FCT's hydrological monitoring initiative aims to understand the hydrological response to changes in vegetative cover. Studies in other areas suggest that conversion of native land cover to agricultural use within a given catchment may reduce the land's ability to regulate water flow and may alter annual water yield, as well as increasing sediment load. Year-round availability of water in the Nudo del Azuay is important for the downstream production of hydroelectricity in the Paute-Molino Complex, as well as for local communities and riparian ecosystems.
Suspended sediment production in the headwaters of the Tropical Andes
FCT will measure suspended sediment in the upper Mazar River using an automated stream sampler. The automated sampler will measure stream flow and also take periodic stream samples. It is located in a catchment draining well-conserved high montane evergreen forest, as well as shrubby and grass páramo. This project aims to characterize temporal changes in sediment load in a well-conserved ecosystem.
In May 2013, Beverley Wemple, Ph.D., of the University of Vermont, visited the Nudo del Azuay. She is a forest hydrologist whose research investigates how the management of the mountain landscape alters the processes of runoff generation and sediment production in steep, headwater catchments. She will advise FCT scientists in the design, installation, and analysis of the information generated by the automatic sampler.
This project represents collaboration with a local hydroelectric producer, CELEC EP – Unidad de Negogio HidroAzogues, FCT field technicians, and the University of Vermont. We plan to conduct laboratory analysis of the water samples collected in cooperation with students at the University of Azuay in Cuenca.
Rainfall and run-off in paired catchments
Between 2010 and 2013, FCT and scientists at the University of Cuenca initiated a hydrological monitoring study in four catchments of the Pallcayacu river, varying in size from 13 to 115 hectares. This area is located in the eastern Andean cordillera, a region that exhibits strong seasonality with pronounced wet and dry seasons. Cloud cover is common year-round, and while cloud capture and stem drip are hypothesized to influence local water production, they constitute a poorly understood component of the region's hydrological cycle. Studies in other areas have shown that denuded hillsides have inefficient cloud capture and experience greater runoff following heavy rain.
In each of the four study catchments, we installed a rain collector to measure precipitation and a weir to measure surface water discharge, as well as situating two weather stations in the region. The catchments are paired: comparing well-conserved high montane evergreen forest to degraded forest with a significant proportion of pasture.
This initiative will provide some of the first hydrological data about the Nudo del Azuay and contribute toward a greater understanding of the interaction between land cover, run-off and water production. FCT hopes that the data collected from this study will help improve hydrological models of the Nudo del Azuay. We will also use the results of this initiative to direct conservation activities to areas of high hydrological value.
Data Collection and Analysis
FCT has committed to making data from this initiative available for interested researchers. Complete weather data is available for 2010, as is precipitation data (incomplete for some catchments due to equipment malfunction and installation times). We will begin posting weather, precipitation, and stream flow data for 2011 as it becomes available.
Precipitation - Tamiamanga (August-December)
Available reports and studies related to this project
Buytaert, W., Celleri, R., Willems, P., De Bièvre, B., & Wyseure, G. (2006). Spatial and temporal rainfall variability in mountainous areas: A case study from the south Ecuadorian Andes. Journal of Hydrology, (329), 413-421.
Guallpa, M. & R. Célleri. (2013). Efecto de la estimación de la presión atmosférica sobre el cálculo de niveles de agua y caudales. Aqua-LAC, 5(2), 56-68.
Hampel, H., Cocha, J., & Vimos, D. (2010). Incorporation of aquatic ecology to the hydrological investigation of ecosystems in the high Andes. Grupo de Ciencias de la Tierra y del Ambiente, Universidad de Cuenca.
Hampel, H. (2011). Informe Final: Determinación de los efectos de las variables ambientales sobre las comunidades de organismos acuáticos. Cuenca, Ecuador: Grupo de Ciencias de la Tierra y del Ambiente, Universidad de Cuenca.
Hartsig, J. (2011). The Effects of Land-Use Change on the Hydrological Properties of Andisols in the Ecuadorian Páramo (Master's thesis). The University of Tennessee, Knoxville, Tennessee.
Lozano, J. (2011). Impacto del cambio de coberturas en el rendimiento hídrico y la retención & producción de sedimentos en 5 subcuencas de la cuenca baja del Río Paute: análisis de escenarios utilizando el modelo InVEST. Cali, Colombia: The Nature Conservancy.
Thompson, S. (2011). Análisis histórico de la cobertura del suelo de la subcuenca del bajo río Mazar. Cuenca, Ecuador: Fundación Cordillera Tropical.