Vegetation change in Muthurajawela

The Muthurajawela Wetland in Sri Lanka is a vital ecological resource that provides many ecosystem services that are essenstial for the wellbeing of the people, the environment, and the Colombo city itself . However, this fragile ecosystem is under the threat of encroachment by human activities and commercial developments. Recently there were two petitions, filed by Cardinal Malcolm Ranjith and the Environmental Justice Center, requesting the court to order the demarcation of the wetland boundaries.

On Jan 27, 2023, the Court of Appeal gave the government of Sri Lanka three months to complete the demarcation of the Muthurajawela Wetland. This decision is a significant step towards protecting the wetland and preventing further damage to its delicate ecosystem.

As an avid supporter of environmental conservation, I was interested in studying the changes in vegetation cover in Muthurajawela over the years. I used satellite imagery to create a Google Earth Engine app that demonstrates the change in vegetation through the Normalized Difference Vegetation Index (NDVI), which is a commonly used parameter for identifying vegetation in multispectral images.

Through my analysis, I found that there has been a significant change in vegetation cover in the area due to urban sprawl and commercial developments. These changes have led to the loss of critical habitats for several species of animals and plants, resulting in a negative impact on the overall biodiversity of the wetland.

Access the Google Earth Engine App here

Here is a timelapse showing the landcover change in the area. Generated with annual composite Landsat images, visualised using SWIR1, NIR, and Red bands.