Terms of Hydrology (N)

nadir :

In remote sensing, point on the ground vertically beneath the per ...

nappe :

Sheet of water overflowing a weir or other structure.

natural control :

Reach of a stream channel where natural conditions exist that mak ...

natural flow :

Flow in a stream as would occur under natural conditions.

natural levee :

Low alluvial ridge adjoining the channel of a stream, composed of ...

natural regulation :

Smoothing-out of variations in streamflow as a result of storage ...

neap tide :

Tide with small amplitude occurring twice a month, near the time ...

near infrared :

Preferred term for the shorter wavelengths in the infrared region ...

net balance (of glacier) :

Difference between accumulation and ablation of a glacier usually ...

net radiation :

Difference between downward and upward (total and terrestrial) ra ...

net storm rain :

Portion of rainfall during a storm which reaches a stream channel ...

neutron logging :

Vertical recording of induced neutron reactions, especially sensi ...

neutron-scattering method :

Method for measuring soil moisture based on the scattering and sl ...

new snow :

(1) Recent snow deposit in which the original form of the ice cry ...

nominal particle diameter :

Diameter of a sphere of the same volume as a given particle.

non-carbonate hardness :

Hardness of water resulting from the presence of dissolved calciu ...

non-modular flow :

Flow over a weir or through a flume when the upstream water level ...

non-structural flood mitigation :

System for reduction of the effects of floods using non-structura ...

non-uniform flow :

Flow in which the velocity vector is not constant along every str ...

non-wetting liquid :

Liquid whose contact angle with another substance exceeds 90°.

normal distribution :

Mathematically defined, symmetrical, bell-shaped, continuous prob ...

normal hydrological value :

Mean value of a hydrological characteristic taken over a period s ...

normals :

Period averages of meteorological/hydrometeorological elements ca ...

nucleus (condensation, crystallization) :

Special minute particle or ion on which operates the passage from ...

nutrient :

Substance, element or compound necessary for the growth and devel ...

n-year event :

Magnitude of a hydrological event, the return period of which is ...