Cálculo de la carga fluvial de plaguicidas en el río Pisque (Ecuador) entre junio de 2018 y mayo de 2019

The Pisque river basin in Ecuador has a high presence of the floricultural industry, hence the aim of the research is to estimate the losses of pesticides that enter the river water through sources such as surface runoff, contact with the ground, permeate of a previous runoff or by infiltration, and that can be measured in the final channel of the Pisque river before its mouth. In order to know the pesticides used, surveys have been carried out with flower producers. The measurements were made in the Granobles and Guachalá rivers, the two tributaries of the Pisque river; and at two separate points on the same river Pisque, one immediately after the conjunction between the two tributaries and a point before their mouth to the next river. The flow gauges were monthly from June 2018 to May 2019. As a sampling method, SPMD and POCIS passive devices were used during the three dry months, from June to August 2018. To obtain the retention rates of the passive devices, a calibration with the pesticides was carried out in the laboratory through a hydrodynamic channel. Twenty-four main active ingredients were identified from the surveys, mostly compounds with Type III and Type IV toxicities. According to the results of the model, the fluvial load of pesticides in surface waters was 2,982.24 Kg between the months of June 2018 to May 2019, with environmental degradation of various compounds along the stretch of the river. La cuenca del río Pisque en el Ecuador tiene alta presencia de industria florícola, desarrollándose aquí un estudio cuyo objetivo es la estimación de la magnitud de las pérdidas de plaguicidas que ingresan al agua fluvial por fuentes como escorrentía superficial, contacto con el suelo, permeado de una escorrentía previa o por infiltración, y que pueden ser medidas en el cauce final del río Pisque antes de su desembocadura. Para conocer los pesticidas utilizados se han realizado encuestas a los productores florícolas. Las mediciones se realizaron en los ríos Granobles y Guachalá, afluentes del río Pisque, y en dos puntos separados en el mismo río Pisque, uno inmediatamente después de la conjunción entre los dos afluentes y un punto antes de su desembocadura al siguiente río. Los aforos de caudal fueron mensuales desde junio 2018 hasta mayo 2019; cómo método de muestreo se usaron dispositivos pasivos SPMD y POCIS durante los tres meses secos, de junio a agosto de 2018. Para obtener las tasas de retención de los dispositivos pasivos se realizó una calib