Michel Baraer

Climate Change and Tropical Andean Glacier Recession: Evaluating Hydrologic Changes and Livelihood Vulnerability in the Cordillera Blanca, Peru

Climate change is forcing dramatic glacier mass loss in the Cordillera Blanca, Peru, resulting in hydrologic transformations across the Rio Santa watershed and increasing human vulnerability. This article presents results from two years of transdisciplinary collaborative research evaluating the complex relationships between coupled environmental and social change in the region. First, hydrologic results suggest there has been an average increase of 1.6 (± 1.1) percent in the specific discharge of the more glacier-covered catchments (>20 percent glacier area) as a function of changes in stable isotopes of water (δ18O and δ2H) from 2004 to 2006. Second, there is a large (mean 60 percent) component of groundwater in dry season discharge based on results from the hydrochemical basin characterization method. Third, findings from extensive key interviews and seventy-two randomly sampled household interviews within communities located in two case study watersheds demonstrate that a large majority of households perceive that glacier recession is proceeding very rapidly and that climate change–related impacts are affecting human vulnerability across multiple shifting vectors including access to water resources, agro-pastoral production, and weather variability.

New Geographies of Water and Climate Change in Peru: Coupled Natural and Social Transformations in the Santa River Watershed

Projections of future water shortages in the worlds glaciated mountain ranges have grown increasingly dire. Although water modeling research has begun to examine changing environmental parameters, the inclusion of social scenarios has been very limited. Yet human water use and demand are vital for long-term adaptation, risk reduction, and resource allocation. Concerns about future water supplies are particularly pronounced on Perus arid Pacific slope, where upstream glacier recession has been accompanied by rapid and water-intensive economic development. Models predict water shortages decades into the future, but conflicts have already arisen in Perus Santa River watershed due to either real or perceived shortages. Modeled thresholds do not align well with historical realities and therefore suggest that a broader analysis of the combined natural and social drivers of change is needed to more effectively understand the hydrologic transformation taking place across the watershed. This article situates these new geographies of water and climate change in Peru within current global change research discussions to demonstrate how future coupled research models can inform broader scale questions of hydrologic change and water security across watersheds and regions. We provide a coupled historical analysis of glacier recession in the Cordillera Blanca, declining Santa River discharge, and alpine wetland contraction. We also examine various water withdrawal mechanisms, including smallholder agriculture, mining, potable water use, hydroelectric power generation, and coastal irrigation. We argue that both ecological change and societal forces will play vital roles in shaping the future of water resources and water governance in the region.

Migration Amidst Climate Rigidity Traps: Resource Politics and Social-Ecological Possibilism in Honduras and Peru

According to dominant narratives about adaptation to climate change, those facing worst-case scenarios, without means at their disposal to adapt in situ, face an ineluctable set of adaptation strategies that ultimately includes the permanent abandonment of geographic spaces rendered uninhabitable and unproductive for human use. Yet environmental stress and adaptive capacity are distributed unevenly, and power structures play a role in fashioning them. It is argued here that when access to land and water are impacted by environmental stress, the structures that mediate their access are reinforced, even as the adaptive alternatives for smallholders are undermined. In this way, dominant resource regimes set up migration as the primary viable alternative for adaptation among a dwindling set of choices. This framework is applied to two early analogues of climate change impacts: flooded Garífuna villages of Hondurass North Coast and communities enduring glacier recession and shifting hydrologic regimes in Perus Cordillera Blanca. In both cases, stress motivates new forms of migration that reinforce dominant power structures. In Honduras, migrants from wealthier social strata are moving on a more permanent basis, and in Peru, the once historical pattern of labor migration is becoming a practical necessity. These cases underscore the role of political economy in adaptation to climate change and adaptive migration in particular.

Measuring glacier surface temperatures with ground-based thermal infrared imaging

Spatially distributed surface temperature is an important, yet difficult to observe, variable for physical glacier melt models. We utilize ground-based thermal infrared imagery to obtain spatially distributed surface temperature data for alpine glaciers. The infrared images are used to investigate thermal microscale processes at the glacier surface, such as the effect of surface cover type and the temperature gradient at the glacier margins on the glaciers temperature dynamics. Infrared images were collected at Cuchillacocha Glacier, Cordillera Blanca, Peru, on 23–25 June 2014. The infrared images were corrected based on ground truth points and local meteorological data. For the control points, the Pearsons correlation coefficient between infrared and station temperatures was 0.95. The ground-based infrared camera has the potential for greatly improving glacier energy budget studies, and our research shows that it is critical to properly correct the thermal images to produce robust, quantifiable data.

Thermal Imagery of Groundwater Seeps: Possibilities and Limitations

Quantifying groundwater flow at seepage faces is crucial because seepage faces influence the hydroecology and water budgets of watersheds, lakes, rivers and oceans, and because measuring groundwater fluxes directly in aquifers is extremely difficult. Seepage faces provide a direct and measurable groundwater flux but there is no existing method to quantitatively image groundwater processes at this boundary. Our objective is to determine the possibilities and limitations of thermal imagery in quantifying groundwater discharge from discrete seeps. We developed a conceptual model of temperature below discrete seeps, observed 20 seeps spectacularly exposed in three dimensions at an unused limestone quarry and conducted field experiments to examine the role of diurnal changes and rock face heterogeneity on thermal imagery. The conceptual model suggests that convective air-water heat exchange driven by temperature differences is the dominant heat transfer mechanism. Thermal imagery is effective at locating and characterizing the flux of groundwater seeps. Areas of active groundwater flow and ice growth can be identified from thermal images in the winter, and seepage rates can be differentiated in the summer. However, the application of thermal imagery is limited by diverse factors including technical issues of image acquisition, diurnal changes in radiation and temperature, and rock face heterogeneity. Groundwater discharge rates could not be directly quantified from thermal imagery using our observations but our conceptual model and experiments suggest that thermal imagery could quantify groundwater discharge when there are large temperature differences, simple cliff faces, non-freezing conditions, and no solar radiation.

Does hillslope trenching enhance groundwater recharge and baseflow in the Peruvian Andes

Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, QC H3A 0E8, Canada Department of Civil Engineering, University of Victoria, PO Box 1700 STN CSC, Victoria, BC V8W 2Y2, Canada Byrd Polar and Climate Research Centre, The Ohio State University, 108 Scott Hall, 1090 Carmack Rd, Columbus, OH 43210, USA 4 Instituto Geofísico del Perú, Calle Badajoz #169, Mayorazgo IV Etapa, Ate Vitarte, Lima, Peru Départment de génie de la construction, École de technologie supérieure, 1100 rue Notre‐Dame Ouest, Montreal, QC H3C 1K3, Canada Correspondence Lauren D. Somers, Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, QC, Canada, H3A 0E8. Email: Lauren.Somers@mail.mcgill.ca

Trace-metal contamination in the glacierized Rio Santa watershed, Peru

The objective of this research is to characterize the variability of trace metals in the Rio Santa watershed based on synoptic sampling applied at a large scale. To that end, we propose a combination of methods based on the collection of water, suspended sediments, and riverbed sediments at different points of the watershed within a very limited period. Forty points within the Rio Santa watershed were sampled between June 21 and July 8, 2013. Forty water samples, 36 suspended sediments, and 34 riverbed sediments were analyzed for seven trace metals. The results, which were normalized using the USEPA guideline for water and sediments, show that the Rio Santa water exhibits Mn concentrations higher than the guideline at more than 50% of the sampling points. As is the second highest contaminating element in the water, with approximately 10% of the samples containing concentrations above the guideline. Sediments collected in the Rio Santa riverbed were heavily contaminated by at least four of the tested elements at nearly 85% of the sample points, with As presenting the highest normalized concentration, at more than ten times the guideline. As, Cd, Fe, Pb, and Zn present similar concentration trends in the sediment all along the Rio Santa.The findings indicate that care should be taken in using the Rio Santa water and sediments for purposes that could affect the health of humans or the ecosystem. The situation is worse in some tributaries in the southern part of the watershed that host both active and abandoned mines and ore-processing plants.