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Calculate TSI (Trophic state index)

Source: R/tsi.R
tsi.Rd

Calculate TSI. TSI range: 0 - 100.

Usage

tsi(x, type = c("chla", "TP", "TN", "SD"))

Arguments

x

numeric object

type

type of variable used to calculate TSI. See Details for more information.

Value

a numeric value.

Details

Trophic state classification (Carlson, 1996)

  • <30-40, Oligotrophy

  • 40-50, mesotrophy

  • 50-70, eutrophy

  • 70-100, hypereutrophy

Type of variable used to calculate TSI:

  • SD: Secchi depth, meter

  • chla: chlorophyll, ug/L or mg/m3

  • TP: total Phosphorus, ug/L or mg/m3

  • TN: total Nitrogen, mg/L

Carlson (1977): TSI-SD, TSI-Chla, TSI-TP

USEPA (2000): TSI-TN

References

Carlson, R. E. (1977). A trophic state index for lakes. Limnology and Oceanography, 22(2), 361-369.

Carlson, R. E., & Simpson, J. (1996). A Coordinator's Guide to Volunteer Lake Monitoring Methods. North American Lake Management Society, 73-92.

USEPA. (2000). Nutrient Criteria Technical Guidance Manual: Lakes and Reservoirs, 42-44.

Examples

chla <- c(0.12, 0.34, 0.94, 6.4)

tsi(chla, type = "chla")
#> [1]  9.768544 19.985546 29.962003 48.779910

tsi(chla, type = "TP")
#> [1] -26.438562 -11.413558   3.257702  30.931094