Lecture

Altitude Models and Derived Variables

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Description

This lecture introduces geographic information systems and covers discrete variables, spatial properties, autocorrelation, basic elements of digital elevation models, derived products like slope, orientation, curvature, flow lines, watershed boundaries, continuous variables, sampling, contour lines, interpolation, data layer interactions, and thematic variables derived from altitude models. It also explores visibility analysis, shadow casting, solar radiation analysis, drainage lines, watershed limits, flood zones, rockfall hazard mapping, and schistosomiasis transmission risk assessment.

In MOOC

Geographical Information Systems 2

The second part of the course deals with spatial analysis methods and georeferenced information representation techniques. In particular, you will learn how to:

Analyze the spatial properties of discrete variables, for example by quantifying spatial autocorrelation;
Work with continuous variables (sampling, interpolation and construction of isolines)
Use digital elevation models (DEMs) and their derivatives (slope, orientation, etc.);
Use geodata superposition techniques;
Produce cartographic docu

Official source

Quiz

Related concepts (32)

Geographic information system

A geographic information system (GIS) consists of integrated computer hardware and software that store, manage, analyze, edit, output, and visualize geographic data. Much of this often happens within a spatial database, however, this is not essential to meet the definition of a GIS. In a broader sense, one may consider such a system also to include human users and support staff, procedures and workflows, the body of knowledge of relevant concepts and methods, and institutional organizations.

Digital elevation model

A digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, moon, or asteroid. A "global DEM" refers to a discrete global grid. DEMs are used often in geographic information systems (GIS), and are the most common basis for digitally produced relief maps. A digital terrain model (DTM) represents specifically the ground surface while DEM and DSM may represent tree top canopy or building roofs.

Geographic information science

Geographic information science (GIScience, GISc) or geoinformation science is a scientific discipline at the crossroads of computational science, social science, and natural science that studies geographic information, including how it represents phenomena in the real world, how it represents the way humans understand the world, and how it can be captured, organized, and analyzed. It is a sub-field of geography, specifically part of technical geography.

Elevation

The elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § Vertical datum). The term elevation is mainly used when referring to points on the Earth's surface, while altitude or geopotential height is used for points above the surface, such as an aircraft in flight or a spacecraft in orbit, and depth is used for points below the surface.

Geographic data and information

Geographic data and information is defined in the ISO/TC 211 series of standards as data and information having an implicit or explicit association with a location relative to Earth (a geographic location or geographic position). It is also called geospatial data and information, georeferenced data and information, as well as geodata and geoinformation. Approximately 90% of government sourced data has a location component. Location information (known by the many names mentioned here) is stored in a geographic information system (GIS).

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Geospatial Analysis: Derived Variables

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Derived Variables 2: Applications and Analysis MOOC: Geographical Information Systems 2

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Discrete Variables, Geometric Properties MOOC: Geographical Information Systems 2

Covers discrete variables in geographic information systems and their geometric properties, including spatial arrangement and autocorrelation.

Derived variables: thematic applications MOOC: Geographical Information Systems 2

Explores thematic variables derived from digital altitude models for various applications.

Digital Elevation Models: Basic Elements MOOC: Geographical Information Systems 2