Lab 7: IDRISI's Land Change Modeler

Due: At the beginning of your lab during the week of March 19^th (you have two weeks for this lab).

Marks: 40

Background

The objective of this lab is to introduce you to some of the IDRISI tools that allow you to evaluate land cover change over time, using classified images. You will be working with two sets of data--one of an urban environment near Boston experiencing rapid (rural) housing development (CMA), and the other of an area in Bolivia experiencing rapid deforestation (CT). The images in these datasets have been classified for you, so your task is simply to explore the land cover changes over time.

LOAD DATA information: For this lab:

• Using Windows Explorer, go to: G:\courses\data\IDRISI_labs and copy the lab7.zip file to C:\Data, etc. (refer to Lab 5 for the detailed instructions). Within that zip file you will find two additional zip files--one CMA.zip and the other CA.zip.
• Unzip the appropriate file, and set your project and working folders accordingly (as specified below).
• Please do not save these folders to your H: drive without first zipping them. There may not be a need for you to save any of your work to H: if you answer the questions as you go.

Assignment

Part 1: Exploring Land Use Change around Boston, Massachusetts.

For this part of the lab you are to complete one small section of the IDRISI Tutorial: Part 6 Land Change Modeler (LCM).

• Launch IDRISI Selva
• Unzip the CMA file, place that directory under C:\Data, and set the Project and Working Folders to C:\Data\CMA.
• The two pages of the IDRISI tutorial steps you are to complete in Part I of this lab are available here (PDF). You can access the entire tutorial from C:\Program Files (x86)\IDRISI Selva\Documentation\IDRISI Tutorial.pdf

Before you complete each exercise, you should read through the "Specific Instruction and Questions" section below.

• Tutorial Part 6: Land Change Modeler (LCM)
• 6-1 LCM: Projects and Change Analysis

Specific Instructions and Questions

Exercise 6-1 LCM: Projects and Change Analysis

When you display the images (showing a region in central Massachusetts--referred to as CMA), ensure that the legend is also displayed. By clicking and holding the left-mouse button down on the individual legend land cover / land use categories, the specific land cover / land use will be highlighted.

Question 1. Using the CMA datasets, and the information presented in the Change Analysis Gains and Losses graph, construct a table summarizing the changes to the landscape over the time period (i.e., the Net changes--gains and losses--in each land cover). Present the values of the changes in sq km. (You should ignore the water, wetlands, conifer forest and transportation classes when producing your table.) (3)

Question 2. Using the information presented in the two LANDCOVERXXCMA images, create maps showing the changes and trends in the land cover in the CMA. In your answer to this question we are not only looking for a description of the gains and losses, but also for a consideration of what the conversions were and where they're taking place (e.g., do gains in residential areas appear to account for the loss of forested areas?). (10)

• Using Change Maps, create three maps showing the gains and losses for the mixed forest, deciduous forest, and residential > 2 acres classes.
• Using Spatial Trends of Change module, create trend maps (3rd order) showing the transition from mixed forest to residential > 2 acres, and from deciduous forest to residential > 2 acres. (A brief explanation of a spatial trend map is provided here.)
• It may help you understand the overall nature of the land cover / land use change that occurred in the central Massachusetts area between 1985 and 1999 if you explore some of the other class changes as well.
• Create a two page report in Word:
  • One page should contain six images documenting the changes and trends (it is up to you to decide what the sixth image should show). (This tutorial explains how to produce this page.)
  • One page (maximum) summarizing, in words, the changes to this landscape. In your discussion you should make explicit reference to the figures presented on the first page of your report.

Part 2: LCM and data from Bolivia

In this exercise you will use the tools in the land change modeler to evaluate an area in Bolivia on the edge of the Amazon rain forest. The data is from a rapidly changing area in the Bolivian lowlands known as Chiquitania. The data is used with the permission of Conservation International's Centre for Applied Biodiversity Science at the Museo Noel Kempff Mercado in Bolivia.

Chiquitania is about 200 km North North West of Santa Cruz de la Sierra - a Bolivian boom town of petrochemicals and agribusiness in the Amazon basin. This is a region of rolling hills where the Amazonian rainforest is transitioning into deciduous dryland tropical forest. It is a region not well suited to mechanized agriculture, but has economic potential for both cattle and timber production. In addition, there is some subsistence agriculture that occurs throughout the region. Note that the classification scheme provided with the images does not distinguish between settlements and agriculture. These maps were intended for use in an ecosystem monitoring project, and so both land use classes were designated as 'anthropogenic disturbance'. This class also includes secondary (disturbed) forest. The vast majority of disturbed areas are used for pasture--either for dairy (primarily in the southeast) or beef production.

• Unzip the appropriate files and change your Project and Working Folders to CT
• Display the image LANDCOVER86CT, review the legend and classes that have assigned to the data.
• Use GOOGLE EARTH to locate this image area. (Hint - find Santa Cruz de la Sierra in Bolivia, and then use the GOOGLE EARTH measure tool to locate the area 200 km NNE of the city.) (This KMZ file will get you there!)

• Launch the LCM Change Analysis, create a new LCM project (call it CT), select LANDCOVER86CT as the earlier and LANDCOVER94CT as the later image, and select ROADS94CT and ELEVATIONCT as the basis roads layer and elevation layer respectively. Select Landcover94CT as the special palette file.
• Review the changes that occurred between 1986 and 1994.

Question 3: After reviewing the graph of gains and losses:

• a) How many sq km have been lost to anthropogenic disturbance? (1)
• b) What is this as a percentage of the total area of the image? (1)
• c) Note down the four major landcover classes that are being converted to anthropogenic disturbance, and how many sq km of each have been lost. You will be using this information in your answer to Question 5 below. (2)

• Using Change Maps, create a map of the land cover changes. If you carefully review the map you will notice that there are some categories with very few cells present (i.e., very little of some of the land covers were altered). We can generalize the change map (somewhat similar to removing some of the 'dust' as discussed in class) in this way: create another map of land cover changes, but this time check the box "Ignore transitions less than" and enter 500 hectares. View the map.

Question 4. List the legend classes in the two maps you just created. Comparing the two sets of legend entries (from the ungeneralized and the generalized maps) to the values presented in the change analysis graph of gains and losses, are these results expected? What is the total area of the changes that have been omitted in the second, generalized map? (3)

• Now compare the change in land covers from 1994 to 2000 (change the appropriate values in Project Parameters to the earlier and later images, and click on Continue .... to ensure that your changes are recognized.)

Question 5: By reading the graph of gains and losses:

• a) How many sq km have been lost to anthropogenic disturbance? (1)
• b) What is this as a percentage of the total area of the image? (1)
• c) Produce a table showing the changes over the two sets of time periods to the four major landcover classes that are being converted to anthropogenic disturbance, noting how many sq km of each have been lost during each time period. (Include your observations from Question 3c in the table.) (4)

Question 6: Compare the changes that occurred, with respect to the loss of other land cover classes to the anthropogenic disturbance class, from 1986 to 1994, and then from 1994 to 2000. Include in your answer to this question two Change Maps (showing the transition from All to the Anthropogenic disturbance class over the two time periods). What are some of the notable differences between the transitions that occurred between the two sets of year? (4)

Question 7: For the 1994-2000 changes, create maps and trends to help visualize the changes and the factors contributing to those changes. As in Question 2, prepare a two page report, one page of composed of images, and one page of text describing the change to this landscape. (In your answer you should provide a description of the spatial trends in the maps and an explanation for the patterns in anthropogenic disturbance. In particular, you should include a map showing the Spatial Trend of Change from Deciduous Mature Forest to Anthropogenic Disturbance, and from Savanna to Anthropogenic Disturbance [accepting the defaults for this module].) (10)