Nullah_Between_Mane_Villages_Spiti_Jun18_DSC05448

A nullah or nala (

Hindustani Hindustani may refer to: * something of, from, or related to Hindustan (another name of India) * Hindustani language, an Indo-Aryan language, whose two official norms are Hindi and Urdu * Fiji Hindi, a variety of Eastern Hindi spoken in Fiji, and ...

or "nallah" in

Punjabi Punjabi, or Panjabi, most often refers to: * Something of, from, or related to Punjab, a region in India and Pakistan * Punjabi language * Punjabi people * Punjabi dialects and languages Punjabi may also refer to: * Punjabi (horse), a British Th ...

) is an 'arm of the sea',

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a stream ...

, or watercourse, a steep narrow valley. Like the wadi of the Arabs, the nullah is characteristic of mountainous or hilly country where there is little rainfall. In the drier parts of India and Pakistan, and in many parts of

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, there are small steep-sided valleys penetrating the hills, clothed with rough brushwood or small trees growing in the stony soil. During occasional heavy rains, torrents rush down the nullahs and quickly disappear. There is little local action upon the sides, while the bed is lowered, and consequently these valleys are narrow and steep. In cities on the Delhi plain in India, nullahs are concrete or brick-lined ditches about deep and wide, used to divert monsoon rain away from the cities. Encroachment into nullahs is a significant problem in many South Asian cities, since it hampers the drainage of

stormwater Stormwater, also spelled storm water, is water that originates from precipitation (storm), including heavy rain and meltwater from hail and snow. Stormwater can soak into the soil ( infiltrate) and become groundwater, be stored on depressed la ...

and can exacerbate floods.

Canal

In East Asia, a nullah () refers to an open, usually concrete-lined

channel Channel, channels, channeling, etc., may refer to: Geography * Channel (geography), in physical geography, a landform consisting of the outline (banks) of the path of a narrow body of water. Australia * Channel Country, region of outback Austral ...

designed to allow rapid drainage of stormwater or industrial wastewater from high ground, to prevent flooding or stagnation in urbanised coastal areas, and basically is an often dry canal used as a reserve drain. One such example is the Kai Tak Nullah in Hong Kong.

References

;Attribution *{{1911, wstitle=Nullah Valleys Hindi words and phrases Geography of India Indian English idioms Water in India Urdu-language words and phrases