Efecto de la industria agropecuaria sobre la histéresis durante eventos de caudal en la relación concentración-caudal de DBO, DQO, nitratos y turbidez en la cuenca de páramo andino del río Quinuas

Abstract

Cajas National Park is the main supplier of high quality water for human and industrial consumption in Cuenca. The changes in land use (agricultural industry) and climate change can alter the essential functions of this ecosystem, mainly hydric regulation. In this research, hysteresis loops of Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Nitrate (NO3-N) and turbidity were studied at five minutes intervals, from January 1, 2015 to December 20, 2016, during discharge events in the Quínuas River. For the study, there were two automatic water quality stations (UV-vis absorbance spectrometer) in the upper part (not disturbed sub-basin Virgen) and in the lower part of the basin (disturbed by agricultural industry sub-basin Chirimachay). According the obtained results, COD was the parameter that showed the most notable change in the hysteresis, rotating mainly clockwise in Virgen sub-basin, while in Chirimachay sub-basin counterclockwise prevailed. These differences could be related with the anthropogenic activities in Chirimachay. Such information could apply as baseline in order to identify some deterioration in páramo ecosystems in the future. In this way the knowledge regard hydrogeochemical processes in the páramos is improved, been a key issue for the management of these ecosystems that have not been well studied.