Lecture 13: Watershed Delineation and Raster Functions

These flashcards cover key concepts from the lecture on watershed delineation, raster functions, and relational databases.

Join and Relate

Bringing spatial and non-spatial datasets together through a common attribute.

Join

Appends attributes from a non-spatial table to a layer attribute table based on a common attribute.

Relate

Defines a relationship between two tables without appending attributes; allows access to related data through layer attributes.

Relational Database

A database that may include relationships such as one-to-one, one-to-many, many-to-one, and many-to-many between records.

One-to-One Relationship

A relationship where one record in a table relates to one record in another table.

One-to-Many Relationship

A relationship where one record in a table relates to multiple records in another table.

Many-to-One Relationship

A relationship where multiple records in a table relate to a single record in another table.

Many-to-Many Relationship

A relationship where many records in a table relate to many records in another table.

Digital Elevation Model (DEM)

Raster representation of elevation data, available globally at various resolutions.

Sink (in DEMs)

An area surrounded by higher elevation values, also referred to as a depression or pit.

Peak (in DEMs)

An area surrounded by cells of lower elevation values.

Flow Direction

A raster that indicates the direction of flow from each cell to its steepest downslope neighbor.

Flow Accumulation

Calculates the accumulated flow to each downslope cell in a raster.

Raster Analysis

A set of functions that operate on raster data, categorized as local, focal, zonal, and global.

Local Functions

Cell-by-cell operations that do not consider neighboring cell values.

Focal Functions

Functions that create an output based on a focal cell and surrounding cells within a defined neighborhood.

Block Functions

Non-overlapping neighborhood operations where a neighborhood is applied over a processing cell.

Global Functions

Functions that consider all cells in a raster for analysis.