Drainage Pattern & Morphometric analyses of drainage basins. In geomorphology, the patterns formed by the streams, rivers, and lakes in a particular drainage basin. Also known as drainage systems or river systems. According to the configuration of the channels, drainage systems can fall into one of several categories known as drainage patterns. Drainage patterns depend on the topography & geology of the land. Drainage basins: The total land surface drained by a system of stream leading to the same outflow. Drainage system: The stream, tributaries, and other bodies of water by which a region is called drained. Drainage divide: The boundary between adjacent drainage basins. An area of land drained by a river and its tributaries. It is also called the Catchment area. Any precipitation which falls into the basin is collected and drains into the main river or its tributaries by runoff, throughflow or groundwater flow. Its boundary marked by a ridge of high land called watershed. Drainage basins have one main stream and many tributaries. Each tributaries of main stream forms sub-drainage basin.

1. DRAINAGE PATTERN & MORPHOMETRIC
ANALYSES OF DRAINAGE BASINS.
Ujjaval Patel
GEL 410

2. DRAINAGE BASIN
• In geomorphology, the patterns formed by the streams, rivers, and lakes in a
particular drainage basin. Also known as drainage systems or river systems.
• According to the configuration of the channels, drainage systems can fall into one of
several categories known as drainage patterns. Drainage patterns depend on
the topography & geology of the land.
• Drainage basins: The total land surface drained by a system of stream leading to the
same outflow.
• Drainage system: The stream, tributaries, and other bodies of water by which a
region is called drained.
• Drainage divide: The boundary between adjacent drainage basins.

3. • An area of land drained by a river and its tributaries.
• It is also called the Catchment area.
• Any precipitation which falls into the basin is collected and drains into the main river or its
tributaries by runoff, throughflow or groundwater flow.
• Its boundary marked by a ridge of high land called watershed.
• Drainage basins have one main stream and many tributaries.
• Each tributaries of main stream forms sub-drainage basin.

7. DRAINAGE BASIN: A SYSTEMS APPROACH
• A number of factors influence input, output, and transport of sediment and
water in the drainage basin.
• Such factor include topography, soil type, bedrock type, climate, and
vegetation cover.
• These factor also influence the nature of the pattern of stream channels.

8. TYPES OF DRAINAGE SYSTEM
• Drainage systems can fall into one of several categories, depending on the
topography and geology of the land:
• Dendritic drainage pattern.
• Parallel drainage pattern.
• Trellis drainage pattern.
• Rectangular drainage system
• Radial drainage system
• Deranged drainage system
• Annular drainage pattern

9. DENDRITIC DRAINAGE SYSTEM
• Comes from the Greek word meaning tree.
• Most common types
• Many contributing streams (like twigs on a tree)
• They then join into the main stream or river.
• They form following the slope or gradient of the terrain they are in.

10. PARALLEL DRAINAGE SYSTEM
• Pattern of rivers caused by steep slopes with some relief (flat parts)
• Due to the steep slopes, the streams are swift and straight, with very few
tributaries (branches), and all flow in the same direction.

11. TRELLIS DRAINAGE SYSTEM
• The geometry of a trellis drainage system is similar to that of a common
garden trellis used to grow vines.
• As the river flows along a valley, smaller tributaries feed into it from the
steep slopes on the sides of mountains.
• These tributaries enter the main river at approximately 90 degree angles,
causing a trellis-like appearance of the drainage system.

12. RADIAL DRAINAGE SYSTEM
• Streams radiate outwards from a central high point.
• Volcanos usually display excellent radial drainage.
• Will also form on domes or laccoliths.
• This creates a radial pattern (think of a pizza or an orange).

13. ANNULAR DRAINAGE PATTERN
• In an annular drainage pattern streams follow a roughly circular path,
creating a ring like pattern.
• This is because the rock is weak, which means that it is very porous,
allowing a lot of water to flow into it.

15. DRAINAGE BASIN MORPHOMETRY
• Morphometric analysis is refers as the quantitative evaluation of form
characteristics of the earth surface and any landform unit.
• This is the most common technique in basin analysis, as morphometry
form an ideal areal unit for interpretation and analysis of fluvial originated
landforms where they exhibits and example of open systems of operation.
• The composition of the stream system of a drainage basin in expressed
quantitatively with stream order, drainage density, bifurcation ration and
stream length ratio
• It incorporates quantitative study of the various components such as,
stream segments, basin length, basin parameters, basin area, altitude,
volume, slope, profiles of the land which indicates the nature of
development of the basin.

16. • Stream Order (U)
 Stream Order (U) There are four different system of ordering streams that are
available Gravelius (1914), Horton (1945), Strahler (1952) and Schideggar
(1970). Strahler’s system, which is a slightly modified of Hortons system, has
been followed because of its simplicity. Where the smallest, unbranched
fingertip streams are designated as 1st order, the confluence of two 1st order
channels give a channel segments of 2nd order, two 2nd order streams join to
form a segment of 3rd order and so on. When two channel of different order join
then the higher order is maintained. The trunk stream is the stream segment
of highest order.
• Stream Number (Nu)
 The total number of stream segments present in each order is the stream
number (Nu). Nu is number of streams of order u.

17. • Stream Length (Lu)
 The total length of individual stream segments of each order is the stream
length of that order. Stream length measures the average (or mean) length of a
stream in each orders, and is calculated by dividing the total length of all
streams in a particular order by the number of streams in that order. The
stream length in each order increases exponentially with increasing stream
order.
• Bifurcation Ratio (Rb)
 The bifurcation ratio is the ratio between the number of streams in one order
and in the next. It is calculated by dividing the number of streams in the lower
by the number in the higher of the two orders; the bifurcation ration of large
basins is generally the average of the bifurcation rations of the stream orders
within it.
𝑅𝑏 = 𝑁𝑢
Nu+1

18. • Drainage Density (Dd)
• Drainage density has long been recognised as topographic characteristic of fundamental
significance. This arise from that fact that drainage density is sensitive parameter
which in many ways provides the link between the form attributes of the basin and the
processes operating along stream course (Gregory and Welling, 1973). It reflects the
landuse and affects infiltration and the basin response time between precipitation and
discharge. It is also of geomorphological interest particularly for the development of
slopes. Drainage basin with high Dd indicates that a large proportion of the
precipitation runs off. On the other hand, a low drainage density indicates the most
rainfall infiltrates the ground and few channels are required to carry the runoff (Roger,
1971). Dd is considered to be an important index; it is expresses as the ratio of the total
sum of all channel segments within a basin to the basin area i.e., the length of streams
per unit of drainage density. It is a dimension inverse of length (Horton, 1932). Dd is a
measure of the texture of the network, and indicates the balance between the erosive
power of overland flow and the resistance of surface soils and rocks. The factors affecting
drainage density include geology and density of vegetation. The vegetation density
influenced drainage density by binding the surface layer and slows down the rate of
overland flow, and stores some of the water for short periods of time. The effect of
lithology on drainage density is marked. Permeable rocks with a high infiltration rate
reduce overland flow, and consequently drainage density is low.

19. REFERENCES
• http://shodhganga.inflibnet.ac.in/bitstream/10603/5456/9/09_chapter%205.p
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