LE8 - STREAMS AND FLOODING

Question 1

The basic role of streams and rivers

Answer 1

To drain water off the landscape and to transport sediments

Question 2

A stream may overflow its banks when its ability to carry water is overwhelmed by the sheer volume of water flowing off the landscape and create

Answer 2

Flood

Question 3

Humans tend to concentrate their settlements along waterwats plus relatively frequent nature of flooding puts large number of people and buildings at

Answer 3

Risk

Question 4

Historically, people take Advantages of living along rivers, why?

Answer 4

Water supply, fertile soils, and ability to transport goods

Question 5

Described as the voume of water moving through a channel over a given time interval, commonly measured in units such as cubic feet per sec. Ft³/s

Answer 5

Stream discharge

Question 6

Process where water flows through stream channels

Answer 6

Runoff

Question 7

Precipitation reaching the land surface moves downslope in tuin sheets

Answer 7

Overland flow

Question 8

Allows water to return back to the atmosphere

Answer 8

Evaporation and plant transpiration

Question 9

Discharge of groundwater into the surface environment

Answer 9

Groundwater basèflow

Question 10

Groundwater may travel anywhere from a few days to thousand of years before discharging into a stream channel

Answer 10

Sporadic input of water to a stream

Question 11

Process of Stream Discharge

Answer 11

Precipitation that falls onto land surface can take different paths through the hydrologic cycle, some of the water moves overland dlow and enters directly into stream channeos, most of the remaining water infiltrates the soil zone where it can return to the atmosphere via evaporation and plant transpiration. If soil moisture becomes great enough, infiltrating water can reach the water table and eventually flow with the grounwater system and discharge into the stream channel.

Question 12

Provides information about river or stream by simple plottinf the discharge by time

Answer 12

Stream hydrographs

Question 13

amount of time for water to move across the landscape and into the channells

Answer 13

lag time

Question 14

lag time varies depending on the

Answer 14

distance between where the rain is falling and the particular channel where discharge is being measured

Question 15

continuous input of groumdwater baseflow allows streams in many areas to keep flowing at some minimum level called…

Answer 15

baseflow conditions

Question 16

groundwater baseflow keeps streams from…. is also critical in maintaining the health of stream ecosystems

Answer 16

going dry between rain events

Question 17

high precipitation allows more water to infiltrate to the water table which causes the water table in humid regions to be higher than the stream channel, forcing groundwater to ________________ also called as _______.

Answer 17

flow into streams, gaining streams

Question 18

high precipitation allows more water to infiltrate to the water table which causes the water table in humid regions to be higher than the stream channel, forcing groundwater to ________________ also called as _______.

Answer 18

flow into streams, gaining streams

Question 19

____ result of less deep infiltration in arid areas resulting in a water table that is below the level of most stream channels, where the water in the stream will _____

Answer 19

losing streams, flow into the groundwater system

Question 20

stream hydrographs are useful because?

Answer 20

it helps analyze how stream discharge change overtime

Question 21

overland flow from heavy rains creates ____ in discharge, which can be large enough to cause streams to overflow their banks and flood low-lying areas.

Answer 21

spike

Question 22

water that infiltrates and slowly makes its way to a stream through the groundwater systems provides a steady supply of water called_____

Answer 22

baseflow

Question 23

groundwater baseflow enables stream to ____ between precipitation events

Answer 23

keep flowing

Question 24

a network of stream channel where merging tributaries form progressively larger streams

Answer 24

drainage system

Question 25

often applied to the larger stream that serves as the principal channel within a drainage system.

Answer 25

river

Question 26

the upper portion of the river is called ____ usually small and relatively fast moving occupy narrow valleys, and ________ is the lower part of the system where a river empties to an ocean, lake or another river which are gently flowing that occupy wider valleys.

Answer 26

headwater; mouth

Question 27

individual systems are separated from one another by a tp[pgraphic high or crest in the landscape called a …

Answer 27

drainage divide