I85PREP
⌘ K
Maharashtra SSC Water Security Grade study materials
Maharashtra SSC Water Security Grade study resources

Maharashtra SSC Water Security Grade practice questions

One question at a time. Build your Maharashtra SSC Water Security Grade understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Water Resources of Maharashtra: Availability, Distribution and Variability

Which type of rainfall is chiefly responsible for most of Maharashtra's annual precipitation?

  1. Cyclonic rainfall from Bay of Bengal depressions
  2. Orographic rainfall from the Western Ghats Correct answer.
  3. Convectional rainfall from local heating
  4. Frontal rainfall from polar air masses

Explanation

Moist winds from the Arabian Sea are forced to rise over the Western Ghats, cooling and condensing to give heavy orographic rain on the windward slopes. This rain-shadow mechanism explains why the Ghats crest and Konkan get far more rain than the Deccan plateau to the east.

Question 2Water Resources of Maharashtra: Availability, Distribution and Variability

The rain-shadow region lying east of the Western Ghats in Maharashtra is best described by which term?

  1. Tapi flood plain
  2. Deccan rain-shadow belt Correct answer.
  3. Vidarbha plateau
  4. Konkan coastal strip

Explanation

As air descends the eastern side of the Ghats it warms and dries, creating a leeward rain-shadow belt over the Deccan plateau districts. Rainfall here is markedly lower than on the Ghats crest and Konkan coast.

Question 3Water Resources of Maharashtra: Availability, Distribution and Variability

Which of these Maharashtra rivers is a west-flowing river draining directly into the Arabian Sea?

  1. Godavari
  2. Tapi Correct answer.
  3. Wardha
  4. Krishna

Explanation

The Tapi rises in the Betul area and flows west through a rift valley into the Arabian Sea. Most of Maharashtra's other large rivers, such as the Godavari and Krishna systems, flow east towards the Bay of Bengal.

Question 4Water Resources of Maharashtra: Availability, Distribution and Variability

Which river is the longest and largest river system originating within Maharashtra?

  1. Narmada
  2. Krishna
  3. Godavari Correct answer.
  4. Tapi

Explanation

The Godavari rises near Trimbakeshwar in Nashik district and is the largest river system originating in Maharashtra, draining much of the Deccan plateau before reaching the Bay of Bengal. Its major tributaries include the Purna, Pravara, Mula-Mutha, Manjra and Wardha.

Question 5Water Resources of Maharashtra: Availability, Distribution and Variability

Maharashtra's climate is best classified as which type?

  1. Hot desert throughout the year
  2. Mediterranean with summer drought
  3. Humid continental with cold winters
  4. Tropical monsoon with dry winters Correct answer.

Explanation

Maharashtra has a tropical monsoon climate in which the year divides into a hot dry season, a rainy monsoon season and a cooler dry winter. Rainfall is strongly seasonal and concentrated in the south-west monsoon months.

Question 6Water Resources of Maharashtra: Availability, Distribution and Variability

The Konkan coastal strip of Maharashtra lies between which two features?

  1. The Deccan traps and the Godavari basin
  2. The Arabian Sea and the Western Ghats Correct answer.
  3. The Sahyadri crest and the Tapi rift
  4. The Satpura range and the Narmada valley

Explanation

The Konkan is the narrow coastal lowland bounded by the Arabian Sea on the west and the Western Ghats (Sahyadri) on the east. It receives very heavy orographic rainfall and is drained by short, fast west-flowing rivers.

Question 7Water Resources of Maharashtra: Availability, Distribution and Variability

Which of the following is a major source of surface water storage for irrigation in Maharashtra?

  1. Coastal desalination plants
  2. Thar desert aquifers
  3. Himalayan glacier melt
  4. Koyna, Jayakwadi and Ujani reservoirs Correct answer.

Explanation

Maharashtra relies heavily on medium and major reservoirs such as Koyna, Jayakwadi on the Godavari and Ujani on the Bhima for irrigation and water supply. These store monsoon runoff for use in the dry months.

Question 8Water Resources of Maharashtra: Availability, Distribution and Variability

The Bhima river, an important tributary in Maharashtra, belongs to which larger river basin?

  1. Tapi basin
  2. Krishna basin Correct answer.
  3. Godavari basin
  4. Narmada basin

Explanation

The Bhima rises in the Western Ghats near Bhimashankar and flows south-east to join the Krishna. It is therefore part of the Krishna basin, and the Ujani dam on it is a major storage project.

Question 9Water Resources of Maharashtra: Availability, Distribution and Variability

Why does the Konkan coast of Maharashtra receive far more annual rainfall than the districts of the Deccan plateau?

  1. Moisture-laden winds rise over the Ghats on the windward side Correct answer.
  2. It receives winter rain from western disturbances
  3. It lies closer to the equator than the plateau
  4. It has more lakes and reservoirs than the plateau

Explanation

Arabian Sea winds strike the windward western slopes of the Western Ghats and are forced upward, cooling and releasing heavy rain. By the time the air crosses the crest it has lost most moisture, so the leeward plateau stays comparatively dry.

Question 10Water Resources of Maharashtra: Availability, Distribution and Variability

A farmer in a rain-shadow district of Maharashtra wants to reduce drought risk. Which measure most directly addresses variability of rainfall?

  1. Growing a single water-intensive cash crop
  2. Clearing vegetation from the catchment
  3. Increasing flood irrigation frequency
  4. Building farm ponds and adopting watershed treatment Correct answer.

Explanation

Farm ponds and watershed treatment capture and store monsoon runoff locally, making water available during dry spells. This directly buffers the farmer against erratic rainfall rather than increasing demand on scarce water.

Question 11Water Resources of Maharashtra: Availability, Distribution and Variability

Which statement best explains why Maharashtra experiences frequent water scarcity despite receiving substantial monsoon rainfall?

  1. Rainfall is highly seasonal and unevenly distributed in space Correct answer.
  2. The state has no rivers of significant size
  3. Groundwater is absent in the Deccan traps
  4. Rainfall is evenly spread through the year

Explanation

Most rain falls in a few monsoon months and varies sharply between the wet Ghats and the dry rain-shadow plateau. Storage and distribution infrastructure cannot always bridge this temporal and spatial mismatch, so scarcity occurs even in a high-rainfall state.

Question 12Water Resources of Maharashtra: Availability, Distribution and Variability

The Jayakwadi project is located on which river?

  1. Krishna
  2. Tapi
  3. Godavari Correct answer.
  4. Bhima

Explanation

Jayakwadi, near Paithan in Chhatrapati Sambhajinagar district, is a major dam on the Godavari. It supports irrigation and water supply in the Marathwada region.

Question 13Water Resources of Maharashtra: Availability, Distribution and Variability

In the Deccan trap region of Maharashtra, groundwater is most likely to be found in which setting?

  1. Unweathered massive basalt at depth
  2. Alluvial fans of the eastern plateau
  3. Granite batholiths of the Konkan
  4. Weathered zones and fractured lava flows Correct answer.

Explanation

Basalt itself has low primary porosity, so groundwater in the Deccan traps occurs mainly in weathered mantle and in fractured or vesicular flow contacts. Wells are sited to intersect these secondary openings.

Question 14Water Resources of Maharashtra: Availability, Distribution and Variability

Which factor most strongly determines the direction in which Maharashtra's major rivers flow?

  1. The overall eastward tilt of the Deccan plateau Correct answer.
  2. The distribution of urban population
  3. The prevailing wind direction in summer
  4. The location of coastal desalination plants

Explanation

The Deccan plateau slopes gently eastward, so the Godavari, Krishna and their tributaries flow east to the Bay of Bengal. The Tapi and Narmada occupy west-flowing rift valleys, which are exceptions to the general tilt.

Question 15Water Resources of Maharashtra: Availability, Distribution and Variability

A district receives about 600 mm of annual rainfall concentrated in three monsoon months. Which cropping strategy best adapts to this variability?

  1. Drought-tolerant crops with protective irrigation and moisture conservation Correct answer.
  2. Year-round sugarcane with heavy canal irrigation
  3. Continuous paddy cultivation across the year
  4. Cultivation of water-intensive horticulture without storage

Explanation

Where rainfall is low and seasonal, drought-tolerant crops combined with protective irrigation and moisture conservation reduce risk. This matches water availability to crop demand instead of relying on continuous heavy irrigation.

Question 16Water Resources of Maharashtra: Availability, Distribution and Variability

Which of the following best describes the role of the Western Ghats in Maharashtra's water resources?

  1. They act as a major catchment and water tower feeding west- and east-flowing rivers Correct answer.
  2. They store groundwater in limestone caves
  3. They block the monsoon and reduce rainfall across the state
  4. They divert the Godavari towards the Arabian Sea

Explanation

The Western Ghats intercept heavy monsoon rain and form the catchment for numerous rivers, including the sources of the Godavari, Krishna and Bhima and the short Konkan streams. They thus function as the state's principal water tower.

Question 17Water Resources of Maharashtra: Availability, Distribution and Variability

Which of these is a west-flowing river of the Konkan that drains directly into the Arabian Sea?

  1. Manjra
  2. Purna
  3. Indravati
  4. Ulhas Correct answer.

Explanation

The Ulhas is a short west-flowing Konkan river that reaches the Arabian Sea near Mumbai. Konkan rivers are steep and fast because they descend quickly from the Ghats to the coast.

Question 18Water Resources of Maharashtra: Availability, Distribution and Variability

Inter-basin transfer of water within Maharashtra is primarily intended to address which problem?

  1. Excess rainfall along the Konkan coast
  2. Decline of groundwater in the Konkan
  3. Loss of soil fertility in Vidarbha
  4. Spatial mismatch between water-surplus and water-deficit regions Correct answer.

Explanation

Water is abundant in the Ghats and Konkan but scarce in the rain-shadow plateau and parts of Marathwada. Inter-basin transfer moves stored surplus water to deficit regions to reduce spatial disparity.

Question 19Water Resources of Maharashtra: Availability, Distribution and Variability

Which combination of monsoon behaviour most directly causes a drought year in Maharashtra?

  1. Late onset combined with long dry spells during the monsoon Correct answer.
  2. Above-normal winter rainfall
  3. Early onset with evenly spaced rainfall
  4. High humidity in the pre-monsoon period

Explanation

A delayed monsoon followed by prolonged dry spells within the season leaves insufficient soil moisture and reservoir inflow for kharif crops. This intra-seasonal variability, not just the seasonal total, drives agricultural drought.

Question 20Water Resources of Maharashtra: Availability, Distribution and Variability

Why is the Tapi described as flowing in a rift valley?

  1. It was artificially excavated as a canal
  2. It occupies a down-faulted trough between the Satpura and Ajanta ranges Correct answer.
  3. It follows a coastal plain formed by sea-level rise
  4. It flows through a glacial valley carved in the Pleistocene

Explanation

The Tapi flows through a linear down-faulted depression between the Satpura range to the north and the Ajanta range to the south. This structural trough explains its straight west-flowing course.

Question 21Water Resources of Maharashtra: Availability, Distribution and Variability

A reservoir in the rain-shadow plateau shows large seasonal storage fluctuation but little annual carry-over. Which inference is most defensible?

  1. The reservoir is fed by a glacier
  2. The catchment receives highly seasonal rainfall with limited base flow Correct answer.
  3. Groundwater recharge in the catchment is uniformly high
  4. The catchment is fed by perennial snowmelt

Explanation

Strong seasonal filling followed by depletion indicates that inflow depends almost entirely on monsoon runoff, with little dry-season base flow to sustain storage. This is typical of hard-rock catchments in the rain-shadow belt.

Question 22Water Resources of Maharashtra: Availability, Distribution and Variability

Which statement best explains why the Konkan's short rivers have limited water-storage potential compared with the Godavari?

  1. They have steep gradients and small catchments, so runoff reaches the sea quickly Correct answer.
  2. They flow too slowly to be dammed
  3. Their catchments lie in a semi-arid zone
  4. They carry no monsoon runoff

Explanation

Konkan rivers descend steeply over a short distance from the Ghats to the sea, so water moves rapidly offshore and the small catchments offer few large dam sites. Longer plateau rivers such as the Godavari allow larger storage reservoirs.

Question 23Water Resources of Maharashtra: Availability, Distribution and Variability

In a Deccan trap watershed, which intervention would most improve dry-season base flow in streams?

  1. Deepening channels to drain the aquifer
  2. Removing vegetation from the catchment
  3. Constructing check dams and recharge trenches along drainage lines Correct answer.
  4. Paving the catchment to speed runoff

Explanation

Check dams and recharge trenches slow runoff and increase infiltration into weathered and fractured basalt, raising the water table. The stored groundwater is then released gradually, sustaining stream flow in the dry season.

Question 24Water Resources of Maharashtra: Availability, Distribution and Variability

Which pairing of a Maharashtra water project with its river is correct?

  1. Bhatsa dam on the Krishna
  2. Ujani dam on the Bhima Correct answer.
  3. Koyna dam on the Godavari
  4. Jayakwadi dam on the Tapi

Explanation

Ujani dam is built across the Bhima river in Solapur district and is one of the largest reservoirs in the state. Correctly linking a project to its river requires knowing the basin in which the dam lies.

Question 25Water Resources of Maharashtra: Availability, Distribution and Variability

Comparing two districts, one on the Ghats crest and one in the leeward plateau, which pattern of rainfall and runoff is expected?

  1. The plateau district has higher rainfall but lower runoff
  2. The Ghats district has lower rainfall and higher runoff
  3. The Ghats district has higher rainfall and higher runoff Correct answer.
  4. Both districts have similar rainfall and runoff

Explanation

Orographic lifting makes the windward Ghats district wetter, and greater rainfall combined with steep slopes produces more runoff. The leeward plateau district receives less rain and has gentler slopes, so runoff is lower.

Question 26Water Resources of Maharashtra: Availability, Distribution and Variability

Which soil type covers most of the Deccan plateau districts of Maharashtra and strongly influences how rainfall is stored and lost as runoff?

  1. Alluvial soil deposited by the Godavari
  2. Black cotton soil formed from weathered basalt Correct answer.
  3. Laterite soil developed on the Konkan coast
  4. Saline coastal soil of the tidal creeks

Explanation

Most plateau districts are underlain by Deccan trap basalt, which weathers into deep black cotton soil. This clay-rich soil swells when wet and cracks when dry, so infiltration and storage behave very differently from sandy or lateritic soils. Knowing the parent rock and soil helps explain runoff and groundwater recharge patterns.

Question 27Water Resources of Maharashtra: Availability, Distribution and Variability

In Maharashtra's statistical reporting, a year is commonly treated as a meteorological drought year when seasonal rainfall departs below normal by more than which threshold?

  1. About 10 percent
  2. About 50 percent
  3. About 75 percent
  4. About 25 percent Correct answer.

Explanation

Indian meteorological practice classifies a season as deficient when rainfall falls more than about 25 percent below the long-period normal. Smaller shortfalls are treated as below normal rather than drought. This threshold matters for declaring scarcity and triggering relief measures in Maharashtra's districts.

Question 28Water Resources of Maharashtra: Availability, Distribution and Variability

A village on the leeward side of the Western Ghats in Maharashtra receives modest rainfall but sits at the head of a long basalt watershed. Which combination of measures would most reliably improve its dry-season water availability?

  1. Deepening the existing open well and installing a higher-capacity pump
  2. Constructing an earthen bund across the main stream to store the monsoon flow
  3. Building check dams and contour trenches to slow runoff and recharge the aquifer Correct answer.
  4. Lining the village canal so that seepage losses are eliminated

Explanation

In hard-rock basalt terrain, water must be held on the surface long enough to infiltrate and move into fractures. Contour trenches and check dams spread and detain runoff, raising recharge and supporting later base flow. Pumping or canal lining redistributes existing water without adding storage, and a single bund stores water only where it stands.

Question 29Water Resources of Maharashtra: Availability, Distribution and Variability

Two neighbouring talukas have the same mean annual rainfall, but one has thin soil on steep slopes and the other has deep soil on gentle slopes. Which outcome is most consistent with watershed hydrology?

  1. The steep, thin-soil taluka will have higher infiltration and steadier base flow
  2. The gentle, deep-soil taluka will produce more surface runoff and less recharge
  3. The steep, thin-soil taluka will generate faster runoff and flashier stream flow Correct answer.
  4. Both talukas will show identical runoff because rainfall totals are equal

Explanation

Slope and soil depth govern how much rain infiltrates versus runs off. Steep slopes with shallow soil shed water quickly, producing high peak flows and low dry-season base flow. Gentle slopes with deep soil allow more infiltration and slower release, so equal rainfall does not mean equal runoff.

Question 30Water Resources of Maharashtra: Availability, Distribution and Variability

Maharashtra's major east-flowing rivers and its west-flowing Konkan rivers differ in a systematic way that shapes water management. Which statement best captures that difference?

  1. West-flowing rivers carry more annual flow because their basins are far larger
  2. Both sets of rivers have similar lengths because they rise on the same crest line
  3. East-flowing rivers are short and steep, while west-flowing rivers are long and gently graded
  4. East-flowing rivers cross the broad plateau with long courses, while west-flowing rivers descend steeply over a short distance Correct answer.

Explanation

Rivers rising near the Ghats crest and turning east traverse the wide Deccan plateau, giving long courses and large catchments. Those draining west drop rapidly down the Ghats escarpment to the Arabian Sea over short distances. This contrast explains why plateau rivers support large storage projects while Konkan rivers offer limited storage but high energy and flood potential.

Question 31Hydrological Cycle, Watersheds and Catchment Management

In the hydrological cycle, which process returns water vapour from plants directly to the atmosphere?

  1. Percolation
  2. Condensation
  3. Transpiration Correct answer.
  4. Infiltration

Explanation

Transpiration is the release of water vapour through stomata in leaves, and together with evaporation from soil it forms evapotranspiration, a major pathway of water loss from a catchment. Infiltration and percolation move liquid water downward into soil and rock, while condensation changes vapour back into liquid droplets.

Question 32Hydrological Cycle, Watersheds and Catchment Management

A catchment area receives 1200 mm of rainfall in a year and records 480 mm of runoff at its outlet. Using the runoff coefficient, how much of the rainfall becomes streamflow?

  1. 0.48
  2. 0.60
  3. 0.25
  4. 0.40 Correct answer.

Explanation

The runoff coefficient is runoff divided by rainfall, so 480 mm divided by 1200 mm gives 0.40. This means about 40 per cent of rainfall leaves the catchment as streamflow, while the remainder is lost to evapotranspiration, storage and deep recharge.

Question 33Hydrological Cycle, Watersheds and Catchment Management

Which term describes the boundary line that separates two adjacent drainage basins?

  1. Aquifer
  2. Delta
  3. Water divide Correct answer.
  4. Flood plain

Explanation

A water divide, also called a watershed divide or drainage divide, is the ridge or high ground along which rainfall splits and flows into two different river systems. Flood plains and deltas are landforms within a basin, and an aquifer is a water-bearing rock formation.

Question 34Hydrological Cycle, Watersheds and Catchment Management

Which soil property most directly increases the infiltration capacity of a catchment surface?

  1. High clay content
  2. Steep surface slope
  3. Compacted and bare surface
  4. Good aggregate structure with macropores Correct answer.

Explanation

Well-aggregated soil with continuous macropores allows water to enter quickly, raising infiltration capacity and reducing surface runoff. Clay-rich, compacted or steeply sloping surfaces instead promote lower infiltration and more overland flow.

Question 35Hydrological Cycle, Watersheds and Catchment Management

In a watershed management plan, which measure is a structural soil and water conservation practice?

  1. Community awareness campaign
  2. Grazing regulation
  3. Crop rotation scheduling
  4. Contour trenching Correct answer.

Explanation

Contour trenches are physical structures built across a slope to trap runoff and allow it to infiltrate, so they are structural conservation measures. Crop rotation, grazing rules and awareness campaigns are non-structural management practices.

Question 36Hydrological Cycle, Watersheds and Catchment Management

Which component of the hydrological cycle accounts for the largest return of water from land surfaces to the atmosphere?

  1. Snowmelt runoff
  2. Groundwater discharge to the sea
  3. Evapotranspiration Correct answer.
  4. Capillary rise

Explanation

On a global scale, evapotranspiration is the dominant pathway by which water returns from land to the atmosphere, combining evaporation from soil and water bodies with plant transpiration. Groundwater discharge, snowmelt and capillary rise redistribute water but do not dominate the atmospheric return.

Question 37Hydrological Cycle, Watersheds and Catchment Management

Which unit is conventionally used to express the area of a large river catchment in Maharashtra?

  1. Square kilometres Correct answer.
  2. Hectares per year
  3. Millimetres of mercury
  4. Cubic metres per second

Explanation

Catchment area is a two-dimensional extent and is expressed in square kilometres, or hectares for small watersheds. Millimetres of mercury measure pressure, cubic metres per second measure discharge, and hectares per year is not a valid area unit.

Question 38Hydrological Cycle, Watersheds and Catchment Management

A catchment of 50 square kilometres receives 800 mm of rain in a season. What is the total volume of rainfall received, in million cubic metres?

  1. 400
  2. 4000
  3. 40 Correct answer.
  4. 4

Explanation

Area is 50 square kilometres, which equals 50 million square metres, and depth is 0.8 metre, so volume is 50 million multiplied by 0.8, giving 40 million cubic metres. Converting units consistently before multiplying prevents order-of-magnitude errors.

Question 39Hydrological Cycle, Watersheds and Catchment Management

Which factor most strongly increases the peak discharge of a catchment for a storm of given depth?

  1. A shorter time of concentration Correct answer.
  2. A gentler channel slope
  3. A deeper permanent soil moisture deficit
  4. A larger area of forest cover

Explanation

A shorter time of concentration means runoff from different parts of the catchment reaches the outlet more quickly and concentrates, raising peak discharge. Forest cover, soil moisture deficit and gentle slopes all tend to delay or reduce the peak.

Question 40Hydrological Cycle, Watersheds and Catchment Management

What is the main purpose of a check dam built across a seasonal stream in a watershed?

  1. To increase the velocity of flood flows
  2. To measure rainfall intensity
  3. To store and recharge groundwater while slowing runoff Correct answer.
  4. To treat domestic sewage

Explanation

A check dam is a small barrier across a seasonal stream that slows runoff, stores water for local use and promotes infiltration so that groundwater is recharged. It does not measure rainfall, accelerate floods or treat sewage.

Question 41Hydrological Cycle, Watersheds and Catchment Management

Which statement correctly distinguishes a watershed from a river basin?

  1. A watershed is a smaller drainage unit that may nest within a river basin Correct answer.
  2. A river basin has no defined boundary
  3. A watershed is always larger than a river basin
  4. A watershed contains no streams

Explanation

Both terms describe areas draining to a common point, but a watershed is typically a smaller unit that can be nested within a larger river basin draining to the sea. Boundaries are defined by divides in both cases, and both contain streams.

Question 42Hydrological Cycle, Watersheds and Catchment Management

Which practice best reduces soil erosion on a steep agricultural slope within a watershed?

  1. Removing all vegetation before sowing
  2. Increasing plot size by levelling terraces
  3. Ploughing up and down the slope
  4. Planting along contour lines with vegetative strips Correct answer.

Explanation

Contour planting with vegetative strips slows overland flow, traps sediment and increases infiltration, so erosion is reduced. Ploughing up and down the slope creates channels for fast runoff, while bare soil and large levelled plots expose soil to erosion.

Question 43Hydrological Cycle, Watersheds and Catchment Management

In a hydrograph, what does the rising limb represent?

  1. The period of increasing discharge after rainfall begins Correct answer.
  2. The recession of flow after the peak
  3. The period of steady baseflow before a storm
  4. The groundwater level at the outlet

Explanation

The rising limb shows discharge increasing as rainfall reaches the stream through overland flow and quick subsurface pathways. Baseflow precedes the storm, the recession follows the peak, and groundwater level is a separate variable.

Question 44Hydrological Cycle, Watersheds and Catchment Management

Which condition would most likely cause a catchment to have a high baseflow index?

  1. Steep slopes with sparse vegetation
  2. Rapid urbanisation with paved surfaces
  3. Extensive impermeable rock with thin soil
  4. Large, permeable aquifer storage feeding the stream Correct answer.

Explanation

A high baseflow index means a large share of streamflow comes from stored groundwater, which requires permeable formations that hold and slowly release water. Impermeable rock, paving and steep bare slopes instead produce flashy quickflow and low baseflow.

Question 45Hydrological Cycle, Watersheds and Catchment Management

Which method is used to estimate runoff from a small ungauged watershed when only rainfall records are available?

  1. Rational method using rainfall intensity and area Correct answer.
  2. Float method at the outlet
  3. Direct current-meter gauging
  4. Salt dilution gauging

Explanation

The rational method estimates peak runoff from rainfall intensity, catchment area and a runoff coefficient, and is suited to small ungauged catchments. Current-meter, salt dilution and float methods all require measurements at the stream itself.

Question 46Hydrological Cycle, Watersheds and Catchment Management

What is the primary hydrological effect of urbanisation on a catchment?

  1. Increased impervious area and higher, faster peak flows Correct answer.
  2. Increased infiltration and lower peak flows
  3. Increased evapotranspiration and reduced runoff volume
  4. Increased groundwater recharge and stable baseflow

Explanation

Urbanisation replaces permeable surfaces with roofs and roads, so infiltration falls and a larger share of rainfall becomes quick surface runoff, producing higher and earlier peaks. Recharge and evapotranspiration generally decline as a result.

Question 47Hydrological Cycle, Watersheds and Catchment Management

Which of these is a non-structural measure for watershed development?

  1. Framing rules for groundwater use Correct answer.
  2. Laying sub-surface dykes
  3. Building contour bunds
  4. Constructing farm ponds

Explanation

Framing rules for groundwater use is a regulatory, non-structural measure that shapes behaviour without building anything. Contour bunds, farm ponds and sub-surface dykes are engineered structures that modify water movement physically.

Question 48Hydrological Cycle, Watersheds and Catchment Management

A stream hydrograph shows a sharp peak occurring only two hours after heavy rain on a small catchment. Which explanation is most consistent with this response?

  1. The catchment has large floodplain storage
  2. The catchment has extensive snow cover
  3. The catchment has compacted surfaces and a short time of concentration Correct answer.
  4. The catchment has deep sandy soils and dense forest

Explanation

A rapid, sharp peak indicates fast runoff delivery, which occurs where surfaces are compacted or impervious and where the time of concentration is short. Deep sandy soils, floodplain storage and snow cover all delay and flatten the response.

Question 49Hydrological Cycle, Watersheds and Catchment Management

Which statement about groundwater and surface water interaction in a watershed is correct?

  1. Streams lose water where the water table is above the stream bed
  2. Groundwater never exchanges with streams
  3. Streams gain water where the water table is above the stream bed Correct answer.
  4. Baseflow is unrelated to aquifer storage

Explanation

A gaining stream receives groundwater discharge because the water table stands higher than the stream stage, sustaining baseflow between storms. Where the water table lies below the stream bed, the stream loses water to the aquifer instead.

Question 50Hydrological Cycle, Watersheds and Catchment Management

Which combination of catchment characteristics would produce the highest flood peak for a given storm?

  1. Small area, steep slope, impervious surface Correct answer.
  2. Large area, gentle slope, extensive wetlands
  3. Small area, flat surface, deep sandy soil
  4. Large area, gentle slope, dense forest

Explanation

A small, steep, impervious catchment delivers rainfall rapidly to the outlet with little storage or infiltration, so the flood peak is high and early. Large, gentle, forested, sandy or wetland catchments all attenuate and delay runoff.