Geographical Techniques Questions and Answers

Answer: B

Change in land use and land cover is detected by overlay analysis.

In overlay analysis two or more map layers of the same area are superimposed and combined. Overlaying a land use map of one date on a map of another date shows, cell by cell or polygon by polygon, where forest became farmland, farmland became built-up area and so on, which is exactly change detection.

Proximity and buffer analysis find what lies within a given distance of a feature, such as all houses within 500 m of a road, and network analysis finds routes and service areas along a network. None of them compares two dates.

Answer: B

The cross profile is the Transverse profile.

A transverse or cross profile is a section drawn across a valley or landform at right angles to its length, for example across a river valley to show whether it is V-shaped or U-shaped.

A longitudinal profile runs along the length of a river from source to mouth. Serial profiles are a set of parallel profiles drawn at regular intervals, and superimposed profiles are several profiles drawn on one base to compare them. Neither is another name for the cross profile.

Answer: B

The best method is Regression analysis.

The question asks how production depends on irrigation coverage. Regression analysis fits an equation relating a dependent variable (production or yield) to an independent variable (irrigated area), measuring how much production changes for each unit change in irrigation and how strong the relationship is.

Index numbers measure relative change over time or space but not the dependence of one variable on another. Factor analysis reduces many correlated variables to a few underlying factors, and cluster analysis groups similar areas together; neither tests the impact of one variable on another.

Answer: D

The parameter is the Form factor.

Horton's form factor is the ratio of basin area to the square of basin length:

\[ R_f = \frac{A}{L_b^{2}} \]

Elongation ratio (Schumm) compares the diameter of a circle of the same area with the basin length, \(R_e = \frac{2}{L_b}\sqrt{A/\pi}\), so the length is not squared. Circularity ratio (Miller) is \(R_c = 4\pi A/P^{2}\), which squares the perimeter, not the length. A slope factor is not a basin-shape parameter of this kind.

Answer: C

It is known as Participatory research.

In participatory research, including participant observation and participatory action research, the researcher takes part in the life and activities of the group being studied, sharing its experience to understand it from inside and often working with its members on the research itself.

Basic research is research aimed at knowledge for its own sake, as opposed to applied research. Primary research means collecting fresh data, as opposed to using secondary sources. 'Elementary research' is not a recognised type. None of these depends on the researcher being part of the group.

Answer: B

The method is Interviews.

The interview method collects data by presenting oral-verbal stimuli (spoken questions) and recording oral-verbal responses, either face to face or by telephone. It allows probing and works with respondents who cannot read or write.

Observation collects data by watching, without asking questions. A questionnaire is a set of written questions that respondents fill in themselves, and a schedule is a printed form that an enumerator fills in; both rest on a written instrument rather than on the oral-verbal exchange that defines the interview.

Answer: C

It is known as a Sample.

A sample is a small part of a population, chosen by a proper method such as random or stratified sampling, so that it represents the whole with a known degree of reliability. Studying a sample saves time and money compared with a complete enumeration.

The population is the whole group being studied, not the small set that represents it. Primary and secondary data describe whether data were collected first-hand or taken from existing sources, not whether they represent a larger group.

Answer: C

The answer is the Normal distribution.

The normal distribution is perfectly symmetrical and bell-shaped, with a single peak at its centre. The peak is the mode, the centre divides the area in half (the median), and the balance point is the mean, so all three coincide.

The Poisson and exponential distributions are positively skewed, with the mean pulled to the right of the mode. A binomial distribution is symmetrical only in the special case p = 0.5 and skewed otherwise, so it does not always have mean = median = mode.

Answer: A

The correct sequence is Energy propagation → Atmospheric interaction → Surface interaction → Recording by detectors → Processing → Application.

In passive remote sensing the energy source is the Sun. Its radiation propagates towards the Earth, passes through the atmosphere where it is scattered and absorbed, then interacts with the surface, which reflects or emits it in characteristic ways. The reflected or emitted energy is recorded by sensors on a satellite or aircraft, the data are processed and interpreted, and finally the results are applied.

Option B starts with surface interaction, and options C and D put surface interaction before atmospheric interaction; options B and C also put application before processing, which is impossible since data must be processed before use.

Answer: B

The answer is Only (b) is true.

(b) is true: remote sensing images are themselves rasters, grids of pixels, so raster data is directly compatible with them.

(a) is false: raster data has a simpler structure than vector data, just a matrix of cells, whereas vector data stores points, lines, polygons and their topology. (c) is false: network analysis (shortest routes, flows along roads or pipes) needs connected lines and nodes, which is a strength of vector data, not of rasters.