Search

South America is experiencing rapid change in forest cover, of both native and planted forest. Forest cover loss is primarily attributable to fire, logging, and conversion of native forest to agriculture, pasture, and forest plantations, and types of change vary within and among the many diverse types of forests in South America. Major changes in forest cover and growing policy concerns underscore an urgent need for research on sustainable forest management and water ecosystem services in South America. Differences in land ownership and management objectives create trade-offs between wood production and water ecosystem services from forests. Work is needed to quantify how forest change and management affect ecosystem services, such as wood production versus water provision. Current scientific understanding of forest management effects on water ecosystem services in South America has important limitations, including a scarcity of long-term records and few long-term integrated watershed studies. Industry, government, universities, and local communities should collaborate on integrated applied studies of forests and water. Data archiving and publically available data are required. The creation of national networks and a multi-country South America network to identify and implement common water research protocols, share results, and explore their implications would promote common and well-supported policies. Hydrologists working in South America are well placed to tackle the challenges and opportunities for collaborative research that will maintain the intrinsic values and water ecosystem services provided by South America's forests. Fil: Jones, Julia. State University of Oregon; Estados Unidos Fil: Almeida, Auro. The Commonwealth Scientific and Industrial Research Organization; Australia Fil: Cisneros, Felipe. Universidad de Cuenca; Ecuador Fil: Iroumé, Andres. Universidad Austral de Chile; Chile Fil: Jobbagy Gampel, Esteban Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentina. Universidad Nacional de San Luis; Argentina Fil: Lara, Antonio. Universidad Austral de Chile; Chile Fil: Lima, Walter de Paula. Universidade de Sao Paulo; Brasil Fil: Little, Christian. Center for Climate and Resilience Research ; Chile. Instituto Forestal; Chile Fil: Llerena, Carlos. Universidad Nacional Agraria La Molina; Perú Fil: Silveira, Luis. Universidad de la República; Uruguay Fil: Villegas, Juan Camilo. Universidad de Antioquia; Colombia

International audience

El presente trabajo, tiene por objeto el analisis del marco tecnologico relacionado con la integracion de sistemas informaticos legados, ademas de esto, se revisaran algunas tecnicas para la exposicion de servicios, esto con objetivo de establecer una arquitectura orientada a servicios que puede ser implementada en el Programa para el Manejo del Agua y Suelo (Promas), y que pueda permitir la integracion a la misma de varios sistemas informaticos que han sido creados y que se encuentran todavıa en funcionamiento. Para poder cumplir este objetivo, es necesario el anali- sis de los principales sistemas informaticos para poder extraer las caracteristicas principales y agruparlos de acuerdo a estas, una vez realizada esta agrupacion es necesario tambien el analisis de algunas de las tecnicas que existen actualmente para poder llevar a cabo esta integracion. Una vez identificadas estas tecnicas,es necesario tambien el establecimiento de una metodologia a seguir para la exposicion de futuros servicios, para esto se ha visto necesario la implementacion de una arquitectura piloto que sea capaz de soportar algunos de los servicios que son considerados como vitales en las actividades diarias del Programa. Al final de la implementacion del mencionado piloto, se podra disponer de una arquitectura orientada a servicios que sea capaz de incluir nuevos requerimientos y adaptarse facilmente a los cambios tecnologicos que puedan presentarse. ispartof: Revista Tecnológica ESPOL vol:27 issue:1 pages:14-21 status: published

Un proyecto de riego se ha planeado en la cuenca del Río Macul, Provincia de los Ríos, para el desarrollo de actividades agrícolas, las cuales representan el principal ingreso económico en la Región. Este sistema integral de control de agua comprende tres embalses, ubicados en los Ríos Macul y Maculillo. Las estrategias de riego son investigadas en un manejo integral de la Cuenca Hidrográfica y de los embalses, mediante el modelamiento de estrategias alternativas de operación de embalses con el objetivo de buscar un balance sustentable entre riego y ecología de los ríos. El modelamiento fue realizado por un período de 42 años de datos hidro-meteorológicos históricos, lo cual permitió analizar estrategias de operación en condiciones climáticas extremas. Los resultados indicaron que los volúmenes de riego del Proyecto exceden los volúmenes de agua disponibles para un riego sustentable. Dos líneas de acción son propuestas para enfrentar los déficits y cubrir las demandas de riego a los beneficiarios: una solución es implementar un calendario de riego deficitario, o la segunda solución implica modificaciones en la altura de las presas. Palabras clave: Operación de embalses, modelación de río/embalses, modelación hidrológica de lluvia escorrentía. An irrigation project is planned in the Macul Basin Ecuador for developing the agriculture as the main income in the region. The proposed water system comprises three large reservoirs damming the rivers Macul and Maculillo. The river basin planning and operation was investigated by modelling alternative reservoir operation strategies aiming at a sustainable balance between irrigation and river ecology by integrated reservoir/river management. The model simulates the integrated water system for long term periods of data, covering also several historical extreme events. Results indicate that the planned irrigation volumes are higher than the available water for a sustainable irrigation. Two lines of action are suggested for reaching the target irrigation demands: one is todesign a deficit irrigation schedule, and the second implies modification in the reservoir’s spillway height. Keywords: Reservoir operation, river/reservoir modelling, mathematical modelling, lumped rainfall runoff modeling.

Investigation was made on the climate change signal for hydrometeorological and hydrological variables along the Paute River basin, in the southern Ecuador Andes. An adjusted quantile perturbation approach was used for climate downscaling, and the impact of climate change on runoff was studied for two nested catchments within the basin. The analysis was done making use of long daily series of seven representative rainfall and temperature sites along the study area and considering climate change signals of global and regional climate models for IPCC SRES scenarios A1B, A2 and B1. The determination of runoff was carried out using a lumped conceptual rainfall-runoff model. The study found that the range of changes in temperature is homogeneous for almost the entire region with an average annual increase of approximately +2.0 C. However, the warmest periods of the year show lower changes than the colder periods. For rainfall, downscaled results project increases in the mean annual rainfall depth and the extreme daily rainfall intensities along the basin for all sites and all scenarios. Higher changes in extreme rainfall intensities are for the wetter region. These lead to changes in catchment runoff flows, with increasing high peak flows and decreasing low peak flows. The changes in high peak flows are related to the changes in rainfall extremes, whereas the decreases in the low peak flows are due to the increase in temperature and potential evapotranspiration together with the reduction in the number of wet days.

Un proyecto de riego se ha planeado en la cuenca del Río Macul, Provincia de los Ríos, para el desarrollo de actividades agrícolas, las cuales representan el principal ingreso económico en la Región. Este sistema integral de control de agua comprende tres embalses, ubicados en los Ríos Macul y Maculillo. Las estrategias de riego son investigadas en un manejo integral de la Cuenca Hidrográfica y de los embalses, mediante el modelamiento de estrategias alternativas de operación de embalses con el objetivo de buscar un balance sustentable entre riego y ecología de los ríos. El modelamiento fue realizado por un período de 42 años de datos hidro-meteorológicos históricos, lo cual permitió analizar estrategias de operación en condiciones climáticas extremas. Los resultados indicaron que los volúmenes de riego del Proyecto exceden los volúmenes de agua disponibles para un riego sustentable. Dos líneas de acción son propuestas para enfrentar los déficits y cubrir las demandas de riego a los beneficiarios: una solución es implementar un calendario de riego deficitario, o la segunda solución implica modificaciones en la altura de las presas. An irrigation project is planned in the Macul Basin Ecuador for developing the agriculture as the main income in the region. The proposed water system comprises three large reservoirs damming the rivers Macul and Maculillo. The river basin planning and operation was investigated by modelling alternative reservoir operation strategies aiming at a sustainable balance between irrigation and river ecology by integrated reservoir/river management. The model simulates the integrated water system for long term periods of data, covering also several historical extreme events. Results indicate that the planned irrigation volumes are higher than the available water for a sustainable irrigation. Two lines of action are suggested for reaching the target irrigation demands: one is to design a deficit irrigation schedule, and the second implies modification in the reservoir’s spillway height. Cuenca Volumen 5 (2014)

La cuenca baja del río Cañar es una planicie costera con alto potencial hidro-económico. Sin embargo, esta zona es expuesta a grandes eventos de inundación. El gobierno ecuatoriano ha invertido en un proyecto de gran magnitud para control de inundaciones. Las alternativas de diseño requieren ser probadas en modelos físicos como soporte para los diseños finales. Las variables asociadas al flujo a través de las compuertas de la derivadora Cañar son investigadas en un modelo físico a escala. Los experimentos determinaron la curva de calibración de la compuerta, la ubicación idónea del muñón de la misma y la profundidad del cuenco disipador. Adicionalmente, se encontraron fenómenos de hoyas oscilantes con láminas de flujo de negativo que podrían producir socavación. Como solución, se recomienda modificar la geometría del talud de ingreso del cuenco disipador por una geometría ajustada al perfil de la descarga de chorro. The Cañar River lower basin is a coastal flat area with a high hydro-economic potential, however this zone is vulnerable to flooding. The Ecuadorian Government invests in a flood control project. The project design alternatives need testing in a physical model for supporting the final design. The variables related to the flow through the radial gates of the diversion works are investigated in a physical model. A discharge curve was calibrated for the gate operation. In addition, the best gate location was determined, as well as the optimum still basin depth. Unusual osculation with negative flow directions were found for specific tests. This phenomenon has a scour effect. In order to solve this problem, changes in the geometry of the still basin entrance are recommended by adjusting it to the flow profile. Cuenca Volumen 5 (2014)

no abstract

Flood peak data for focus catchments in Costa Rica, Ecuador, Chile and Argentina are analyzed to test the hypothesis that, as the size of the hydrological event increases, the effect of forest cover on the peak discharge becomes less important. Previous research suggests that this hypothesis may hold for small catchments (less than 1 km2) but the pattern is less clear for large catchments. The principal study results are for small paired catchments (0.6-10 km2) with different forest covers (forest/pasture) in highland Ecuador and a small (0.35 km2) plantation catchment in southern Chile subjected to logging. The former were analyzed by comparing the corresponding peak discharges for given rainfall events, the latter by comparing the relationships between peak discharge and rainfall event size for the pre- and post-logging periods. In all cases there is relative or absolute convergence of the responses as discharge increases, with convergence likely for flood return periods of around 10 years. More limited data for larger catchments which have undergone either deforestation or afforestation (131 km2 in Costa Rica and 94-1545 km2 in Chile) suggest that the percentage change in forest cover must exceed 20-30% to provoke a measurable response in peak discharge; convergence of peak discharge response at high flows (return periods of around 5 years) for the different forest covers may then be observed. For a 12.9-km2 snowmelt-affected catchment in Tierra del Fuego, Argentina, extreme floods require rain-on-snow events but the data are not sufficient to quantify the complex relationship between forest cover, event return period and peak discharge. In general, forest cover is unlikely to reduce, significantly, peak discharges generated by extreme rainfall but may still offer substantial mitigation benefits for moderate (i.e. more frequent) rainfall events. Cuenca volumen 400

The EPIC FORCE project aimed to develop science-based policy recommendations for integrated forest and water resources management, relevant to extreme events for Costa Rica, Ecuador, Chile and Argentina. Data analysis and model application support the hypothesis that, as the size of the flood peak increases, the effect of forest cover becomes less important. Guidelines for integrated water and forest resources management are developed which recognize this effect but emphasize the role that forests play in reducing the flood levels of more moderate events. The research findings are transferred to policy-making for the four focus countries via a set of policy briefs, taking into account the institutional frameworks, achievable policy objectives and key stakeholders., Facultad de Ingeniería

Los altos pastizales de altura de los Andes tropicales, conocido como páramo, son un ecosistema muy frágil y único. A pesar de las crecientes actividades humanas, muchos de sus procesos geomorfológicos e hidrológicos son todavía muy poco conocidos. Por consiguiente, celebramos el papel de Harden [Harden, CP 2006. Los impactos humanos sobre los sistemas fluviales de cabecera en los Andes del norte y centro. Geomorfología 79, 249-263.] Sobre "Los impactos humanos sobre los sistemas fluviales de cabecera en los Andes del norte y centro" como una valiosa contribución a una mejor comprensión de este complejo ecosistema. Sin embargo, en vista de la literatura disponible, nos gustaría complementar la interpretación de los resultados presentados y discutir algunas de las afirmaciones hechas en el papel. The high altitude grasslands of the tropical Andes, known as páramo, are a very fragile and unique ecosystem. Despite increasing human activities, many of its geomorphological and hydrological processes are still very poorly understood. We therefore welcome the paper of Harden [Harden, C.P., 2006. Human impacts on headwater fluvial systems in the northern and central Andes. Geomorphology 79, 249-263.] about "Human impacts on headwater fluvial systems in the northern and central Andes" as a valuable contribution to a better understanding of this complex ecosystem. However, in view of the available literature, we would like to complement the interpretation of the presented results and discuss some of the claims made in the paper. volumen 96; números 1-2