Impacts of land use on the hydrological response of tropical Andean catchments |
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| Authors: | Boris F Ochoa‐Tocachi Wouter Buytaert Bert De Bièvre Rolando Célleri Patricio Crespo Marcos Villacís Carlos A Llerena Luis Acosta Mauricio Villazón Mario Guallpa Junior Gil‐Ríos Paola Fuentes Dimas Olaya Paúl Viñas Gerver Rojas Sandro Arias |
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| Affiliation: | 1. Department of Civil and Environmental Engineering and Grantham Institute – Climate Change and the Environment, Imperial College London, South Kensington Campus, London, UK;2. Consorcio para el Desarrollo Sostenible de la Ecorregión Andina (CONDESAN), área de Cuencas Andinas, Lima, Peru;3. Regional Initiative for Hydrological Monitoring of Andean Ecosystems (iMHEA), Lima, Peru;4. Universidad de Cuenca, Departamento de Recursos Hídricos y Ciencias Ambientales & Facultad de Ciencias Agropecuarias, Cuenca, Ecuador;5. Escuela Politécnica Nacional, Departamento de Ingeniería Civil y Ambiental, Quito, Ecuador;6. Facultad de Ciencias Forestales, Universidad Nacional Agraria La Molina, Lima;7. Laboratorio de Hidráulica (LHUMSS) & Facultad de Ciencias y Tecnología, Universidad Mayor de San Simón, Cochabamba, Bolivia;8. Empresa Pública Municipal de Telecomunicaciones, Agua Potable, Alcantarillado y Saneamiento de Cuenca (ETAPA EP), Subgerencia de Gestión Ambiental, Cuenca, Ecuador;9. FONAG Fondo para la Protección del Agua, Quito, Ecuador;10. Naturaleza y Cultura Internacional (NCI), Piura, Peru;11. Asociación Peruana para la Conservación de la Naturaleza (APECO), Chachapoyas, Peru;12. Servicio Nacional de Meteorología e Hidrología del Perú, Cusco, Peru |
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| Abstract: | Changes in land use and land cover are major drivers of hydrological alteration in the tropical Andes. However, quantifying their impacts is fraught with difficulties because of the extreme diversity in meteorological boundary conditions, which contrasts strongly with the lack of knowledge about local hydrological processes. Although local studies have reduced data scarcity in certain regions, the complexity of the tropical Andes poses a big challenge to regional hydrological prediction. This study analyses data generated from a participatory monitoring network of 25 headwater catchments covering three of the major Andean biomes (páramo, jalca and puna) and links their hydrological responses to main types of human interventions (cultivation, afforestation and grazing). A paired catchment setup was implemented to evaluate the impacts of change using a ‘trading space‐for‐time’ approach. Catchments were selected based on regional representativeness and contrasting land use types. Precipitation and discharge have been monitored and analysed at high temporal resolution for a time period between 1 and 5 years. The observed catchment responses clearly reflect the extraordinarily wide spectrum of hydrological processes of the tropical Andes. They range from perennially humid páramos in Ecuador and northern Peru with extremely large specific discharge and baseflows, to highly seasonal, flashy catchments in the drier punas of southern Peru and Bolivia. The impacts of land use are similarly diverse and their magnitudes are a function of catchment properties, original and replacement vegetation and management type. Cultivation and afforestation consistently affect the entire range of discharges, particularly low flows. The impacts of grazing are more variable but have the largest effect on the catchment hydrological regulation. Overall, anthropogenic interventions result in increased streamflow variability and significant reductions in catchment regulation capacity and water yield, irrespective of the hydrological properties of the original biome. Copyright © 2016 The Authors. Hydrological Processes. Published by John Wiley & Sons Ltd. |
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| Keywords: | hydrological response land use LUCC Andes pá ramo puna jalca indices |
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