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 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.
In mid-2010, FCT initiated a hydrological monitoring study in four catchments of the Pallcayacu and Ningar rivers, varying in size from 29 to 1,452 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 a weather station at a topographical high point between the catchments. The catchments are paired: the first pair compares well-conserved high montane evergreen forest to degraded forest with a significant proportion of pasture, while the second pair compares well-conserved shrubby and grass páramo grass to heavily grazed and frequently burned páramo.
Downstream of the four study catchments, FCT will measure suspended sediment in the upper Mazar River using an automated stream sampler. The automated sampler is located in a catchment draining well-conserved high montane evergreen forest, as well as shrubby and grass páramo. This portion of the project aims to characterize temporal changes in sediment load in a well-conserved ecosystem. We will conduct laboratory analysis of the water samples collected in cooperation with students at the University of Azuay in Cuenca.
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's hydrological monitoring initiative trains local people and community park guards to work alongside our technical team as para-hydrologists. After receiving basic training in hydrology, the para-hydrologists assist in downloading data each month, and checking and maintaining the field equipment.
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.
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.