Browsing by Autor "Wouter Buytaert"

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Agro-climatic suitability mapping for crop production in the Bolivian Altiplano: A case study for quinoa
(Elsevier BV, 2006) Sam Geerts; Dirk Raes; Ligia García; Carmen Del Castillo; Wouter Buytaert
Establishing glacier proximal meteorological and glacier ablation stations in different climatic zones along the South American Andes.
(2024) Owen King; Tom Matthews; Marcos Andrade; Juan‐Luis García; Claudio Bravo; Wouter Buytaert; Juan Marcos Calle; Alejandro Dussaillant; Tamsin Edwards; Iñigo Irarrázaval
Climate change has had a significant impact on the behaviour of the high mountain cryosphere, with widespread glacier retreat and mass loss now occurring in most of the planet&#8217;s glacierised mountain ranges over multi-decadal timescales. If we are to accurately understand the impacts of deglaciation on freshwater availability to communities downstream, robust modelling of future glacier meltwater yield is paramount. Meteorological observations at glacierised elevations are essential to drive simulations of the energy balance at glacier surfaces, and therefore glacier melt, although such records are sparse in most high mountain regions due to the logistical challenges associated with making even short-term measurements. The scarcity of high-altitude meteorological observations has resulted in only limited understanding of factors such as the spatial and temporal variability of temperature lapse rates, precipitation amounts and phase, and the prevalence of conditions suited to sublimation, all of which have an important influence on glacier mass loss rates at high elevation.Here we summarise the installation of meteorological and glacier ablation stations in different climatic zones of the South American Andes - the Tropical Andes of Peru (Nevado Ausangate basecamp, 4800 m, (13&#176;48'45.96"S, 71&#176;12'53.18"W) and Bolivia (Laguna Glaciar, 5300 m, 15&#176;50'10.59"S, 68&#176;33'11.30"W), the Subtropical Andes (Glaciar Universidad, Chile, 2540 m, 34&#176;43'10.07"S, 70&#176;20'44.98"W) and Patagonian Andes (Lago Tranquillo, Chile, 280 m, 46&#176;35'47.00"S, 72&#176;47'38.91"W) &#8211; as part of the NERC-funded Deplete and Retreat Project. Meteorological station records include time series of air temperature and pressure, relative humidity, wind speed and direction, incoming and outgoing short- and longwave radiation, precipitation amount and phase. Coincident glacier ablation is monitored at each site using &#8216;Smart Stakes&#8217;, recording surface elevation change on-glacier. We describe station situation, installation and preliminary measurements, along with aims and objectives of analyses using the meteorological time series.
Glacial melt content of water use in the tropical Andes
(IOP Publishing, 2017) Wouter Buytaert; Simon Moulds; L. Acosta; Bert De Bièvre; Carlos Francisco García Olmos; Marcos Villacís; Carolina Tovar; Koen Verbist
Accelerated melting of glaciers is expected to have a negative effect on the water resources of mountain regions and their adjacent lowlands, with tropical mountain regions being among the most vulnerable. In order to quantify those impacts, it is necessary to understand the changing dynamics of glacial melting, but also to map how glacial meltwater contributes to current and future water use, which often occurs at considerable distance downstream of the terminus of the glacier. While the dynamics of tropical glacial melt are increasingly well understood and documented, major uncertainty remains on how the contribution of tropical glacial meltwater propagates through the hydrological system, and hence how it contributes to various types of human water use in downstream regions. Therefore, in this paper we present a detailed regional mapping of current water demand in regions downstream of the major tropical glaciers. We combine these maps with a regional water balance model to determine the dominant spatiotemporal patterns of the contribution of glacial meltwater to human water use at an unprecedented scale and resolution. We find that the number of users relying continuously on water resources with a high (>25%) long-term average contribution from glacial melt is low (391 000 domestic users, 398 km 2 of irrigated land, and 11 MW of hydropower production), but this reliance increases sharply during drought conditions (up to 3.92 million domestic users, 2096 km 2 of irrigated land, and 732 MW of hydropower production in the driest month of a drought year). A large proportion of domestic and agricultural users are located in rural regions where climate adaptation capacity tends to be low. Therefore, we suggest that adaptation strategies should focus on increasing the natural and artificial water storage and regulation capacity to bridge dry periods.
High-resolution hydrometeorological data from a network of headwater catchments in the tropical Andes
(Nature Portfolio, 2018) B. F. Ochoa‐Tocachi; Wouter Buytaert; Javier Antiporta; L. Acosta; Juan Diego Bardales; Rolando Célleri; Patricio Crespo; Paola Fuentes; Junior Gil‐Ríos; Mario Guallpa
Impacts of land use on the hydrological response of tropical Andean catchments
(Wiley, 2016) B. F. Ochoa‐Tocachi; Wouter Buytaert; Bert De Bièvre; Rolando Célleri; Patricio Crespo; Marcos Villacís; Carlos Llerena; L. Acosta; Mauricio Villazón; Mario Guallpa
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.
Quantifying and Regionalizing Land Use Impacts on Catchment Response Times With High‐Frequency Observations
(Wiley, 2026) A. Ross; B. F. Ochoa‐Tocachi; Vivien Bonnesoeur; Braulio Lahuatte; Paola Fuentes; Javier Antiporta; Mauricio F Villazon; Wouter Buytaert
Abstract Land use and land cover change (LUCC) can affect the hydrological response time of rivers. However, it is difficult to generate robust and quantitative evidence of this impact at the catchment scale. This lack of evidence also affects the development of rainfall‐runoff models to make ex‐ante predictions. Here, we analyze high‐frequency observational data from a network of pairwise catchments in the tropical Andes and find a statistically significant impact of intensive land use on the hydrological response time, which can be used for regionalization. First, we isolated individual rainfall response events from 5‐min precipitation and discharge time series of 16 catchments (8 pairs). We then fitted unit hydrographs on these events to estimate the catchment response times. These response times were subsequently regionalized by, first, applying a forward stepwise regression to select statistically significant catchment characteristics including land use and land cover, then, fitting a linear mixed‐effects model with the selected characteristics to account for within‐site variability between pairs. We find that catchments with intensive land use have a significantly quicker response than their natural counterparts. Differences were often sub‐hourly, highlighting the value of high‐frequency monitoring. Forward stepwise regression identified only catchment area and intensive land use percentage (LUP) as statistically significant predictors. Model coefficients show that, even when considering other catchment characteristics, increasing intensive LUP decreases response times. This study provides solid evidence and a robust methodology to quantify the impacts of LUCC on catchment hydrology.
Rapid decline of snow and ice in the tropical Andes – Impacts, uncertainties and challenges ahead
(Elsevier BV, 2017) Mathias Vuille; Mark Carey; Christian Huggel; Wouter Buytaert; Antoine Rabatel; Dean Jacobsen; Álvaro Soruco; Marcos Villacís; Christian Yarlequé; O. Elison Timm