GIS For Engineering (MCQ) 3

Question 1

Which coordinate reference system (CRS) is the standard for GPS receivers and global web mapping services?

Accepted Answer

WGS84 (EPSG:4326)

Answer

WGS84 (World Geodetic System 1984, EPSG:4326) is the global datum used by GPS satellites and services like Google Maps and OpenStreetMap.

Question 2

A GIS engineer needs to calculate the true area of a polygon stored in geographic coordinates (degrees). What must be done first?

Accepted Answer

Reproject to a local projected CRS with linear units

Answer

Area cannot be accurately calculated in degrees because degrees represent angles, not distances; reprojection to a projected CRS (e.g., UTM) with meter or feet units is required.

Question 3

Which remote sensing index is calculated as (NIR - Red) / (NIR + Red) and is used to assess vegetation health?

Accepted Answer

NDVI

Answer

NDVI (Normalized Difference Vegetation Index) uses the contrast between near-infrared and red bands to quantify vegetation density and health.

Question 4

In hydrology GIS, what operation fills sinks in a DEM before delineating watersheds?

Accepted Answer

Fill Sinks (Depression Filling)

Answer

Fill Sinks removes artificial depressions in a DEM that would otherwise create isolated drainage cells with no outlet, corrupting flow direction analysis.

Question 5

What does EPSG stand for in the context of spatial reference systems?

Accepted Answer

European Petroleum Survey Group

Answer

EPSG (European Petroleum Survey Group) created and maintained the registry of coordinate reference systems; the registry is now managed by IOGP but the EPSG acronym is still used.

GIS - Geographic Information System Practice Test

GIS - Geographic Information System Practice Test

GIS For Engineering (MCQ) 3