Terms of Hydrology (N)

nadir :

In remote sensing, point on the ground vertically beneath the perspective c ...

nappe :

Sheet of water overflowing a weir or other structure.

natural control :

Reach of a stream channel where natural conditions exist that make the wate ...

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 sediment ...

natural regulation :

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

neap tide :

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

near infrared :

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

net balance (of glacier) :

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

net radiation :

Difference between downward and upward (total and terrestrial) radiation ne ...

net storm rain :

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

neutron logging :

Vertical recording of induced neutron reactions, especially sensitive to th ...

neutron-scattering method :

Method for measuring soil moisture based on the scattering and slowing down ...

new snow :

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

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 calcium and magn ...

non-modular flow :

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

non-structural flood mitigation :

System for reduction of the effects of floods using non-structural means, e ...

non-uniform flow :

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

non-wetting liquid :

Liquid whose contact angle with another substance exceeds 90°.

normal distribution :

Mathematically defined, symmetrical, bell-shaped, continuous probability di ...

normal hydrological value :

Mean value of a hydrological characteristic taken over a period selected by ...

normals :

Period averages of meteorological/hydrometeorological elements calculated o ...

nucleus (condensation, crystallization) :

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

nutrient :

Substance, element or compound necessary for the growth and development of ...

n-year event :

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