# Presentation: 574843

## LAND COVER INVESTIGATION

**Data Collection**

**Mapping**

**Land Cover Sample Site and**
**Biometry Protocols**

**Manual and Computer-aided Mapping and Change Over Time Protocols**

## LAND COVER INVESTIGATION

**Collect MANY Land Cover Sample Sites.**
**Map your GLOBE Study Site using the data and topographic maps, aerial photos, etc. with manual mapping or computer-aided mapping.**
**Carry out an accuracy assessment.**
**Analyze change in two images several years apart.**

## USING GPS IN A LAND COVER SAMPLE SITE

**USING GPS IN A LAND COVER SAMPLE SITE**

- If we take the average of 5 minutes of GPS readings, our position is accurate to about ± 5m.
- It is impossible to determine the exact corner location of a single pixel on the ground.
- By collecting GPS data in the center of the site, we know that within the positional accuracy of the imagery and ground, the center pixel is within the 90m x 90m Land Cover Sample.

**We need to compare each Land Cover Sample Site on the ground to the corresponding area on the image.**

## LANDSAT IMAGE

**LANDSAT IMAGE**

**Using the Land Cover data entry pages, you can request your GLOBE Study Site image once you have reported 250 measurements and submitted the GPS coordinates of your school location. **

## MAPPING

**Manual (Basic)**
**Computer-aided**
- satellite image (digital)
- MultiSpec software
- reference data, maps, aerial photos, etc.

## MAP USES

**studying the habitat of a certain animal or plant**
**looking at the succession of fields to forests**
**studying the rate of growth of a particular village, town or city**
**looking at the amount of undeveloped land**
**deciding how to protect water resources **
**deciding where to plant certain crops during the next growing season. **
**deciding new school boundaries**
**choosing where to connect recreational trails to create one continuous system**
**deciding how to efficiently run public transportation**
**studying another specific question**

## MAPPING

## MAPPING

## MAPPING

## MULTISPEC

**Free software for both Macintosh and PC computers.**
**Allows digital manipulation of LandSat images**
- zoom in/out
- examine different band combinations
- examine spectral properties of pixels/groups of pixels
- perform “blue band correction” of images
**Used to perform unsupervised clustering to create a computer-aided land cover type map**

## COMPUTER-AIDED MAPPING

**COMPUTER-AIDED MAPPING**

## COMPUTER-AIDED MAPPING

**COMPUTER-AIDED MAPPING**

## ACCURACY ASSESSMENT

**ACCURACY ASSESSMENT**

## ACCURACY ASSESSMENT

**After we collect many *****Land Cover Sample Sites***** throughout the GLOBE  Study Site, perform an accuracy assessment on the land cover type map.**

**ACCURACY ASSESSMENT**

## ACCURACY ASSESSMENT

**Using the Land Cover Sample Site data, complete the Accuracy Assessment Work Sheet.**

## ACCURACY ASSESSMENT

**Build an empty difference/error matrix.**

**Label the matrix with the titles and MUC classes.**

## ACCURACY ASSESSMENT

**ACCURACY ASSESSMENT**

**Tally each row of data.**

## ACCURACY ASSESSMENT

## ACCURACY ASSESSMENT

**Calculate:**
- Row Totals
- Column Totals
- Total Data Samples

## ACCURACY ASSESSMENT

***Overall Accuracy***** indicates how well the map identifies all land cover types on the ground.**

## ACCURACY ASSESSMENT

***Producer’s Accuracy***** indicates what percentage of the time a particular land cover type on the ground was identified as that land cover type on the map. It expresses how well the map producer identified a land cover type on the map from the satellite imagery data.**

## ACCURACY ASSESSMENT

***User’s Accuracy***** indicates what percentage of the time a particular land cover type on the map is really that land cover type on the ground. It expresses how well a person using the map will find that land cover type on the ground.**

## ACCURACY ASSESSMENT

## ACCURACY ASSESSMENT

## ACCURACY ASSESSMENT

## CHANGE OVER TIME

**Comparing two images several years apart**
- two images , several years apart (digital)
- these must be **registered** (images overlap exactly) to one another
- if you do not have the capability (software) to do this, contact the Land Cover Team to find out how you can have this done for you
- at least one completed land cover type map with accuracy assessment
- MultiSpec
- reference data, maps, aerial photos, etc.

## CHANGE OVER TIME

**Green may indicate an increase in urban type land covers**
** ****Magenta may indicate a decrease in urban type land covers**

**CHANGE OVER TIME**