Take a trip along the coastlines of Karnataka and Maharashtra, and you are bound to run into stretches of mangroves and wetlands Not only are these areas breathtaking, but they are also vital to the health of our planet. Mangroves and wetlands are ecologically important areas, providing homes for our biodiversity, protecting coastal areas from strong waves, and also helping clean polluted waters, and are labelled as Ecologically Sensitive Areas (ESA).
However, these vital parts of our environment are facing various threats, mostly to accommodate growing cities. Human activities, such as urban expansion, deforestation, afforestation and mining are causing the disappearance of these areas from our urban spaces. To better understand these challenges and develop ways to protect these vital ecosystems, researchers from the Indian Institute of Technology Bombay have mapped the changes in Maharashtra’s mangroves and wetlands over the past decade.
The focus of this research is on using tools like satellite imaging and remote sensing to understand how the landscapes in Mumbai and the Palghar district of coastal Maharashtra, India, have changed over the past decade, from 2010 to 2020. Specifically, they used LISS-IV satellite imagery, which captures detailed pictures of the Earth's surface with a high spatial resolution of 5.8 meters. This resolution is high enough to help scientists clearly see the different types of land, like mangrove forests and wetlands, and understand how they've changed over time.
Next using a machine learning algorithm known as Support Vector Machine (SVM) classifier, they classified the different regions. Think of SVM as a smart robot that's trained to tell the difference between various land types, especially in complex or overlapping areas. For example, it can very effectively separate mangroves from other kinds of plants and wetlands from other big bodies of water. The SVM uses what are known as spectral indices based on the wavelengths of light that each land type reflects. By analyzing these indices, the SVM can map out the different types of land more accurately, even when the areas look almost the same.
In this study, two main indices were mapped: NDVI (Normalized Difference Vegetation Index) which measures the health and density of vegetation, and NDWI (Normalized Difference Water Index) which maps open water and changes in water content, each providing a different perspective of how land features appear on the satellite images. These indices help in highlighting discreet features that might not be visible in raw satellite images.
The study found that the mangrove areas in the coastal Palghar district decreased by about 15% between 2010 and 2020, while in Mumbai, the mangrove regions increased by 16%. However, the wetland areas have decreased significantly in Palghar by 19%, with no big change seen in Mumbai. The increase in mangroves in Mumbai is likely because of the efforts to protect these areas, showing that conservation efforts can make a real difference!
The research offers clear evidence of how human activities, like urbanization and construction, are impacting these sensitive ecosystems. By understanding these changes, policymakers and environmentalists in India can make better decisions about how to protect these invaluable areas. It also shows that technologies like satellite imagery and tools like SVM can be powerful allies in monitoring and safeguarding natural habitats. By harnessing the power of modern technology, we are now better equipped than ever before to monitor and preserve our precious ecosystems against urbanization and other anthropogenic threats.
This research news was partly generated using artificial intelligence and edited by an editor at Research Matters