In cartography: mapping act of making a map

In mathematics: mapping the process of creating a picture or diagram that represents something

To make a map, it require the following;

• Collect data using devices e.g. remote sensors, GPS, drones, cellphones etc.
• Use of symbols
• Measure distances
• Create filters to screen data in a variety of ways
• Define a bounding region with buffers
• Classify raster data
• Understand topology, geocoding and modeling

• Thematic maps - convenient map of differently colored patches, each representing a particular theme
• Heat maps - provides a rough picture of quantity distribution
• Cluster maps - too many points are fused into a single cluster point for convenience
• Bubble maps - provides a quick general understanding of the relationship between quantities and locations at a glance
• Quantity maps - show the variety in quantities of something depicted on the map
• Interactive maps - online maps

Objective - sustain steady food production

Method- band combination

Scientific foundations

• normalized difference vegetation index (NDVI) values range from +1.0 to -1.0
• Areas of barren rock, sand, or snow usually show very low NDVI values 0.1 or less
• Sparse vegetation such as shrubs and grasslands or unhealthy crops may result in moderate NDVI values ~ 0.2 to 0.5
• High NDVI values ~ 0.6 to 0.9 means dense healthy vegetation at their peak growth stage

Principle- Wavelengths of visible and near-infrared sunlight are reflected by the plants

Technique- uses heat maps to display the vegetation density

Analysis- Visualization of the state of crops based on the vegetation indices e.g. NDVI, modified soil-adjusted vegetation index (MSAVI), Enhanced Vegetation Index (EVI), and Red-Edge Chlorophyll Vegetation Index (RECl)

Generic question- do we have enough food for the growing population?

Management & policy- GIS is a vital tool for crop monitoring for food security

Look for an article that map species habitat. Submit a summary based on the following issues

• Objective
• Method
• Scientific foundations
• Principle
• Technique
• Analysis
• Generic question
• Management & policy

Queries about this Session, please send them to: jmwaura@jkuat.ac.ke

*References*

• Geographic Information System Basics, 2012 J.E.Campbell & M. Shin
• Fundamentals of GIS, 2017 Girmay Kindaya
• GIS Applications for Water, Wastewater, and Stormwater Systems, 2005 U.M. Shamsi
• Analytical and Computer Cartography, 2nd ed. Keith C. Claike
• Geographic Information Systems: The Microcomputer and Modern Cartography, 1st ed. Fraser Taylor