GIS Quiz: 24 Questions on Spatial Data and Analysis

Correct answer: Analyzing relationships among geographically referenced datasets.

The GIS relates datasets by location to answer a spatial question. Positioning instruments can supply coordinates, but combining existing layers is an analytical task. The output still depends on the input data and assumptions; it does not guarantee that an individual building will flood.

Correct answer: Vector polygons with a land-use attribute for each parcel.

Polygons represent enclosed areas, and attributes describe each feature. This structure keeps parcel geometry together with its land-use category. It is a suitable choice for this task, not a claim that parcels can never be represented in raster form.

Correct answer: Its opening-time attribute.

The point geometry records location, while the opening time is descriptive information attached to the feature. Correcting that attribute does not require moving the point. A feature can be spatially well placed while some of its attributes are wrong.

Correct answer: A raster representing a spatially varying quantity.

A raster organizes values in rows and columns of cells. It can hold modeled quantities such as rainfall as well as imagery. The grid structure says how values are stored, not how they were measured or how accurate they are.

Correct answer: B and D, using open status AND capacity of at least 100.

Both conditions must hold. B and D are open and meet the capacity threshold; C meets only the capacity condition. AND requires both tests, whereas OR would also include records that satisfy just one.

Correct answer: A spatial join using containment.

A spatial join matches features by a chosen spatial relationship rather than a shared identifier. Here, containment links each school point to one district polygon. Boundary points and overlapping districts would require additional rules, but the question excludes those cases.

Correct answer: Buffer the pipeline using the specified distance.

A buffer creates an area within a chosen distance of a feature. The analysis must use suitable distance units and a suitable distance method. This geometric screening zone does not by itself model how a leak or other hazard would spread.

Correct answer: Intersect the two polygon layers.

Intersection retains the shared portions of the inputs. With two polygon layers, it can create polygons where suitable soils and available land overlap. Combining every feature into one dataset would not apply the required both-conditions test.

Correct answer: 90 cells.

Add the two coverages, then subtract the shared cells once: 60 + 50 − 20 = 90. Summing 60 and 50 would count the overlap twice. Dissolving overlapping buffer areas removes their internal separation so the combined footprint is counted once.

Correct answer: A network service-area analysis with a 12-minute travel-cost limit.

A network service area follows connected streets and accumulates travel costs, with restrictions included in the model. A circular distance buffer cannot represent permitted turns or differing road speeds. The result is an estimate under the network and time assumptions supplied.

Correct answer: Reproject the layers to the chosen CRS with suitable transformations.

A coordinate reference system tells the software how to interpret coordinates. Reprojecting transforms coordinates between systems; merely assigning a different CRS label changes their interpretation without performing that transformation. Correct definitions and a suitable transformation are necessary before this overlay.

Correct answer: The network’s endpoint connectivity at the junction.

The small gap is an undershoot: lines that should meet do not share a connection. Correcting the geometry and network connectivity can restore the intended route. A visible crossing is not enough to establish a junction, so the field confirmation matters.

Correct answer: Zero is a recorded amount; NoData is missing information.

A numeric zero is a valid value when the dataset defines it that way. NoData indicates the absence of a valid value here. Replacing missing cells with zero would assert a measurement that was not made and could distort later summaries.

Correct answer: The observation dates, category definitions and methods recorded in the metadata.

Metadata describes how, when and why data were created, including information needed to reuse and combine them. A later download does not mean a later observation. Changes in categories or collection methods can also affect the comparison.

Correct answer: Incomplete coverage, despite accurate locations for the listed parks.

Completeness concerns whether the dataset includes the features it is intended to represent. Accurate coordinates for listed parks do not compensate for omitted parks. A count based on this inventory would need to acknowledge its incomplete coverage.

Correct answer: Estimates produced by spatial interpolation.

Interpolation uses known values to estimate values at locations without observations. Filling the display does not create new measurements. The method, sample distribution and underlying geographic variation affect how useful the estimates are.

Correct answer: 6.

Zonal statistics summarizes values within each zone. The arithmetic mean is (2 + 4 + 6 + 12) ÷ 4 = 6. The sum is 24 and the median is 5; neither answers the request for the mean.

Correct answer: Positive spatial autocorrelation.

Positive spatial autocorrelation describes the tendency for similar values to occur near one another. Both high–high and low–low associations contribute to that idea. Whether a measured pattern is statistically unusual requires a suitable test; the description alone does not establish significance or cause.

Correct answer: Rates show overall spatial clustering, without identifying its cause.

The global statistic evaluates an overall pattern of spatial association. A significant positive result supports clustering under the test’s assumptions, but it does not identify a causal process or label every individual district as a local cluster. Explanation requires additional evidence.

Correct answer: The zoning effect of the modifiable areal unit problem (MAUP).

With the number of districts held at 10, changing their boundaries changes which observations are grouped together. Aggregate summaries and relationships can therefore change. This is the zoning component of MAUP; the original household observations need not have changed.

Correct answer: No; the district relationship does not establish residents’ circumstances.

The result describes districts, not the locations or circumstances of particular residents. Assigning the aggregate relationship to individuals risks the ecological fallacy. Area-level data can still be useful when the conclusions remain at the level they support.

Correct answer: Reporting effort and participation may vary spatially, biasing the observed pattern.

Crowdsourced records reflect where people contribute as well as the phenomenon being reported. Unequal participation can bias the apparent pattern, even if each location is accurate. Assess reporting coverage and seek independent evidence before inferring prevalence.

Correct answer: B wins, showing that the ranking depends on the stated priorities.

Initially, A scores 7.5 and B scores 5.75. With access weighted 0.25 and low cost 0.75, A scores 4.5 and B scores 7.25. The ranking reverses, illustrating sensitivity to weights. A suitability score reflects the chosen criteria and priorities, not an objective guarantee of the best site.

Correct answer: Location histories can still expose people, so assess disclosure risk.

Sequences of locations and times can reveal movement patterns and sensitive places such as home locations. Removing names alone does not remove that exposure. Sharing should be limited to what the purpose requires, with appropriate safeguards rather than an unsupported anonymity claim.