The component of the hydrologic cycle that returns water from land to atmosphere primarily through plants is:
A a) Infiltration
B b) Percolation
C c) Evapotranspiration
D d) Baseflow
It combines evaporation from surfaces and transpiration from plants.
The portion of rainfall that contributes to streamflow after satisfying losses is called:
A a) Interception
B b) Effective rainfall
C c) Depression storage
D d) Hygroscopic water
It is the rainfall excess available for runoff generation.
An unconfined aquifer is characterized by:
A a) Overlain by an aquitard and pressurized
B b) Water table as its upper surface
C c) No recharge from rainfall
D d) Zero permeability
Unconfined aquifers have a free water surface that fluctuates.
The law that relates discharge through a porous medium to hydraulic gradient is:
A a) Manning’s law
B b) Darcy’s law
C c) Chezy’s law
D d) Bernoulli’s principle
𝑄
=
𝐾
𝐴
𝑖
Q=KAi where
𝐾
K is hydraulic conductivity and
𝑖
i is gradient.
A unit hydrograph represents:
A a) Hydrograph for 1 m³/s baseflow
B b) Direct runoff hydrograph due to 1 cm (or 1 mm) effective rainfall in a given duration
C c) Daily average river stage curve
D d) Cumulative mass curve of rainfall
It is a linear response function of a watershed.
The time of concentration of a watershed is:
A a) Time from start of storm to peak rainfall
B b) Time for the most distant drop to reach the outlet
C c) Residence time of groundwater
D d) Lag time between rainfall and baseflow
After this time, the entire area contributes to runoff.
Infiltration capacity is maximum:
A a) At the end of a long storm
B b) Immediately after rainfall begins
C c) During baseflow recession
D d) During snowmelt only
It declines with time as soil becomes saturated.
The parameter indicating oxygen demand by microorganisms in water is:
A a) pH
B b) DO
C c) BOD
D d) TDS
Biological Oxygen Demand measures biodegradable organic pollution.
Safe yield of a groundwater basin refers to:
A a) Maximum pumping rate regardless of recharge
B b) Pumping equal to natural recharge without long-term depletion
C c) Zero drawdown pumping
D d) Maximum short-term yield during drought
Ensures sustainability of the aquifer.
The lowering of the water table around a pumping well is called:
A a) Cone of depression
B b) Artesian rise
C c) Perched mound
D d) Hydraulic jump
Drawdown forms a cone-shaped depression in potentiometric surface.
In flood frequency analysis, a return period of 50 years means:
A a) Flood occurs exactly every 50 years
B b) 2% probability of exceedance each year
C c) 50% probability each year
D d) Non-exceedance probability of 2% each year
Return period
𝑇
T corresponds to annual exceedance probability
1
/
𝑇
1/T.
The method commonly used to estimate reference evapotranspiration from weather data is:
A a) Rational method
B b) Penman–Monteith equation
C c) SCS Curve Number
D d) Muskingum routing
It combines energy balance and aerodynamic terms.
The Curve Number (CN) method is primarily used to estimate:
A a) Baseflow separation
B b) Peak discharge directly
C c) Rainfall excess (runoff) from storm rainfall
D d) Sediment yield
SCS-CN relates land use, soil, and antecedent moisture to runoff depth.
Riparian rights relate to:
A a) Groundwater ownership only
B b) Priority use by upstream dam operators
C c) Water use by landowners adjoining a natural watercourse
D d) Exclusive municipal allocation
A doctrine in water law granting reasonable use to riparian owners.
The most water-efficient surface irrigation method is typically:
A a) Border irrigation
B b) Basin flooding
C c) Furrow irrigation with surge
D d) Wild flooding
Surge furrow reduces infiltration opportunity time and losses.