Environmental Water Quality Information

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Environmental Water Quality Monitoring

Trophic state indices of reservoirs around Taiwan: No testing data; Oligotrophic; Mesotrophic; Eutrophic

Statistics Time： Latest Issue

Percentage of the number of severely-polluted water monitoring stations in watersheds around the country: No testing data; 0 ~ 10%; 11 ~ 20%; 21 ~ 40%; 40% above

Statistics Time： Oct, 2024

Percentage of groundwater areas that exceed the standard around Taiwan

Statistics Time： 2024 Q3

Carlson trophic state index？

The index to assess the degree of eutrophication in reservoirs is called the Carlson Trophic State Index (CTSI). The concentrations of three parameters, including Secchi disc depth (SD), chlorophyll-a (Chl-a) and total phosphorus (TP), are used to calculate and form an index value, which can help determine the level of eutrophication of reservoirs.

Reservoir eutrophication degree over the years

River Pollution Index？

The River Pollution Index (RPI) is a comprehensive index used to assess river water quality. The concentrations of four parameters, including dissolved oxygen (DO), biochemical oxygen demand (BOD₅), suspended solids (SS) and ammonia nitrogen (NH₃-N), are used to calculate the RPI, which determines the level of pollution in river water. The levels of pollution are divided into four categories: non/mildly-polluted, lightly-polluted, moderately-polluted, and severely-polluted.

River RPI over the years

Water Basics

The result of excessively low dissolved oxygen

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Environmental Water Quality Monitoring

Carlson trophic state index？

River Pollution Index？

Water Basics

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