GIS GIS - Geographic Information System Python Scripting and Automation Questions and Answers 2

Question 1

Which Python package is used to reproject geometries and coordinate reference systems in GIS automation scripts?

Accepted Answer

Pyproj

Answer

Pyproj is a Python interface to PROJ, providing coordinate transformation and CRS definition capabilities for reprojection tasks.

Question 2

In Python GIS automation, what is a 'spatial index' (e.g., using the Rtree library) used for?

Accepted Answer

Speeding up spatial queries by enabling rapid identification of candidate geometries without checking all features

Answer

A spatial index (like an R-tree) organizes geometries by bounding box so that intersection or nearest-neighbor queries scan only a small candidate set instead of every feature.

Question 3

What does the GeoPandas 'dissolve()' function do?

Accepted Answer

Aggregates and merges geometries based on a grouping attribute, combining touching or overlapping polygons

Answer

dissolve() groups rows by a specified column and unions all geometries within each group, similar to a SQL GROUP BY with spatial aggregation.

Question 4

In a Python GIS script using Rasterio, what does 'src.transform' represent?

Accepted Answer

The affine transformation matrix that maps pixel row/column coordinates to geographic coordinates

Answer

The affine transform encodes the origin, pixel size, and rotation, enabling conversion between pixel indices and real-world coordinates.

Question 5

Which GDAL command-line utility (callable from Python via subprocess or gdal bindings) converts a vector file to a raster grid?

Accepted Answer

gdal_rasterize

Answer

gdal_rasterize burns vector feature values into a raster grid at a specified resolution and extent.

GIS - Geographic Information System Practice Test

GIS - Geographic Information System Practice Test

GIS GIS - Geographic Information System Python Scripting and Automation Questions and Answers 2