooding is less significant in these more natural conditions because some of the runoff during a storm is absorbed into the ground, thus lessening the amount of runoff into a stream during the storm.
As watersheds are urbanized, much of the vegetation is replaced by impervious surfaces, thus reducing the area where infiltration to groundwater can occur. Thus, more stormwater runoff occurs—runoff that must be collected by extensive drainage systems that combine curbs, storm sewers (as shown in this picture), and ditches to carry stormwater runoff directly to streams. More simply, in a developed watershed, much more water arrives into a stream much more quickly, resulting in an increased likelihood of more frequent and more severe flooding.
Storm sewer drain
What if the street you live on had only a curb built around it, with no stormwater intake such as the one pictured here. Any low points in your street would collect water when it rained. And if your street was surrounded by houses with yards sloping uphill, then all the runoff from those yards and driveways would collect in a lake at the bottom of the street. (Credit: Robert Lawton)
A storm sewer intake such as the one in this picture is a common site on almost all streets. Rainfall runoff, and sometimes small kids' toys left out in the rain, are collected by these drains and the water is delivered via the street curb or drainage ditch alongside the street to the storm-sewer drain to pipes that help to move runoff to nearby creeks and streams. ; storm sewers help to prevent flooding on neighborhood streets.
Drainage ditches to carry stormwater runoff to storage ponds are often built to hold runoff and collect excess sediment in order to keep it out of streams.
Runoff from agricultural land (and even our own yards) can carry excess nutrients, such as nitrogen and phosphorus into streams, lakes, and groundwater supplies. These excess nutrients have the potential to degrade water quality.
Explanation: