Interaction of light with water under clear and algal bloom conditions

(1) Laramie High School, (2) Wyoming Geographic Information Science Center, University of Wyoming
Cover photo for Interaction of light with water under clear and algal bloom conditions
Image credit: Liz Harrell

Algal blooms are a major problem in water bodies throughout the world. Algal blooms that produce harmful toxins are termed harmful algal blooms (HABs). It is important to monitor water bodies for algal blooms as they can be harmful to humans and animals. Monitoring can also allow management agencies to mitigate the blooms. There are challenges in monitoring water bodies such as time, cost, and remoteness. This study aimed to detect algal blooms with satellite images to enable earlier detection in the future. This can help with earlier warning and advisories that will mitigate negative health effects to humans and animals. Areas with algal blooms behaved like vegetation in certain regions of the electromagnetic spectrum (EMS), while in others it resembled water. As algal blooms became brighter, near-infrared values increased. We also observed a high ratio vegetation index and low mid-infrared values confirm the presence of algae and distinguish them from vegetation. Satellite images can be used to detect algal blooms in water bodies in Wyoming, based on how algae interact with light in the near and mid-infrared regions.

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