CWD Geographic Information Systems 2

Question 1

Which GIS data model is most appropriate for representing continuous wetland water table depth across a landscape?

Accepted Answer

Raster grid layer

Answer

Raster grids store continuous spatial data as a matrix of cells, making them ideal for representing gradients like water table depth across a landscape.

Question 2

What does NDVI stand for in the context of remote sensing used for wetland mapping?

Accepted Answer

Normalized Difference Vegetation Index

Answer

NDVI (Normalized Difference Vegetation Index) measures plant greenness using near-infrared and red spectral bands and is widely used to identify vegetated wetland areas.

Question 3

A delineator needs to identify hydric soil boundaries using aerial imagery. Which spectral band combination is most useful for distinguishing wet soils from dry soils?

Accepted Answer

Near-infrared and shortwave infrared (NIR-SWIR)

Answer

NIR and SWIR bands are sensitive to soil moisture content, making them the most effective combination for distinguishing wet hydric soils from dry upland soils.

Question 4

In a GIS topology, which relationship ensures that wetland polygons in a layer do not overlap each other?

Accepted Answer

Must Not Overlap

Answer

The 'Must Not Overlap' topology rule validates that no two polygon features share interior area, ensuring clean, non-redundant wetland boundaries.

Question 5

Which coordinate system is recommended by the U.S. Army Corps of Engineers for mapping wetlands at a local project scale in the contiguous United States?

Accepted Answer

State Plane Coordinate System

Answer

State Plane Coordinate System provides high accuracy for local and regional mapping in feet or meters and is commonly used for project-scale wetland delineations.

(CWD) Certified Wetland Delineator Practice Test

(CWD) Certified Wetland Delineator Practice Test

CWD Geographic Information Systems 2