Geographical Techniques MCQ Quiz - Objective Question with Answer for Geographical Techniques - Download Free PDF

The correct answer is: 1 is true and 2 is false

Key Points

• Statement 1: "In an active system of remote sensing, the sensing equipment emits radiation, which is reflected back from the object."  (True)
  • Active remote sensing systems emit their own radiation (e.g., radar, LiDAR).
  • This radiation interacts with the target and is reflected back to the sensor.
  • Examples: RADAR (Radio Detection and Ranging), LiDAR (Light Detection and Ranging).
• Statement 2: "Spectral resolution in remote sensing indicates the frequency of receiving radiations."  (False)
  • Spectral resolution refers to the number and width of spectral bands in which the sensor captures data, not the frequency of receiving radiation.
  • It defines the ability to distinguish different wavelengths (e.g., visible, infrared, microwave).
  • Higher spectral resolution means the sensor can capture finer wavelength differences.

The correct answer is: '1, 2, and 3'.

Key Points

• It is the total length of all streams in a basin divided by the basin area.
  • This statement is correct.
  • Drainage Density (Dd) is defined as the ratio of the total length of streams in a drainage basin to the total area of that basin. It quantifies the extent of channel development in a basin.
  • Mathematically, \( Dd = \frac{\Sigma L}{A} \), where \(\Sigma L \) is the total stream length, and (A) is the basin area.
  • Hence, this statement accurately describes the parameter.
• It is inversely related to soil permeability and vegetation density.
  • This statement is correct.
  • Higher permeability allows for greater infiltration, reducing surface runoff and resulting in lower drainage density.
  • Vegetation reduces runoff by intercepting precipitation and increasing infiltration, which also lowers drainage density.
  • Thus, an inverse relationship exists, validating this statement.
• Higher Dd values indicate a coarser drainage texture.
  • This statement is correct.
  • A higher Drainage Density reflects a dense network of channels, often associated with poorly permeable surfaces and steep slopes, leading to coarser drainage textures.
  • Regions with higher Dd are often prone to rapid surface runoff and erosion.
  • Therefore, this statement aligns with the concept of Dd.
• Lower Dd values are associated with highly dissected terrains.
  • This statement is incorrect.
  • Lower Drainage Density is typically found in less dissected terrains with higher soil permeability, dense vegetation, and gentle slopes.
  • Highly dissected terrains usually show higher Dd due to numerous channels and steeper relief.
  • Hence, this statement does not accurately describe the parameter.

Additional Information

• Drainage Density and its Implications:
  • Low Dd: Indicates well-drained basins with high infiltration and minimal surface runoff.
  • High Dd: Suggests poorly permeable surfaces, steep slopes, and limited vegetation, leading to rapid runoff and erosion.
  • Influencing Factors: Geological structure, soil type, slope, vegetation cover, and rainfall intensity are key factors affecting Dd.

The correct answer is 'A youthful basin with rapid erosion.'

Key Points

• Hypsometric Curve:
  • A hypsometric curve represents the distribution of elevations in a drainage basin.
  • It displays the relationship between the horizontal cross-sectional area and elevation, typically with elevation on the vertical axis and the proportion of the area below a given elevation on the horizontal axis.
• Interpreting a Steep Rise Followed by a Flat Concave Portion:
  • This type of hypsometric curve indicates a youthful basin.
  • Youthful Basin Characteristics:
    • The steep initial rise suggests a high relief and rapid elevation drop, common in youthful stages where steep slopes lead to high rates of erosion.
    • This rapid erosion increases the vertical incision by streams.
    • The flat concave portion suggests areas of lower elevation that have not yet been significantly eroded.

Additional Information

• Other Stages of Basin Development Explained:
  • Mature Basin with Moderate Erosion:
    • A mature basin would exhibit a more balanced hypsometric curve with moderate elevations, reflecting an intermediate stage of erosion and landscape development.
  • Irregular Basin with Multiple Denudation Stages:
    • An irregular basin may have a complex hypsometric curve reflecting the presence of various erosional and depositional phases, including irregularities and undulating terrain.
  • Old Basin with Low Elevation Differences:
    • An old basin would show a hypsometric curve that is nearly flat, indicating minimal elevation differences, extensive erosion, and a landscape nearing peneplain (low-relief) conditions.

The correct answer is 1.4

To calculate the Stream Length Ratio (SLR) for stream orders 3 and 4 using Horton’s Law of Stream Length Ratio, we can use the following formula:

\(SLR = (Ln+1) / (Ln)\)

Here, Ln refers to the total stream length of a given stream order n, and Ln+1 refers to the total stream length of the next higher stream order.

Key Points

• Stream Order 3 (L3) has a total stream length of 36 km.
• Stream Order 4 (L4) has a total stream length of 48 km.

Now, we substitute these values into the formula:

SLR = L4 / L3
SLR = 48 km / 36 km
SLR = 1.3333

By calculation, SLR for stream orders 3 and 4 is 1.3333, which rounds to 1.4

Additional Information

• Stream Number:
  • Refers to the total number of streams at each order within a basin. Horton's Law indicates an inverse relationship between stream order and stream number.
  • Graphical representation shows a negative linear trend in plotting stream order vs. log of stream number, suggesting a geometric progression in stream count as order increases. For example, in a sixth-order river basin, the progression may follow a sequence like 1, 3, 9, 27, etc.
• Bifurcation Ratio (BR):
  • Quantifies the branching pattern of streams within a river network. It is defined as the ratio between the number of streams in a certain order (Sn) and the number of streams in the next higher order (Sn+1): BR = (Sn) / (Sn+1).
  • Bifurcation Ratios are calculated for consecutive stream orders within a river basin. A high Bifurcation Ratio indicates a greater degree of branching or bifurcation.
  • The Mean Bifurcation Ratio indicates how stream segments increase from higher to lower order: Mean BR = ΣBR / Number of BR. This ratio is influenced by geological factors such as relief, rock type, and rock dissection. In regions with relatively homogeneous rock types, the Mean Bifurcation Ratio typically falls between 3 and 5.
  • Geological structures controlling drainage patterns can push the Mean Bifurcation Ratio beyond 5. A low Bifurcation Ratio indicates a tendency for water to accumulate, increasing the risk of flooding.

The correct answer is 3.

Key Points

To calculate the number of streams in the 3rd order given the bifurcation ratio (BR) between the 2nd and 3rd stream orders and the number of streams in the 2nd order, we use the definition of the bifurcation ratio.

The bifurcation ratio (BR) is given by:

BR = (Number of streams in the current order) / (Number of streams in the next order)

Given:

• BR = 4
• Number of streams in the 2nd order (S2) = 12

We need to find the number of streams in the 3rd order (S3). Using the formula:

4 = 12 / S3

Solving for S3:

S3 = 12 / 4
S3 = 3

Therefore, the number of streams in the 3rd order is 3.

The correct option is: A - III, B - IV, C - I, D - II.Important Points

Relative Humidity is the amount of water vapour in the air as a percentage of the amount required for saturation at the same temperature.  Important Points

• Hygrometer:
  • Leonardo da Vinci created a crude hygrometer around 1480.
  • Francesco Folli made tremendous progress and built a functional apparatus model during the 1600s.
  • Robert Hooke was also responsible for key advancements in the hygrometer's technology.
  • Johann Heinrich Lambert, a Swiss polymath, created a more complete version in 1755.
  • In 1783, Swiss physicist and geologist Horace Bénédict de Saussure constructed the world's first hygrometer, which used human hair to calculate humidity.
• Psychrometers: 
  • is essentially a hygrometer.
  • It is made up of wet-bulb and dry-bulb thermometers.
  • The difference in the two thermometer readings is used to determine atmospheric humidity.

Hence, both statements I and II are correct in respect to measuring instruments of relative humidity.

The correct answer from the options given is: D, B, A, C
Important PointsGamma Rays (D):

• Gamma rays have the shortest wavelengths and the highest frequencies in the electromagnetic spectrum.
• They are produced by the hottest and most energetic objects in the universe, such as neutron stars and pulsars, supernova explosions, and areas around black holes.
• On Earth, gamma rays are generated in nuclear explosions and in laboratories.

Ultraviolet (B):

• Ultraviolet light has a shorter wavelength than visible light but longer than gamma rays.
• The sun emits ultraviolet light, but most of it is absorbed by the Earth's atmosphere, protecting us from its harmful effects. However, some of it does reach the surface and can cause sunburn.

Infrared (A):

• Infrared radiation has a wavelength longer than visible light but shorter than microwaves. We can feel infrared radiation as heat.
• It's emitted by anything that's warmer than absolute zero (-273.15 Celsius), including the human body and objects around us.

Microwaves (C):

• Microwaves have the longest wavelengths among the four options.
• They're used in various applications like communications (including cell phones and WiFi), radar, and of course, microwave ovens
• . In the electromagnetic spectrum, they sit between radio waves (which have even longer wavelengths) and infrared radiation.

Maps are the representation of various parts of Earth showing the details on a particular scale. Maps can be classified on the basis of scale into four types.

Key Points

•  Cadastral Maps are drawn on a very large scale, varying from 16 inches to a mile, to 32 inches to a mile. Most of the cadastral map has a scale between 1: 500  and 1: 2,500. They show all possible details of an area. These are drawn especially to demarcate the boundaries of fields, buildings to register the ownership.
• Topographical Maps are drawn on a large scale which is smaller than that of Cadastral maps. They show principal topographic forms like relief, drainage, towns, village, forests, etc. The scale varies from 1:25000 to 1:50000. 
• Wall Maps are also known as classroom maps, as they are used for classroom study. Their scale is smaller than that of the topographical maps but larger than the Globe. The scale for wall maps ranges from 1:100000 to 1:500000.
• Globe is drawn on a very small scale giving general information about the physical, climatic, and economic characteristics of different regions. They have a scale of 1:1000000 or smaller. 

Additional Information

•  Maps on the basis of purpose can be classified into different types. These are Political Maps, Historical Maps, Economic Maps, Weather and Climatic Maps, Relief Maps, Geological Maps, etc.

Hence the correct sequence of maps from larger to smaller scale is  Cadastral, Topographic, Wall, and Globe.

The correct option is (A), (B), and (D) only.

Important Points

(A) Raster data model is a simple data structure: True,

• the raster data model stores data as a grid of cells,
• where each cell is assigned a single value that represents an attribute such as elevation, temperature, etc.
• This makes it a simple and easy-to-understand data structure.

(B) All pixels are of the same size and shape: True

• in a raster data model, each cell or pixel has the same size and shape.
• This allows for regular sampling and makes it easier to perform calculations and manipulations on the data.

(C) Smaller file size: False,

• the file size of a raster data model depends on the number of cells and the resolution of the data.
• In some cases, a raster data model can be smaller in file size than a vector data model, but in other cases, the opposite may be true.

(D) Raster data model is compatible with remote sensing imageries: True,

• the raster data model is widely used in remote sensing as it can efficiently store the gridded data obtained from remote sensing imageries, such as satellite and aerial imagery.
• The regular grid structure of raster data makes it well-suited for storing and processing image data.

(E) Difficult overlay operations: False,

• overlay operations can be performed easily in a raster data model as it stores data as a grid of cells with single values.
• Overlay operations involve combining two or more maps or data sets based on their spatial attributes, and this can be easily achieved in a raster data model by performing operations on the values in the cells of the grid.

Additional Information

Spatial data, in the context of geographic information systems (GIS), refers to data that contains information about the location, shape, and characteristics of geographic features and their relationships with one another. It includes both vector and raster data.

1. Vector data: Represent geographic features as points, lines, or polygon shapes and store the spatial location, and attribute information about those features.

2. Raster data: Represent geographic features as a grid of cells and store the values of each cell as attributes, such as elevation or land-use type.

Some common types of spatial data include:

• Points: Represent discrete locations, such as cities or buildings.

• Lines: Represent linear features, such as roads or rivers.

• Polygons: Represent area features, such as land parcels or political boundaries.

• Raster: Represent continuous surfaces, such as elevation, land cover, or satellite imagery.

These data types can be used in GIS to create maps and perform spatial analysis, such as calculating distances and areas, finding patterns and relationships, and making decisions based on geographic information.

A meteorological satellite is a type of satellite that is primarily used to monitor the weather and climate of the Earth. These satellites can be polar orbiting (covering the entire Earth) or geostationary(hovering over the same spot).  They are used to detect the development and movement of storm systems and cloud patterns. 

Key Points

• TIROS-I refers to Television Infrared Observation Satellite.
• It was the world's first weather satellite. 
• It was launched in April 1960. 
• TIROS imaged large swaths of the Earth's surface, allowing forecasters and scientists to see directly for the first time the large-scale features of the earth's weather systems.
• It operated for nearly three months. 
• By the mid-1960s, the civilian TIROS program launched a series of satellites to provide routine, daily weather observations.
• The program is still in operation today and, in conjunction with other weather satellites, has made space-based weather observations a commonplace of contemporary life.

Additional Information

• TRMM which is Tropical Rainfall Measuring Mission was a joint space mission between NASA and Japan Aerospace Exploration Agency(JAXA). It was designed to monitor and study tropical rainfall. It was launched on 27 November 1997 from Tanegashima, Japan.
• MODIS (Moderate Resolution Imaging Spectroradiometer) is a satellite-based sensor used for earth and climate measurements. There are two MODIS sensors, one on board the TERRA satellite and the other on the AQUA satellite.
• NOAA (National Oceanic and Atmospheric Administration) is an American scientific and regulatory agency that forecasts weather monitors oceanic, and atmospheric conditions, and conducts deep-sea exploration.

Hence TIROS-I was the first meteorological satellite.

The data model in GIS:

• In order to visualize natural phenomena, one must first determine how to best represent geographic space.
• Data models are a set of rules and/or constructs used to describe and represent aspects of the real world in a computer.
• Two primary data models are available to complete this task: raster data models and vector data models.

Key Points

Vector data model:

• Vector data/layers in GIS refer to discrete objects represented by points, lines, and polygons.
• Lines are formed by connecting two or more points and polygons are closed set of Lines.
• Layers represent geometries that share a common set of attributes.
• Objects within a layer have a mutual topology.
• Vector sources include digitized maps, features extracted from image surveys, and many more.

• Components are,
  • Point: A point in GIS is represented by one pair of coordinates (x & y). It is considered a dimension-less object. Most of the time a point represents the location of a feature (like cities, wells, villages, etc.).
  • Line: A-line or arc contains at least two pairs of coordinates (say- x1, y1 & x2, y2). In other words, a line should connect a minimum of two points. The start and endpoints of a line are referred to as nodes while points on curves are referred to as vertices. Points at intersections are also called nodes. Roads, railway tracks, streams, etc. are generally represented by a line.
  • Polygon: In simple terms, a polygon is a closed line with an area. It takes a minimum of three pairs of coordinates to represent an area or polygon. The extent of cities, forests, land use, etc. is represented by a polygon.

Important Points

Advantages:

• Data can be represented at its original resolution and form without generalization.
• The graphic output is usually more aesthetically pleasing (traditional cartographic representation)
• Since most data, e.g. hard copy maps, is in vector form no data conversion is required.
• The accurate geographic location of data is maintained.
• Allows for efficient encoding of topology and as a result more efficient operations that require topological information, e.g. proximity, network analysis.

Disadvantages:

• The location of each vertex needs to be stored explicitly.
• For effective analysis, vector data must be converted into a topological structure. This is often processing intensive and usually requires extensive data cleaning. As well, the topology is static, and any updating or editing of the vector data requires re-building of the topology.
• Algorithms for manipulative and analysis functions are complex and may be processing intensive. Often, this inherently limits the functionality for large data sets, e.g. a large number of features.
• Continuous data, such as elevation data, are not effectively represented in vector form. Usually, substantial data generalization or interpolation is required for these data layers.
• Spatial analysis and filtering within polygons is impossible
• It is a compact data structure and has high cartographic output quality.

Therefore, it is clear that option 'B' is correct about the Vector data model.

the correct answer is:Option 2) C and E only

Important PointsSampling: The concept of sampling involves selecting a portion (sample) from a bigger group (the sampling population). There are three methods of sampling in research:

1. Random/Probability Sampling
2. Non-random/Non-probability Sampling
3. ‘Mixed’ Sampling

 Random/Probability Sampling: In this type, each element in the population has an equal and independent chance of selection in the sample.

Non-Random/Non-Probability Sampling Designs: These designs do not operate on the principle of randomization rather these are used when the number of elements in the population is either unknown or cannot be individually identified.

 Simple Random -

• This is a probability sampling technique where each member of the population has an equal chance of being selected.
• It is a valid probability sampling method.

 Stratified -

• This is a probability sampling technique where the population is divided into subgroups (strata) based on certain characteristics, and then samples are randomly selected from each stratum.
• It is a valid probability sampling method.

 Snowball -

• This is a non-probability sampling technique where initial participants are chosen, and then additional participants are recruited through referrals.
• It does not guarantee that each member of the population has a known, non-zero probability of being selected. So,
• it is not a probability sampling method.

 Cluster -

• This is a probability sampling technique where the population is divided into clusters, and then a random sample of clusters is selected, and all members within the selected clusters are included in the sample.
• It is a valid probability sampling method.

 Convenience -

• This is a non-probability sampling technique where the sample is chosen based on what is convenient or readily available.
• It does not guarantee that each member of the population has a known, non-zero probability of being selected.
• So, it is not a probability sampling method.

So, the correct answer is: C and E only C. Snowball and E. Convenience are not probability sampling techniques.

The thematic map refers to as a specifically themed map for a particular geographic area. It tends to be about specific topics. It is used to illustrate the relationship between a theme and physical space. In any thematic map, which of the following methods are used to record the presence of phenomenon; its spatial pattern, distribution, and dispersion Dot method mapping.

Key Points

• In Dot mapping, the distribution of objects is shown by putting the dots of uniform size, where each dot represents a definite number or quantity.
• It shows the phenomenon, its distribution, and dispersion.
• Examples are Maps showing the distribution of mineral resources, crops, cattle, etc.
• When data are shown in distribution maps with dots, it is called the dot method.
• In it, all data are first converted into round figures.
• Then a scale is supposed, e.g., if one dot represents 500 hectares, we will divide every figure by 500 and the dots marked there will be as many as the figure thus obtained

Additional Information

• In Isopleth Mapping, the statistical data is shown by the line of equal values known as Isolines.
• Examples are Isohyets showing places receiving equal amounts of rainfall and Isobars showing the distribution of equal pressure over an area.
• In Choropleth Mapping, Differential shading is used for making vertical, horizontal, and slant lines.
• Sometimes Blocks, Circles, and Triangles are also used.
• Examples are Maps showing Forest types, location factors for industries, etc 
• In Chorochromatic mapping, Different colors are used to show different objects. For example, the Density of population, Amount, Intensity of rainfall, etc.
• In Choro-Schematic mapping, the Distribution of data is shown by a uniform scheme such as using letters, numbers, shapes, etc. For example, Cotton Distribution may be shown by 'C'.

Hence Dot method Mapping is used to record the presence of a phenomenon, its spatial pattern, distribution, and dispersion.

GIS data format:

• GIS data formats can be categorized into two, spatial and attribute data format.
• Spatial data is a geographical representation of features.
• In other words, spatial data is what we actually see in the form of maps (containing real-world features) on a computer screen.
• Spatial data can further be divided into two types- vector and raster data.

Raster data format:

• Raster data is made up of pixels.
• It is an array of grid cells with columns and rows.
• Each and every geographical feature is represented only through pixels in raster data.
• There is nothing like point, line, or polygon. Easy and efficient overlaying process.
• Raster data format is compatible with remotely sensed imagery.
• If it is a point, in raster data it will be a single pixel, a line will be represented as a linear arrangement of pixels and an area or polygon will be represented by contiguous neighboring pixels with similar values.
• In raster data, one pixel contains only one value (unlike vector data where a point, a line, or a polygon may have a number of values or attributes) that’s why only one geographical feature can be represented by a single set of pixels or grid cells.
• Hence a number of raster layers are required if multiple features are to be considered (For example- land use, soil type, forest density, topography, etc.).
• 

Network analysis with point and line is more compatible with the vector data format.