A river health status model based on water quality, macroinvertebrates and land use for niyugan river, Cabuyao City, Laguna, Philippines

Abstract

A health status model was developed for Niyugan River. It consists of two component parameters: response and pressure. The response parameters, water quality and Ephemeroptera-Plecoptera-Trichoptera (EPT) proportion measure the current state of the river. Pressure parameters, land use, infrastructure, and riparian vegetation proportion represent the factors that can worsen the current river condition. Water quality indicator values were determined using on-site measurements and analyzed water. Benthic macroinvertebrates were collected from all the sampling sites. Land use, infrastructure, and riparian vegetation proportions were derived from a map created using Arcmap10. For efficient parameter input and sensitivity analysis, a calculator-like interface was developed using Stella. The score resulted to 37.07, corresponding to a “poor” health. Sensitivity analyses showed that the health score is influenced at a greater extent, by the combination of water quality indicators rather than the number of water quality indicators in the model and by the magnitude of separate indicators within a parameter category. It is suggested that the model is evaluated using data sets from other rivers to further investigate its sensitivity. This model can serve as a basis for developing more dynamic river health models for the Philippines.