Water budget of a Ramsar site in Ecuador

Abstract

Wetlands have been degrading and disappearing due to several anthropogenic impacts, such as pollution by discharge of domestic and industrial wastewater, agricultural runoff, land conversion, etc. The assessment and forecast of hydrological processes in wetlands, namely inflows and outflows, is essential for developing and implementing plans aimed at managing and protecting wetlands areas. We estimated the water budget of a Ramsar site, La Tembladera wetland, for a two-year period (2018-2019) by using the water balance method. The evapotranspiration was calculated using the Thornthwaite method and the runoff was estimated using the Curve Number method. The proposed water balance model showed that the major inflows to the wetland were the San Agustín and Bellavista canals, and Estero Pinto, about 92.9% (2018) and 90.5% (2019) of the total inflows. The runoff and wastewater flows represented the minor inflows. The runoff was 0.003% in 2018 and 0.004% in 2019, whereas the wastewater volume accounted for 0.05% of all inflows in both years. The actual evapotranspiration was the major outflow in both years, being 67.1% (2018) and 73.6% (2019) of the total outflows. On the other hand, the irrigation canal was the minor outflow, 32.9% in 2018 and 26.4% in 2019. Therefore, La Tembladera wetland hydrology is mostly linked to the canals system and climate conditions, precipitation and actual evapotranspiration. Our findings could be the basis for further research and developing plans in order to rationally manage and protect this wetland of international importance.