MPSC 2024 Prelims Q24: Which type of drainage pattern is found in Maharashtra ?

Q: What is the answer to MPSC 2024 Prelims Q24?

(4). Correct — option (4), All of the above: dendritic, parallel, indefinite and trellis patterns are all met with in Maharashtra. The question is not asking which single pattern characterises the state; it is asking which of the four occur within it, and a state that runs from a narrow coastal strip through a steep north-south mountain wall onto a wide lava plateau has room for all of them. Take them in turn. The dendritic pattern — a trunk stream with tributaries joining it at acute angles like the branches of a tree — develops where the underlying rock offers roughly uniform resistance and no structural line steers the water. That is the ordinary condition over most of the Deccan basalt, and the great east-flowing plateau drainage of the Godavari and Bhima basins takes this branching form. The parallel pattern — a set of streams running side by side in the same direction, joining nothing until they reach base level — develops where the land has a strong uniform slope. The western face of the Sahyadri gives exactly that: the short, swift Konkan rivers drop from the crest to the Arabian Sea down a single steep gradient in a series of roughly parallel courses. The trellis pattern — tributaries meeting the main stream at close to right angles, giving a rectangular, grid-like network — develops where the rock is not uniform but banded, so that streams cut along the weaker bands and cross the harder ones only at gaps; the Deccan lava pile is made of stacked flows of differing hardness and is cut by joints and lineaments, and where those exert control the drainage takes on this angular arrangement. The indefinite pattern is the residual class: drainage that shows no consistent geometry at all, because relief is irregular and neither slope nor rock structure dominates strongly enough to impose a shape. Each of the three partial options excludes one pattern that does occur, so only option (4) is defensible.

MPSC 2024 Prelims Paper-I · Question 24 of 100

Maharashtra Gazetted Civil Services Combined Preliminary Examination 2024, held 1 December 2024. Transcribed from the commission's own booklet (संच A); answer as per the official MPSC final answer key.

Which type of drainage pattern is found in Maharashtra ? (a) Dendritic (b) Parallel (c) Indefinite (d) Trellis Answer options :

(1)(a), (b) and (c)
(2)(b), (c) and (d)
(3)(a), (c) and (d)
(4)All of the above

Answer

(4)

Why

Correct — option (4), All of the above: dendritic, parallel, indefinite and trellis patterns are all met with in Maharashtra. The question is not asking which single pattern characterises the state; it is asking which of the four occur within it, and a state that runs from a narrow coastal strip through a steep north-south mountain wall onto a wide lava plateau has room for all of them. Take them in turn. The dendritic pattern — a trunk stream with tributaries joining it at acute angles like the branches of a tree — develops where the underlying rock offers roughly uniform resistance and no structural line steers the water. That is the ordinary condition over most of the Deccan basalt, and the great east-flowing plateau drainage of the Godavari and Bhima basins takes this branching form. The parallel pattern — a set of streams running side by side in the same direction, joining nothing until they reach base level — develops where the land has a strong uniform slope. The western face of the Sahyadri gives exactly that: the short, swift Konkan rivers drop from the crest to the Arabian Sea down a single steep gradient in a series of roughly parallel courses. The trellis pattern — tributaries meeting the main stream at close to right angles, giving a rectangular, grid-like network — develops where the rock is not uniform but banded, so that streams cut along the weaker bands and cross the harder ones only at gaps; the Deccan lava pile is made of stacked flows of differing hardness and is cut by joints and lineaments, and where those exert control the drainage takes on this angular arrangement. The indefinite pattern is the residual class: drainage that shows no consistent geometry at all, because relief is irregular and neither slope nor rock structure dominates strongly enough to impose a shape. Each of the three partial options excludes one pattern that does occur, so only option (4) is defensible.

Why the others are wrong

(1)(a), (b) and (c) — This option accepts dendritic, parallel and indefinite drainage but excludes (d) the trellis pattern. The exclusion is the error. A trellis network forms wherever alternating resistant and less resistant bands, or a set of joints and structural lineaments, force tributaries to run along the weak lines and meet the master stream at nearly right angles — and the Deccan basalt of Maharashtra is a stack of many separate lava flows of unequal hardness, cut by joints, which is precisely the kind of banded, structurally controlled ground that produces angular drainage where the control is strong.
(2)(b), (c) and (d) — This option drops (a) the dendritic pattern, which is the least defensible omission of the three. Dendritic drainage is the default form a river network takes when the bedrock is broadly uniform and no structure steers it, and it is the commonest pattern in Maharashtra, shown by the long east-flowing plateau rivers of the Godavari and Bhima basins across the Deccan lava country. An answer that admits the specialised patterns while excluding the general one has the geography inverted.
(3)(a), (c) and (d) — This option drops (b) the parallel pattern, which is the one the state's relief makes most obvious. West of the Sahyadri crest the land falls steeply to the Arabian Sea over a short distance, and the Konkan rivers respond to that single dominant slope by running side by side in the same direction, short and swift, without converging on a common trunk before they reach the sea. A uniform steep slope is the textbook condition for parallel drainage, and Maharashtra's western scarp supplies it along the state's whole coastline.

Concept

A drainage pattern is the plan-view arrangement a river and its tributaries take, and it is read as evidence of what controlled the water as the network cut down. Four controls matter: the direction and steepness of the initial slope, the uniformity of the rock, the presence of structural lines such as joints and faults, and the shape of the relief. Dendritic patterns record the absence of structural control — uniform rock, gentle regional slope, and a tree-like branching network. Parallel patterns record the dominance of a single steep slope, which lines the streams up in the same direction. Trellis patterns record strong structural control by banded rock, producing right-angled junctions and a rectangular grid. Radial patterns record a central high point from which streams run outward, and centripetal patterns the reverse, streams converging into a basin. The residual class the paper calls indefinite covers drainage that fits none of these cleanly, because relief is irregular and no single control is strong enough to shape the network. Because these are responses to conditions rather than fixed properties of a region, one state can display several of them wherever its geology and relief change.

This question rewards a habit rather than a fact: when a stem asks which of several categories are 'found in' a large and physically varied region, the burden is on the candidate to find a reason each category could NOT occur, not to pick the one that occurs most. Maharashtra is a particularly clear case because its physiography changes three times across a short distance — the Konkan coastal lowland, the Sahyadri scarp and the Deccan plateau — and each division supplies a different set of controls. MPSC returns to Maharashtra's physiography and drainage often enough that the state's three-fold physical division is worth holding as a framework onto which patterns, rivers, rainfall and soils can all be hung. The paper prints its four items side by side on one line and then a separate 'Answer options :' header, so the (a) to (d) list here is a menu of patterns rather than a list of statements to be judged true or false.

Key facts

A dendritic pattern is a tree-like branching network with tributaries joining at acute angles; it forms on rock of roughly uniform resistance where no structural line steers the drainage.
A parallel pattern is a set of streams running side by side in the same direction and forms where a single strong uniform slope dominates, as on the steep western face of the Sahyadri.
A trellis pattern has tributaries meeting the main stream at nearly right angles, producing a grid-like network, and forms where banded rock or structural joints confine streams to the weaker lines.
Maharashtra's physiography divides into the Konkan coastal strip, the Sahyadri or Western Ghats, and the Deccan plateau, and each division supplies a different combination of slope and rock control.
The east-flowing plateau rivers of the Godavari and Bhima basins drain the greater part of Maharashtra across the Deccan basalt, while the short Konkan rivers flow west to the Arabian Sea.

The question asks which patterns OCCUR in Maharashtra, not which one defines it

(a) Dendritic→OCCURS — uniform resistance and no structural steer: the ordinary condition over the Deccan basalt, in the Godavari and Bhima basins

(b) Parallel→OCCURS — one steep uniform slope: the short Konkan rivers dropping side by side from the Sahyadri crest to the sea

(d) Trellis→OCCURS — banded rock: stacked lava flows of differing hardness cut by joints and lineaments give the right-angled, grid-like network

A state running from a coastal strip through a mountain wall onto a lava plateau has room for all four — and each partial option drops one that genuinely occurs.

Study next

The full set of drainage patterns — dendritic, parallel, trellis, rectangular, radial, centripetal, annular and deranged — and the specific control that produces eachMaharashtra's three physiographic divisions and the drainage, rainfall, soil and settlement pattern characteristic of eachThe major river basins of Maharashtra — Godavari, Bhima and Krishna flowing east, the Tapi in the north, and the short west-flowing Konkan riversThe Deccan trap basalt: how it was formed, why it weathers to black regur soil, and how its horizontal flows influence drainage and groundwaterAntecedent, consequent and subsequent drainage, and how the terms describe a river's relationship to the structure it crosses

Common traps

Reading the question as asking for the single dominant pattern of the state, when it asks which patterns are found in it — a physically varied state can show several
Excluding a pattern simply because it is less common or harder to name an example of; rarity within a region is not absence from it
Confusing trellis with rectangular drainage — both give angular junctions, but trellis arises from alternating bands of differing resistance while rectangular drainage follows a joint or fault grid
Assuming the Konkan rivers and the plateau rivers must share a pattern, when the two sides of the Sahyadri differ in slope, length and rock exposure and take different forms

MPSC tests physical geography of Maharashtra as often as it tests the state's history, and drainage patterns appear either as a straight definition question ('which pattern forms where the rock is uniform') or, as here, as a menu of patterns to be included or excluded for a named region. The state-specific version is the harder one, because it needs the candidate to connect an abstract classification to Maharashtra's actual relief. The safe approach is to work from the three physiographic divisions outward: ask what slope and what rock each division offers, and the patterns follow.

Related PYQs

No directly related past PYQ was found.

Practice

practice — not a real PYQ
The short, swift rivers of the Konkan that descend the western face of the Sahyadri to the Arabian Sea characteristically display which drainage pattern ?
- (a)Centripetal
- (b)Parallel
- (c)Annular
- (d)Trellis
Answer(b) Parallel — a single strong and uniform slope, such as the steep western scarp of the Sahyadri, lines streams up side by side in the same direction without letting them converge on a common trunk before reaching base level. Centripetal drainage converges into a basin, annular drainage rings a dome, and trellis drainage requires banded rock producing right-angled junctions.
practice — not a real PYQ
A dendritic drainage pattern is taken as evidence of which of the following conditions ?
- (a)Rock of roughly uniform resistance with no strong structural control
- (b)Alternating bands of hard and soft rock
- (c)A central volcanic dome
- (d)An enclosed inland basin with no outlet
Answer(a) Rock of roughly uniform resistance with no strong structural control — this lets tributaries join the trunk stream at acute angles in a tree-like branching form, which is why dendritic drainage is the default pattern over homogeneous ground. Alternating hard and soft bands produce trellis drainage, a central dome produces radial drainage, and an enclosed basin produces centripetal drainage.