My Shed be Flooded/Maps
What is a watershed?
The land area that drains to a common outlet.
What is the volume of water passing a cross-section per unit time called?
Discharge.
What is the upper surface of the saturated underground zone called?
The water table.
What is the process by which water changes from liquid to vapor at Earth's surface?
Evaporation.
What is the wearing away and removal of rock or soil by water called?
Erosion.
On a USGS topographic map, contour lines form a V pointing upstream where they cross a stream. Which way does the stream flow?
Downstream, opposite the point of the V.
Which channel pattern commonly forms where sediment supply is high and discharge varies: braided or meandering or loose?
Braided.
What property is the percentage of a rock or sediment's volume made up of open spaces?
Porosity.
A summer lake has warm surface water above cold deep water, separated by a zone of rapid temperature change. Name that zone.
The thermocline.
A flood has a 1% chance of being equaled or exceeded in any given year. What is its annual exceedance probability and common recurrence-interval label?
1% annual exceedance probability; a 100-year flood.
A stream drops 120 m over a horizontal distance of 6 km. What is its average gradient in m/km?
20 m/km.
A river erodes its outer bank and deposits sediment along its inner bank at a bend. Name both features.
Cut bank (outer); point bar (inner).
What property describes how easily water moves through connected pore spaces or fractures?
Permeability.
What are waterlogged ecosystems such as marshes and bogs called?
Wetlands.
What happens to a river's sediment load when a dam traps much of the sediment upstream?
Downstream sediment supply decreases; downstream erosion may increase.
A river's tributaries form a branching, tree-like network over uniform substrate. Name this drainage pattern.
Dendritic drainage.
What property describes the largest particle size a stream can transport?
Competence.
Groundwater head is 140 m at well A and 110 m at well B. The wells are 1,000 m apart. What is the hydraulic gradient from A to B?
0.03, directed from A toward B.
A lake receives 80 cm of water from precipitation and inflow and loses 65 cm through evaporation and outflow. Ignoring other terms, what is the net change in storage?
A gain of 15 cm.
A watershed is paved with roads and parking lots. Predict two likely changes to storm runoff.
Faster and greater runoff, shorter lag time, and often a higher peak discharge and reduced infiltration.
A stream has a channel length of 15 km and a straight-line valley length of 10 km. Calculate sinuosity.
1.5.
Using Q = A × v, find discharge for a channel cross-sectional area of 8 m² and mean velocity of 1.5 m/s.
12 m³/s.
A stream disappears into a limestone opening and later emerges at a spring. What landscape system is likely present?
Karst terrain or a karst drainage system.
What is the name of the lake that notably changed names and appears different on different maps?
A river carries 2,400 kg of suspended sediment past a station in 60 seconds. What is the average sediment transport rate in kg/s?
40 kg/s.