Run-Off-Analysis

Question 1

means the draining or flowing off of precipitation from a catchment area through a surface channel.

Answer 1

Runoff

Question 2

This portion of the runoff

Answer 2

Overland Flow

Question 3

where it travels all the time over the surface as overland flow and through the channels as open-channel flow and reaches the catchment outlet

Answer 3

Surface Runoff

Question 4

It is the part of the runoff which enters the stream immediately after the rainfall.

Answer 4

Direct Run off

Question 5

The delayed flow that reaches a stream essentially as groundwater

Answer 5

Baseflow

Question 6

Runoff representing the response of a catchment to precipitation reflects the integrated effects of a wide range of catchment, climate and rainfall characteristics.

Answer 6

Natural Flow

Question 7

is therefore stream flow in its natural condition. i.e., without human intervention.

Answer 7

True Runoff

Question 8

mathematical equations whose free parameters we have to specify by a given set of experimental data about a particular state to obtain formulas for predicting other data about this state. Empirical formulas, curves, and tables are based on different regions.

Answer 8

Empirical Formulas

Question 9

are graphical representations that depict the relationship between two or more hydrological parameters.

Answer 9

Empirical Curves

Question 10

are widely used in hydrology to provide quick reference information for estimating various hydrological parameters.

Answer 10

Empirical Tables

Question 11

Empirical Formulas Based on Different Regions

Answer 11

I. Johnstone and Cross
II. Snyder’s Method

Question 12

○ proposed one of the first relationships for t, the time of concentration in hours

Answer 12

Johnstone and Cross (US, 1949)

Question 13

was the first to develop a synthetic UH based on a study of watersheds in the Appalachian Highlands. In basins ranging from 10 to 10,000 mi2

Answer 13

Snyder’s Method

Question 14

2 Dominant Methods of flood estimation in the Philippines

Answer 14

1. Hydrometeorological
2. Flood frequency method

Question 15

Also known as “Precipitation Characteristics”.

Answer 15

Storm Characteristics

Question 16

7 Storm Characteristics

Answer 16

a. Type or nature of storm and season
b. Intensity
c. Duration
d. Areal extent
e. Frequency
f. Antecedent Precipitation
g. Direction of storm movement

Question 17

7 Storm Characteristics

Answer 17

a. Type or nature of storm and season
b. Intensity
c. Duration
d. Areal extent
e. Frequency
f. Antecedent Precipitation
g. Direction of storm movement

Question 18

Factors Affecting Runoff

Answer 18

Storm
Meteorological
Basin
Storage

Question 19

4 Meteorological Characteristics

Answer 19

a. Temperature
b. Humidity
c. Wind Velocity
d. Pressure Variation

Question 20

Two Types of Catchments

Answer 20

1. Fan Shaped Catchment
2. Fern Leaf Catchment

Question 21

Runoff Estimation Methods

Answer 21

a. Empirical Formula, Curves and Table
b. Infiltration Method
c. Rational Method
d. Overland Flow Hydrograph
e. Unit Hydrograph Method

Question 22

is that balance of rain water, which flows or runs over the natural ground surface after losses by evaporation, interception and infiltration.

Answer 22

Runoff

Question 23

of a catchment (usually means yield) is the net quantity of water available for storage, after all losses, for the purposes of water resources utilization and planning, like irrigation, water supply, etc.

Answer 23

yield

Question 24

is the discharge in times of flooding of the catchment area, when the intensity of rainfall is greatest and the condition of the catchment regarding humidity is also favorable for an appreciable runoff.

Answer 24

Maximum flood discharge

Question 25

is the movement of water from the soil surface into the soil. As long as the rate of water addition to the soil is slower than the rate of infiltration, water will move into the soil, and there will be no runoff.

Answer 25

Infiltration

Question 26

The capacity decreases with time and ultimately reaches a constant rate, caused by filling of soil pores with water, which reduces capillary suction.

Answer 26

Horton’s Infiltration Capacity curve

Question 27

showed that when the rainfall rate i exceeds the infiltration rate f, water infiltrates the surface soils at a rate that generally decreases with time.

Answer 27

Horton (1933)

Question 28

One of the most commonly used procedures for calculating peak flows from small drainages less than 200 acres is the Rational Method. This method is most accurate for runoff estimates from small drainages with large amounts of impervious area. Examples are housing developments, industrial areas, parking lots, etc.

Answer 28

RATIONAL METHOD

Question 29

Basin outflow resulting from one unit of direct runoff generated uniformly over the drainage area ay a uniform rainfall rate during a specified period of rainfall duration.

Answer 29

UNIT HYDROGRAPH METHOD

Question 30

Three Types of Hydrographs

Answer 30

1. Flood Hydrograph 2. Direct Runoff Hydrograph 3. Unit Hydrograph

Question 31

graphs that show how a drainage basin responds to a period of rainfall

Answer 31

Flood Hydrograph

Question 32

obstructions and losses are deducted but the results of excess precipitation do not equal to 1 inch.

Answer 32

Direct Runoff Hydrograph

Question 33

results in 1 inch of excess precipitation.

Answer 33

Unit Hydrograph

Question 34

one method to develop hydrograph.

Answer 34

Linear Superposition Method