“Bonanza en los Andes” was a two-year Geoscientists Without Borders-funded project focused on the Andean community of Zurite, Perú.
Bonanza was designed around three interconnected themes:
- A community-based irrigation canal development project
- A hydrogeologic investigation of water resources in the understudied Andean puna
- An educational program designed to train students in multidisciplinary research to bridge gaps between science and society
Zurite has a population of 4,000 and is located at 3,400 meters above sea level on the edge of the Anta Plain, approximately 30 kilometers northwest of Cusco. More than 70 percent of Zuriteños devote themselves entirely to agriculture and there is a rich history of agriculture and animal husbandry. Major crops include corn, wheat, quinoa and forage for livestock. Rainfall is strongly seasonal, with only 10 percent of the 855 millimeters of mean annual precipitation falling between May and September. Zurite derives irrigation and municipal water from the 6.14-square kilometer Ramuschaka Watershed, which drains grasslands rising dramatically to 4,500 meters above sea level. The Upper Ramuschaka Watershed (URW) is part of the puna biome, a seasonally dry grassland above the tree line and below the permanent snow line along the spine of the central and southern Andes. Many headwater streams originate in the puna and although these streams provide water to Andean communities large and small and are likely to become more important as glaciers recede, their hydrology is poorly understood.
We collaborated with the community to build 1.3 kilometers of irrigation canals. Principal investigators developed formal agreements with three community groups, including the municipality of Zurite. Our project contributed $20,000 to the $70,000 canal project. We also collaborated with engineers on the hydraulic design. More than 100 families directly benefit from irrigation water now reaching their fields by way of the new canals. Principal investigator Oshun gave community presentations on the objectives of the Bonanza project and presented the municipality with a progress report in 2020. The report presents initial results on water resources in the Ramuschaka and a brief assessment of landslide hazards. The hydrologic results will help guide sustainable water management.
The community issued a statement that read in part, “We are infinitely grateful for your support … that perhaps we will never be able to return to you, but for which you should feel a great sense of satisfaction.”
Our hydrogeologic study has produced several key results, many of which are in preparation for publication. First, we identified and mapped the geology of the URW to reveal Eocene sedimentary units include limestone, sandstone and mudstone. An Oligocene quartz monzodiorite intrusion outcrops in the west. Seasonally saturated peat forming wetlands, known as bofedales, are found in low-gradient basins across the upper watershed. Our hydrologic analyses reveal that 60-70 percent of precipitation leaves the watershed as runoff, and the remaining moisture evaporates off seasonally saturated bofedales, or is transpired by puna grasses. Geophysical data show a deeply fractured and weathered interior of upper hillslopes that thins substantially beneath the interior basins of the bofedales. Precipitation falling on the uplands travels via subsurface pathways and collects in the high porosity peat of the bofedales, which act as a sponge and saturate during the wet season. During the dry season, water drains slowly from bofedales through the underlying low-conductivity clay layer. Currently, we are quantifying water storage within and water yield from bofedales, which cover about 12 percent of the watershed but appear to contribute substantial quantities of water to dry season flow.
Over a two-year period, 29 undergraduate and graduate students from seven different disciplines, including geology, geophysics, engineering and environment and community participated in Bonanza. Students enrolled in a year-long program centered on four weeks of field research in Zurite and the URW. In the spring semesters, we taught a preparatory class that cultivated communication across disciplines, introduced students to independent research, guided students in literature reviews and hypothesis development and explored existing data sets. In-class activities were designed to improve essential skills such as science communication, team building, and the Spanish language. By the end of the course, students were mentally and emotionally prepared to travel to and spend a month living in Perú and empowered to take the lead on specific research tasks.
We conducted four-week field campaigns in 2018 and in 2019. In 2018, nine students from Humboldt State University and one student from Lima joined principal investigators to map geology, conduct seismic refraction surveys and install hydrologic monitoring equipment in the URW, and survey the existing and proposed canals in Zurite. In 2019, principal investigators guided 13 students from U.S. universities and five students from Cusco. Students expanded geologic maps, took discharge measurements throughout the watershed, flew a drone to collect aerial imagery to generate a digital elevation model, installed deep and shallow monitoring wells, conducted electrical resistivity surveys, seismic refraction surveys and nuclear magnetic resonance surveys, collected geospatial data using a real-time kinematic GPS and completed surveys of the existing and proposed canal network while collaborating with local engineers on the hydraulic analyses and canal design. Although students specialized in certain research areas, they also rotated through different tasks to gain experience using different equipment and taking measurements. For each field campaign we stayed with host families in Zurite, and students served as informal ambassadors to the community.
In the fall semesters following our two summer field campaigns, students enrolled in a research course. Principal investigators guided students through data analysis, interpretation, figure development, abstract writing and paper writing. Students produced written reports and gave presentations to the class on topics such as: creating a DEM from drone derived imagery, an analysis of current and projected irrigation needs and a water budget of the URW. One student presented a poster on initial results of the seismic refraction surveys at the Fall American Geophysical Union Conference in Washington, D.C. In December 2019, two students presented interpretations of geophysical data and one student presented the results of hydrologic measurements at the Fall AGU Conference in San Francisco, Calif.
The experience cultivated patience, understanding, motivation to improve our planet and, ultimately, peace.
Students left our program with new perspectives: “This trip made me rethink what approach I want to take to grad school (location, concentration), and made me think more about pursuing a career in water resources,” said one student.
Our project proves international research can be designed and conducted in a way that produces benefits to U.S.-based and local students, principal investigators and the local community.