Second meeting with everyone

For the coming weeks, the team is going to be scattered around the globe, so today, while everyone is still in town, we held our second meeting. We started the meeting by looking at some satellite images and aerial photographs of Borneo. I had pre-identified a couple of interesting sites, namely some plantations on flat land, recognisable by the orthogonal patterns of the cultivated parcels, and some on hilly terrains where roads and parcel boundaries follow contour lines. While scoping out the images in a flat area, we identified some forested areas adjacent to a palm oil plantation and it seems that the structure of the new plantation follows the pattern of old logging roads. It might have been a tree plantation, partially logged then converted to a palm oil plantation.

New patterns emerging from the old ones?

We also identified areas where traditional slash and burn is practised. In those areas, the parcels in fallow take on a different shade than the more mature adjacent forest. We can also see small cultivated parcels. In those areas, the presence of roads is worrying. Are those solely used by the locals or are they also used/built by logging companies attracted by an easily reachable loot…

There were some mysterious patterns in the south-eastern part of the island. Comparing the LANDSAT images from 1990 and 2000 really makes them stand out. Obviously, something happened in between those years. Large scale fires is one possibility that was brought up. Failed rice plantations is another.

1990

2000 Here patterns emerge that weren’t there ten years before

Further west of there, other strange patterns stood out. They show up both on the 1990 and 2000 LANDSAT images.

1990

2000 The patterns are still there

A closer inspection of one of these redish spots on a hi-res photo that is even newer than the LANDSAT 2000 images reveals that it is actually almost barren land. In over ten years, those cleared areas never regenerated themselves. Although it would be hasty to jump to conclusion, those areas might be clear examples of what happens when the topsoil is washed away by heavy rains following a clear cut…

Recent close up on a barren patch

After checking out our area of study from above, Stéphane brought out a bunch of spatial data concerning Borneo, and especially the Sarawak region. There was an abundance of data. I don’t know if all of it will be very useful, but some of it might be especially of interest, namely a bunch of land use maps at 1:25000 scales that span from 1988 to 2003.

Rodolphe and Stéphane are both going to be in Asia for a good part of the summer and they’re both going to spend some time in Malaysia. While they’re there, they’ll get to interact with some potential collaborator to our project and they’ll be able to get information and usable data at the source. We made sure to discuss some means to share data while everyone is on their own and to coordinate our schedules for future meetings. The possibility of Stéphane, carrying a GPS while he’s abroad was also brought up. He’ll be the one spending the most time in Malaysia and he’ll be visiting areas directly affected by palm oil production. We think it will be a good way for him and the rest of the team to identify some interesting sites and to put them in a broader spatial context.

To everyone taking off in the coming days, I wish you luck on your travels.

First look at LANDSAT data

Today Jeff and I had a first look at the LANDSAT data provided to us by Stéphane. That data consists of two sets of images, one from 1990 taken by the LANDSAT 4 and 5 satellites and one from 2000 taken by LANDSAT 7. There are some images missing from the 1990 set. I would say, glancing quickly at the mosaic of images, that +/- 5% of the area of the island is missing. There are three bands in the images. We don’t have extensive descriptions of the files we’ve been given, but we’re guessing that the bands are green, red and near infrared. The pixel size is 28.5m * 28.5m. It is coarse, but we can recognize shapes. For instance, we can see roads and barren land is easily identifiable. As far as vegetation is concerned, we can see shapes of different shades of green. Therefore, we should be able to do a classification to map the plantations and the forest. However, it is bound to be challenging as there are factors that will complicate the task at hand. For instance, the land that is to be mapped is hilly and that creates shadows. The area of the island is quite large and the altitude of the terrain varies. The broad range of climatic conditions will translate in different types of vegetation with their own spectral signatures. Furthermore, the different growth stages of various oil palm plantations will mean that different plantations don’t show up the same way on the images.

The classification will require the identification of valid training sites. To figure out which sites may be used, we are going to have to make use of various resources. For instance, we plan on using hi resolution areal photographs publicly available online (through Google Earth, Virtual Earth, World Wind…) where we can easily identify plantations. Today, we looked at was available through Google Earth. Unfortunately, hi resolution aerial photographs where only available for a very small fraction of the island of Borneo, emphasizing the need to find other sources of information to find training sites. One of those might be the concessions for palm oil plantation maps from the WWF.

Since a picture is worth a tousand words... :

Here is forest (on the left) and a palm plantation (on the right), identified with a hi resolution photo from Google Earth:


If we zoom in a little, we can see the distinct pattern of the palm plantations contrasting with the forest:


And this is what the area looks like on the LANDSAT images from 2000 that Stéphane gave us:


As can be seen, the difference between forest and plantation is obvious to the human eye, let's hope our classification software feels the same way...

May 7 2008 - kickoff

Attending: Rodolphe De Koninck, Stéphane Bernard, Alexis Dorais, and Jeff Cardille.

At this meeting, we talked about the big picture of our research together over the next few years, and made a few specific plans for Alexis, who will be starting on the project early this summer.

Our driving question can be phrased like this:  Is there systematic clearance of land that is being replaced by oil palm?  Is oil palm replacing (a) primary forest; (b) secondary forest (c) barren lands; or (d) other crops?  

Our immediate questions focused on the remote sensing work that will be led by Alexis beginning this summer. In particular, we asked ourselves about the potential ability of the Landsat data to show the important types of land uses in Borneo. Among these were Oil Palm, Rubber, Rice, Timber Plantations, Mixed Agriculture 1 (Rubber in Forests), and Mixed Agriculture 2 (Peat and Mangroves). 

Additionally, there are several questions that  we can/should follow up on in the next few weeks:

1. The full repository of Landsat data will be released for free in the near future. (1) When will this be? (2) Is there likely to be useful data, or will we be limited by the spatial resolution? (3) are there smart algorithms for merging a large number of landsat scenes through time for a land use classification? (3) Can an object-oriented classifier be of use here? What program should we use for the classification? (4) should we create a public database of this work?

Jeff noted a few small items to remember for the future:

1. We might look at the concessions for oil palm listed in the WWF document, and contrast that with Google Earth data.

2. Where will we find ground-truthing info?  This may be google earth or some other strategy. 

3. We might find high-resolution data (through Virtual Earth, world Wind, for example). 

4. Should we create a web mapping server of our data?  

To do:

• S: readings to Alexis
  
• A: shop for computer, 
  
• start a web site (maybe through Google for easy collaboration?), 
  
• read introductory material, 
  
• Begin working with Landsat data provided by Stephane. 
  

Our next meeting together is May 21 at 14h00, in Jeff's lab.