Hydrology Flashcards
Method of areal rainfall estimation done by getting the weighted average.
A. Averaging method
B. Arithmetic method
C. Polygon Method
D. Isohyetal method
Arithmetic method
An instrument to measure rainfall depth.
A. Rain gage
B. Rainfall dip stick
C. Bucket
D. Rainfall meter
Rain gage
Is that part of rainfall which runs off the soil as surface or subsurface flow.
A. Flood
B. Infiltration
C. Percolation
D. Runoff
D. Runoff
The ratio of runoff over rainfall.
A. Runoff ratio
B. Runoff/rainfall ratio
C. Runoff coefficient
D. Rainfall ratio
C. Runoff coefficient
A drop of water greater than 0.5 mm falling from the atmosphere.
A. Atmospheric rainfall
B. Torrential rainfall
C. Precipitation
D. Effective rainfall
D. Effective rainfall
Kind of thermometer with constriction to prevent easy return of liquid to the bulb.
A. Maximum thermometer
B. Minimum thermometer
C. Air thermometer
D. Autothermometer
D. Autothermometer
The inverse of the probability of exceedance of a certain hydrologic event.
A. Return period
B. Probability of inceedance
C. Hydro probability
D. Event probabilty
A. Return period
Natural airmass lifting process facilitated by sunlight.
A. Natural
B. Orographic
C. Mountain lifting
D. Convective
D. Convective
Natural airmass lifting process facilitated by mountain formation.
A. Natural
B. Orographic
C. Mountain lifting
D. Convective
B. Orographic
Dominant form of precipitation in the Philippines.
A. Rainfall
B. Flood
C. Runoff
D. Evaporation
A. Rainfall
Probability of occurrence in any year of hydrologic event recurring once in 2 years.
A. 20% B. 2% C. 100% D. 50%
D. 50%
Prob. = (1/return period) x 100 = (1/2) x 100 = 50%
Area which contributes runoff or drains water into the reservoir (AMTEC, 2016 - PAES 609:2016).
A. River basin
B. Runoff reservoir
C. Watershed
D. Drainage divide
C. Watershed
A thermometer that has a constriction above the bulb that permits the mercury to rise in the capillary tube but does not allow it to descend the capillary tube unless the thermometer is reset (PAGASA, 2022)
A. Minimum thermometer
B. Maximum thermometer
C. Air thermometer
D. Constricthermometer
B. Maximum thermometer
The science that encompasses the occurence, distribution, movement and properties of the waters of the earth and their relationship with the environment (USGS, 2022)
A. Meteorology
B. Hydrometeorology
C. Hydrology
D. Limnology
Hydrology
The study of the biological, chemical, and physical features of lakes and other bodies of fresh water (Oxford Languages, 2022)
A. Meteorology
B. Hydrology
C. Hydrometeorology
D. Linmology
D. Linmology
A branch of meteorology and hydrology that studies the transfer of water and energy between the land surface and the lower atmosphere.
A. Meteorology
B. Hydrometeorology
C. Hydrology
D. Linmology
B. Hydrometeorology
Heavy rainfall or rain that accumulates at a rate of 3 tenths of an inch (0.3 inch or about 7.5 mm), or more, per hour (US National Weather Service, 2022)
A. Storm
B. Typhoon
C. Torrential rain
D. Heavy rain
Torrential rain
Kind of thermometer with pin inside its tube which does not go with the expanding liquid when temperature increases.
A. Maximum thermometer
B. Minimum thermometer
C. Air thermometer
D. Soil thermometer
B. Minimum thermometer
The part of rainfall that is stored in the root zone and can be used by the plants (FAO, 2022). This excludes rainfall that does not reach the soil and percolation below the root zone. For grassed soil surface, it is estimated that this rainfall is greater than 0.5 mm/day.
A. Atmospheric rainfall
B. Effective rainfall
C. Precipitation
D. Torrential rainfall
B. Effective rainfall
Airmass lifting process which is mountain-facilitated.
A. Natural
B. Convective
C. Mountain lifting
D. Orographic
D. Orographic
Airmass lifting process facilitated by sunlight or heating.
A. Natural
B. Convective
C. Mountain lifting
D. Orographic
B. Convective
Indicates to what depth liquid precipitation would cover a horizontal surface in an observation period if nothing could drain, evaporate or percolate from this surface (Graf-Water, 2022).
A. Precipitation
B. Precipitation depth
C. Rainfall depth
D. Water depth
B. Precipitation depth
The precipitation depth that corresponds to a liquid quantity of 1 liter falling into a 1 square meter of ground area.
A. 0.5 mm
B. 1 mm
C. 2 mm
D. 2.5 mm
B. 1 mm
Dp = (1 L /m2) (1m3/1000L)(1000mm/1m) = 1 mm
Probability of occurence in any year of hydrologic event recurring once in 4 years.
A. 40%
B. 25%
C. 20%
D. 50%
B. 25%
Probability = (1/Return Period) x 100 = (1/4) x 100 = 25%
What is the probability of occurrence in any year of a hydrologic event recurring every year?
A. 100%
B. 10%
C. 20%
D. 50%
Probability = (1/Return Period) x 100 = (1/1) x 100 = 100%
Rainfall depths recorded were as follows: 8 mm and 2 mm for 8:00 A.M. and 2:00 P.M., respectively on 7-7-2022 and 5 mm and 9 mm for 8:00 A.M. and 2:00 P.M., respectively on 7-8-2022. What is the total rainfall depth on 7-7-2022?
A. 5 mm
B. 2 mm
C. 7 mm
D. 9 mm
C. 7 mm
The rainfall recorded at 8:00 AM of any day is counted as part of the total rainfall for the previous day.
Rainfall on 7-7-2022 = Rainfall at 2:00 PM on 7-7-2022 + Rainfall at 8:00 AM on 7-8-2022
Rainfall on 7-7-2022 = 2 mm + 5 mm = 7 mm
The agrometeorological station uses electronic rain gage. The rainfall depths were recorded on
June 1, 2022 as follows: 2 mm from 6:00 to 8:00 A.M., 7 mm from 8:00 to 10:00 A.M., 9 mm from 12:00 noon to 2:00 P.M., and zero rainfall for all other times of the day and the previous
day. What is the rainfall intensity recorded on June 1, 2022?
A. 0.75 mm/hr
B. 2 mm/hr
C. 4 mm/hr
D. 3 mm/hr
C. 4 mm/hr
Intensity =Depth/Time, time is from 8:00 AM of current day to 8:00 AM of the next day
Intensity = (7 mm from 8:00 to 10:00 AM + 9 mm from 12:00 noon to 2:00 PM)/(2hr + 2hr)
Intensity = 4 mm/hr
Estimate the time of concentration of a certain watershed having a time lag of 1 hour.
A. 1.43 hrs
B. 1.34 hrs
C. 14.3 hrs
D. 13.4 hrs
A. 1.43 hrs
Using the formula for time of concentration from PAES 609:2016,
T_c = T_L / 0.70
T_c = 1 hr/0.70
T_c = 1.43 hrs
