GIS & Geospatial Technology Flashcards

Which type of GIS analysis would a landman use to determine how much of a proposed lease block falls within a federally designated wilderness area?

Answer: Overlay analysis

Overlay analysis combines two or more spatial layers to identify areas of intersection, allowing a landman to calculate acreage of a proposed lease that overlaps restricted federal land.

In GIS, what is a 'geodatabase' and why is it preferred over shapefiles for complex oil and gas land management projects?

Answer: A spatial database format that supports domains, subtypes, and topology rules

A geodatabase is a relational database structure for GIS data that supports advanced features like attribute domains, relationship classes, and topology rules, making it superior to shapefiles for managing complex lease datasets.

A landman needs to locate a well described as being in the SW/4 of Section 12, T2N, R3W. What GIS tool would most efficiently identify the correct 40-acre parcel?

Answer: A PLSS-based spatial query against a BLM GCDB layer

A spatial query against a BLM GCDB PLSS layer using township, range, and section attributes allows a landman to precisely locate and select the described quarter-section parcel.

What is the primary purpose of a 'digital elevation model' (DEM) in oil and gas GIS applications?

Answer: To represent terrain elevation for pipeline routing and drainage analysis

DEMs represent terrain surface elevation as a raster grid and are used in pipeline routing, flood zone identification, and slope analysis critical to oil and gas operations planning.

Which of the following best describes 'geoprocessing' in a GIS workflow for a land department?

Answer: Automated spatial analysis operations that manipulate, transform, or analyze geographic data

Geoprocessing refers to GIS operations like clipping, merging, buffering, and overlaying datasets to automate spatial analysis tasks such as identifying open acreage or calculating lease statistics.

A landman discovers that two adjacent lease polygons in a GIS layer have a sliver gap between them due to digitizing error. Which operation best corrects this?

Answer: Running a topology repair or edge-snapping tool

Topology repair or edge-snapping tools close unintended gaps between adjacent polygons by moving shared vertices into coincidence, fixing sliver errors caused by imprecise digitizing.

When a GIS layer uses the NAD83 datum but a well location is collected in WGS84, what must be done before combining these datasets?

Answer: A datum transformation must be applied to align coordinates accurately

Although NAD83 and WGS84 are very similar, a datum transformation is required for precise work because small coordinate differences can cause positional errors in critical lease and well boundary mapping.