Zhenyi Tsai
Geographer and environmental scientistGlacial lake outburst flood screening, Nepal's Koshi Basin
Mapping who lives in the path of a glacial flood
A screening model for glacial lake outburst floods across Nepal's Koshi Basin — narrowing two thousand lakes down to the settlements, and the people, who would be standing downstream.
A glacial lake outburst flood begins where ice, meltwater, and a fragile natural dam meet. Across the Koshi Basin, roughly two thousand lakes sit in that arrangement — and only a handful will ever fail. The problem is not a shortage of lakes to worry about; it is knowing which ones, and who sits below them.
This project builds a lightweight, repeatable way to triage that question. Rather than model every lake in exhaustive detail, it scores all of them on the three variables that most reliably separate the dangerous from the benign, then carries the survivors through validation, proximity exposure, and downstream flood-path analysis — the same path a hazard analyst would walk, made legible on a map.
Establishing the ground
A basin of extremes, from Everest to the plains
Does the model hold up?
Checking a fast model against a careful one
A screening model is only as trustworthy as its agreement with slower, field-based work. Validated against ICIMOD's authoritative inventory of 42 potentially dangerous glacial lakes, the three-factor model recovered 29 of them — including the two Rank-I benchmarks, Imja and Tsho Rolpa. For a method this lightweight, a 69% catch is a strong result, and the disagreements are useful in their own right: they mark exactly where rapid screening and detailed assessment diverge.
Who is exposed
From hazard to people
Risk is only meaningful once people enter the frame. Drawing a 5 km danger zone around the 79 high-risk lakes captures roughly 10,808 residents — a deliberately conservative baseline, since outburst floods travel far beyond five kilometres down-valley. Exposure concentrates in the thin, high-mountain valleys threaded between the glaciers.
The sharpest test
The same hazard, two very different consequences
Proximity is a blunt instrument; a flood follows the valley, not a circle. Tracing the actual flow paths of the two marquee lakes turns the abstraction concrete — and reveals how much the downstream geography matters. Tsho Rolpa's corridor down the Rolwaling Khola threatens 9 settlements and about 1,134 residents. Imja's corridor crosses more villages — 20 — yet only ~224 modelled residents, because the upper Khumbu is sparsely and seasonally peopled.
Two Rank-I lakes, comparable hazards, and an order-of-magnitude gap in human consequence. That contrast is the argument for doing flow-path analysis at all.
A geographer whose work moves between the map and the field, usually somewhere high and cold.
Zhenyi Tsai studies how a warming climate reshapes mountain water — and who bears the consequences downstream. The through-line is a habit of pairing spatial analysis with time actually spent on the ground: surveying glacial lakes on the Tibetan Plateau one season, then turning that fieldwork into the kind of GIS models that let an agency decide where to look first.
That fieldwork has been unusually hands-on. With Tsinghua University's Institute of Climate Change & Sustainable Development, Zhenyi surveyed glacial lakes in Shannan Prefecture, assessing outburst-flood risk and tracing how climate-driven shifts in flow and sediment ripple through the basins that supply much of Asia's water — and working alongside Tibetan communities to fold local ecological knowledge into the analysis.
The following year brought a different kind of problem. As an agroecology coordinator for the Qilian County government in Qinghai, Zhenyi helped five Tibetan families move from nomadic pastoralism to settled agriculture — rebuilding thin highland soil into workable loam, designing drip irrigation for a water-scarce valley, and standing up the region's first biogas digester to turn organic waste into household fuel. Between the two sits a consistent interest in the practical, unglamorous work of adaptation.
Back in Vancouver, that shows up as teaching and organizing: building climate-justice curriculum as a UBC teaching assistant, translating climate-wellbeing research into classroom tools, and — separately — certifying the next set of first responders as a Red Cross first-aid instructor. Two degrees underpin it, a BA in Geography & Environmental Science from UBC and earlier study in Political Science & Environmental Studies at the University of Toronto.
Head coach of UBC Muay Thai and past president of the UBC Buddhist Student Association — the discipline-and-stillness end of an otherwise field-heavy life.
Certified Emergency Medical Responder and Wilderness First Responder — useful credentials when your study sites are days from a road.
Works in English and Mandarin, which is what made the Qinghai and Tibet fieldwork possible in the first place.
Résumé
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University of British Columbia
2022 – 2026BA, Geography & Environmental Science (Double Major) · Vancouver, B.C.
- Grade 3.7. Climate Emergency Advisory Board; Student Sustainability Council.
University of Toronto
2020 – 2022Political Science & Environmental Studies · Toronto, Ontario
- 3.9 GPA · Dean's List; G20 Research Group.
Research experience
Agroecology & Permaculture Coordinator
Mar – Nov 2025Qilian County Government, Agricultural Department · Qinghai, China
- Coordinated a permaculture initiative supporting five Tibetan families through the transition from nomadic pastoralism to settled agriculture, across five plots and three growing cycles.
- Designed regenerative soil systems — composting, agroforestry, intercropping — converting marginal highland soil into fertile, yield-ready loam.
- Implemented precision and drip irrigation in a water-scarce valley, and partitioned yak-grazing sectors to integrate livestock and cropland.
- Partnered with local government to secure irrigation infrastructure and establish the region's first biogas digester for renewable household fuel.
Field Research Assistant
Apr – Sep 2024Tsinghua University, Inst. of Climate Change & Sustainable Development · Shannan Prefecture, T.A.R.
- Surveyed glacial lakes on the Tibetan Plateau, assessing outburst-flood risk and documenting potential impacts on ecosystems and communities.
- Analyzed climate-driven shifts in flow and sediment transport across major Tibetan-Plateau river systems and their downstream effects.
- Worked with Tibetan communities to integrate traditional ecological knowledge into risk-management and adaptation strategies.
Teaching & assorted
First Aid Instructor
May 2024 – PresentCanadian Red Cross / Pacific First Aid · Vancouver, B.C.
- Instruct and assess Standard & Emergency First Aid, CPR/AED (A, C, HCP), and Wilderness First Response against national certification standards.
Climate Wellbeing Coordinator
Sep 2025 – May 2026UBC Sustainability Hub · Vancouver, B.C.
- Co-developed a curriculum toolkit translating climate-wellbeing research into classroom-ready strategies for instructors across disciplines.
Teaching Assistant, Geography
May 2023 – May 2024UBC Geography Department · Vancouver, B.C.
- Built and delivered units on carbon accounting, life-cycle analysis, and climate-risk management; developed tutorial curriculum for GEOG 302: Climate Justice.
Organizations
Sustainability Consultant
2022 – 2025Climate Justice UBC · Vancouver, B.C.
- Built an integrated Microsoft Access + ArcGIS database tracking sustainability initiatives, and led community climate-literacy workshops.
Student Sustainability Council
2022 – 2025University of British Columbia · Vancouver, B.C.
- Organized a cross-campus climate-action coalition and advanced sustainability into university operations and policy.
Skills
Let's find the water together
Open to research, GIS, and climate-risk work — and always up for a conversation about mountains, mapping, or fieldwork somewhere far from a road.