Question 1

TIN is more efficient than DEM at representing a surface

Accepted Answer

TIN (Triangulated Irregular Network) is more efficient than DEM (Digital Elevation Model) at representing a surface as it uses a series of irregular triangles to model a terrain surface, whereas DEM uses a regular grid of elevation values. TIN can capture more detailed terrain features and reduce data redundancy, making it a more efficient representation of the surface.

Question 2

If a plateau is eroded by gullies, the remaining plateau would be a flat (planar) area bounded by an irregular, many-sided polygon. In the TIN model
A) it would be represented by the irregular, many-sided polygon
B) it would be represented by a number of triangles, each at a different elevation
C) it would be represented by a number of triangles, each at the same elevation
D) it cannot be represented

Accepted Answer

In the TIN (Triangulated Irregular Network) model, a flat area is represented by triangles at the same elevation, as the model uses triangles to approximate the surface.

Question 3

Which of the following is not well represented using TIN?
A) glaciated landscapes
B) fluvially eroded landscapes
C) mountainous landscapes

Accepted Answer

TIN (Triangular Irregular Network) is a terrain representation model that has the capability to represent complex terrains with high accuracy. It is particularly useful for representing fluvially eroded and mountainous landscapes. However, TIN may not be the best choice for representing glaciated landscapes, which typically have a more layered and uniform topography. Other terrain representation models, such as Grid or Point models, may be more suitable for these types of landscapes.

Question 4

Below is a DEM. Which landform is at Locations labelled as 1? g 
A) hill tops
B) ridges
C) valleys
D) steep slopes

Accepted Answer

The answer of Below is a DEM. Which landform is...

Question 5

In the following flow accumulation map derived from the above DEM, ridge lines can be formed by linking locations with a flow accumulation value of  
A) 1129
B) 1000
C) 100
D) 0

Accepted Answer

The answer of In the following flow accumulation map derived...

Question 6

A hydrologically correct DEM is
A) a hydrological model
B) a DEM corrected using a hydrological model
C) a DEM void of depression or sinks
D) a DEM resulted from hydrological analysis

Accepted Answer

A hydrologically correct DEM is one that has been processed to remove depressions or sinks, ensuring accurate water flow modeling.

Question 7

Sinks in a DEM are not caused by
A) sampling effects
B) rounding of elevations to integer numbers
C) spatial variations in the DEM
D) natural depressions on terrain surface

Accepted Answer

Sinks in a DEM are typically caused by sampling effects, rounding of elevations, or natural depressions, not by spatial variations in the DEM itself.

Question 8

As the spatial resolution of a DEM decreases, the number of sinks
A) increases
B) decreases
C) have no change

Accepted Answer

As the spatial resolution of a DEM decreases, the number of sinks increases. This is because with lower spatial resolution, smaller terrain features and depressions may not be properly represented, leading to the filling of these features and the formation of artificial sinks.

Question 9

Slope is measured either in degrees or percentage. 45 degree is equivalent to
A) 1%
B) 45%
C) 100%
D) none of the above

Accepted Answer

A slope of 45 degrees is equivalent to a 100% grade, meaning the rise is equal to the run.

Question 10

The flow direction tool in GIS calculates
A) the direction water will flow along a stream channel
B) the direction water will flow into a catchment
C) the direction water will flow out from a catchment
D) the direction water will flow out from each cell

Accepted Answer

The flow direction tool in GIS calculates the direction water will flow out from each cell in a raster grid, based on the slope or gradient of the terrain. This is essential for hydrological modeling and watershed analysis.

Question 11

Flow accumulation is calculated based on
A) amount of rain flowing through each cell
B) amount of water accumulated from upstream areas
C) flow direction
D) flow length

Accepted Answer

The answer of Flow accumulation is calculated based on
A) amount...

Question 12

On a flow accumulation raster layer, locations having an accumulation value of 0 correspond to
A) stream channels
B) ridge lines
C) pour points
D) none of the above

Accepted Answer

Locations with an accumulation value of 0 correspond to ridge lines as no flow is accumulating in these areas. Stream channels would have a high accumulation value, and pour points would have a value greater than 0 as they receive flow from upstream areas.

Question 13

The flow length tool in GIS with UPSTREAM option calculates
A) downslope distance along a flow path from each cell to a sink or outlet on the edge of the catchment
B) longest distance along a flow path from each cell to the top of the divide of the catchment
C) length of each stream channel within the catchment
D) shortest distance from the highest point to the outlet of the catchment

Accepted Answer

The UPSTREAM option calculates the longest distance along a flow path from each cell to the top of the divide of the catchment, which is described as flow length.

Question 14

The topographic wetness index is a function of
A) elevation
B) slope
C) aspect
D) catchment size

Accepted Answer

The answer of The topographic wetness index is a function...

Question 15

In order to answer the question 'can a tower in the terrain be seen from a given viewpoint?', which of the following GIS operations is the best?
A) viewshed analysis
B) line-of-sight analysis
C) slope measurement
D) aspect measurement

Accepted Answer

The answer of In order to answer the question 'can...

Question 16

To answer the question 'how can an aesthetically unpleasant building be optimally hidden in the terrain in order to preserve the beauty of a landscape?', it is better to use
A) viewshed analysis
B) line-of-sight analysis
C) overlay
D) buffer

Accepted Answer

Viewshed analysis can determine the visibility of the building from different points in the landscape, allowing for the identification of optimal locations for it to be hidden from view. This approach takes into consideration the topography and vegetation of the land, allowing for the preservation of the natural beauty of the landscape.

Quiz 7: Terrain Analysis

TIN is more efficient than DEM at representing a surface

If a plateau is eroded by gullies, the remaining plateau would be a flat (planar) area bounded by an irregular, many-sided polygon. In the TIN model

Which of the following is not well represented using TIN?

Below is a DEM. Which landform is at Locations labelled as 1? g

In the following flow accumulation map derived from the above DEM, ridge lines can be formed by linking locations with a flow accumulation value of

A hydrologically correct DEM is

Sinks in a DEM are not caused by

As the spatial resolution of a DEM decreases, the number of sinks

Slope is measured either in degrees or percentage. 45 degree is equivalent to

The flow direction tool in GIS calculates

Flow accumulation is calculated based on

On a flow accumulation raster layer, locations having an accumulation value of 0 correspond to

The flow length tool in GIS with UPSTREAM option calculates

The topographic wetness index is a function of

In order to answer the question 'can a tower in the terrain be seen from a given viewpoint?', which of the following GIS operations is the best?

To answer the question 'how can an aesthetically unpleasant building be optimally hidden in the terrain in order to preserve the beauty of a landscape?', it is better to use