Deltas
Using Geographic Information Systems and Remote Sensing
1989
432
742
453
2009
These two columns of maps show the change in vegetation from 1989 to 2009. Throughout the 20 years it is clear that significant changes have occurred. When studying the maps it can be seen that there is a significant change in vegetation towards the North and South of the Mekong River Delta. The changes in colour show that some of the previously waterlogged, flooded or shrimp producing fields have changed or been converted back into more thriving rice crop or mangrove fields. The typical land cover of this area is mangrove but this has changed over time by human activity. Many mangrove fields have been modified into shrimp fields or pods due to the change in demand. This trend is not thought to be stable and there could be another significant change in land use in the future (Lam-Dao, Pham-Bach, Nguyen-Thanh, Pham-Thi and Hoang-Phi 2011).
However, the most significant conclusion to be drawn from the comparison of the two maps is that the various blues on the 2009 image are water fields which have been converted to shrimp fields, it seems that from 1989 over half of the previously suspected mangrove fields have been converted. This has had a major impact upon the forest decline (Lam-Dao, Pham-Bach, Nguyen-Thanh, Pham-Thi and Hoang-Phi 2011). These conclusions could not have been made without the use of GIS and RS.
From previous research which suggested that there has been significant large scale erosion of the Mekong River Delta, it was expected that when the two images from 1989 and 2009 where layered on top of one another and transparency levels were changed, that it would indicate a significant change in the coastline (Kuenzer 2012). However when this was done it didn't seem to show that much of a difference, as illustrated to the right. These images are in the 453 band combination and show the use of the swipe layer tool to allow for closer examination through ArcMap.
Swipe Layer Icon Taken from the Effects Toolbar
