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CHAPTER - II
RIVERS, STORAGEAND DISTRIBUTION OF
SURFACE WATER
Rainfall and snow melt are the main sources of water. Water that flows over the
surface and is visible is commonly known as Surface Water. Water that seeps
underground is known as groundwater. Surface water flows through definite
channels, i.e. rivers, streams etc. Flow of rivers has influenced the human
habitation and its propriety in a way that no natural resources can
compare. In general, most of the rivers originate from the hills. Innumerable
streams which are fed by water from the catchment joins the main river. These
small streams or rivers are termed tributaries to the main river. The area from
where these innumerable streams or rivulets originate is the catchment area of
the main river. The main river while flowing may part with some of its discharge
through small streams during its passage from the hills to oceans are known as
distributaries.
Rivers are classified as (a) Hill Rivers and (b) Rivers in the plains.
Hill Rivers :
These rivers have got two stages during this journey : (a) Incised
or Rocky River State and (b) Boulders Rivers State.
(a)
Incised or Rocky River State (Upper reaches) : In this type, the flow
channel is generally formed by the process of degradation. The sediment
transported in this reach is often different from the river bed material, since
most of it comes from the catchment due to denudation and soil erosion. These
river reaches are highly steep with swift flow, and forming rapids along their
courses. The beds and banks of such rivers are less susceptible to erosion.
(b)
Boulder River State (Upper reaches) : The river bed in these reaches
consists of a mixture of boulders, gravels, shingles and alluvial sand deposits
created by itself. Still these river reaches differ considerably from those carrying
sand and silt and flowing through plains. In the later stage, the river flows through
