GISTDA Satellite Imagery Reveals Green Water in Pa Sak Jolasid Dam
Thailand's space agency has released satellite data showing a significant color change in the Pa Sak Jolasid Dam, attributed to rapid algae and plankton growth following recent flooding.
On October 7, 2026, the Geo-Informatics and Space Technology Development Agency (GISTDA) released satellite imagery highlighting a notable transformation in the water quality of the Pa Sak Jolasid Dam. By comparing Sentinel-2C data from July 19, 2026, with Landsat-8 imagery from October 1, 2026, officials observed that the water surface has turned green.
According to GISTDA, this phenomenon is a direct result of recent flooding. As floodwaters flowed through surrounding agricultural areas, they carried significant amounts of chemical and organic fertilizers into the reservoir. This influx of nutrients has triggered a rapid proliferation of algae and phytoplankton. The satellite images also confirm that the dam’s water volume has increased substantially, reaching levels near its total capacity.
For residents and travelers in the area, this change in water appearance is a visual indicator of nutrient runoff. While the imagery provides a clear view of the environmental impact of the recent floods, the long-term effects on water quality and the specific duration of this algal bloom remain to be confirmed by environmental authorities. Visitors to the region should be aware that the reservoir's appearance has changed significantly due to these natural and agricultural factors.
