Hydrological monitoring
Hydrological monitoring (quantitative and qualitative) began in 1991 in the C1 catchment, in 2013 in C2 and C3, and in 2018 in C4 (Figure 1). Flow monitoring in the four catchments is carried out using an H-type metal flume, with a maximum measuring capacity of 150 L s-1. Flow rate is obtained from the equation proposed by Bos (1989). Water level height is obtained by Thalimedes water level meter with datalogger. From 2013, with the beginning of the monitoring of the C2 and C3 catchments, OTT Orpheus Mini pressure transducers were installed, same devices installed in C4 after its construction in 2018. Water level height data are obtained in an interval of 15 minutes.
Precipitation monitoring has been carried out at the EECFI meteorological station since 1991, initially by means of a PLG 75 rain gauge (Hidrologia S/A) and, currently, by means of a TR-5251 automatic rain gauge (Texas Electronics), with a record frequency of 30 minutes.
Water quality monitoring in the four catchments is carried out through weekly collections of 1 liter of water at the flume outlet, where the following parameters are analyzed in the laboratory: pH, electrical conductivity, suspended solids, turbidity, apparent color, nitrate, phosphorus, potassium, calcium and magnesium, following standardized procedures (APHA, 2005).