Research articles

Articles can be downloaded from the journal links, Google Scholar, or provided free of charge through email request.


UAV-Derived Himalayan Topography: Hazard Assessments and Comparison with Global DEM Products

Watson, C.S. Kargel, J.S. and Tiruwa, B. 2019.

  • We compare the topography of UAV-derived DEMs, three open-access global DEM products, and the 8 m High Mountain Asia (HMA) DEMs (released in December 2017) and assess their suitability for landslide- and flood-related hazard assessments.
  • We outline a workflow for using UAVs in hazard assessments and disaster situations to generate fine-resolution topography and facilitate real-time decision-making capabilities, such as assessing landslide-dammed lakes, mass movement volumes, and flood risk.

Shrinkage of Nepal’s Second Largest Lake (Phewa Tal) Due to Watershed Degradation and Increased Sediment Influx

Watson, C.S. Kargel, J.S. Regmi, D. Rupper, S. Maurer, J.M. and Karki, A. 2019.

  • Phewa Lake is an environmental and socio-economic asset to Nepal and the city of Pokhara. However, the lake area has decreased in recent decades due to sediment influx.
  • The rate of this decline and the areal evolution of Phewa Lake due to artificial damming and sedimentation is disputed in the literature due to the lack of a historical time series.
  • In this paper, we present an analysis of the lake’s evolution from 1926 to 2018 and model the 50-year trajectory of shrinkage

Glacial and geomorphic effects of a supraglacial lake drainage and outburst event, Everest region, Nepal Himalaya

Miles, E.S. Watson, C.S. Brun, F. Berthier, E. Esteves, M. Quincey, D.J. Miles, K.E. Hubbard, B. and Wagnon, P. 2018.

  • A set of supraglacial ponds filled rapidly between April and July 2017 on Changri Shar Glacier in the Everest region of Nepal, before sudden and complete drainage through Changri Shar and Khumbu glaciers (15–17 July).
  • We use PlanetScope and Pléiades satellite orthoimagery to document the system's evolution over its very short filling period and to assess the glacial and proglacial effects of the outburst flood.
  • We also use high-resolution stereo digital elevation models (DEMs) to complete a detailed analysis of the event's glacial and geomorphic effects, which included deep incision and landsliding along the Changri Nup proglacial stream, the collapse of shallow englacial conduits near the Khumbu terminus and extensive, and enhanced bank erosion at least as far as 11 km downstream below Khumbu Glacier.

Optimising NDWI supraglacial pond classification on Himalayan debris-covered glaciers

Watson, C.S. King, O. Miles, E.S. and Quincey, D.J. 2018.

  • Pond classification using Sentinel-2 imagery had the best contrast between water and debris cover.
  • Pond classification using Landsat 8 imagery had large omissions and commissions due to the imagery resolution..
  • ≤10 m resolution imagery was well suited for supraglacial pond classification.

Evolution and Controls of Large Glacial Lakes in the Nepal Himalaya

Haritashya, U. Kargel, J. Shugar, D. Leonard, G. Strattman, K. Watson, C.S Shean, D. Harrison, S. Mandli, K. and Regmi, D. 2018.

  • This study assesses the evolution of three of the most hazardous moraine-dammed proglacial lakes in the Nepal Himalaya—Imja, Lower Barun, and Thulagi.
  • Bathymetry surveys revealed the depth and volume of each lake.

Everest's thinning glaciers: implications for tourism and mountaineering

Watson, C.S. and King, O. 2018.

  • Glacier mass loss in the Everest region of Nepal is accelerating in response to a warming climate, which is a trend observed across the central and eastern Himalaya.
  • We assess glacier accessibility, velocity, mass loss and collaborative opportunities between the scientific, local, and mountaineering communities.

The changing water cycle: the need for an integrated assessment of the resilience to changes in water supply in High-Mountain Asia

Quincey, D. Klaar, M. Haines, D. Lovett, J. Pariyar, B. Gurung, G. Brown, L. Watson, C.S. England, M. and Evans, B. 2018.

  • Water sourced from Asian mountains is vital to the survival of an estimated 1.4 billion people, but current and anticipated changes in snow, ice cover, and precipitation patterns may threaten these supplies and, in turn, the food security of tens of millions of people.
  • We outline how natural and social scientists as well as historians might work together to tackle the issues of changing water resources in South Asia, and the challenges that still need to be addressed for future water management.

Heterogeneous water storage and thermal regime of supraglacial ponds on debris-covered glaciers

Watson, C.S. Quincey, D.J. Carrivick, J.L. Smith, M.W. Rowan, A.V. and Richardson, R. 2017.

  • We used an unmanned surface vessel (USV) to collect sonar depth measurements for 24 ponds to derive the first empirical relationship between their area and volume applicable to the size distribution of ponds commonly encountered on debris‐covered glaciers.
  • We instrumented nine ponds with thermistors and three with pressure transducers, characterizing their thermal regime and capturing three pond drainage events.
  • Our observations of seasonal pond growth and drainage with their associated calculations of stored thermal energy have implications for glacier ice flow, the progressive enlargement and sudden collapse of englacial conduits, and the location of glacier ablation hot‐spots where ponds and ice cliffs interact.

Supraglacial Ponds Regulate Runoff From Himalayan Debris-Covered Glaciers

Irvine-Fynn, T.D.L. Porter, P.R. Rowan, A.V. Quincey, D.J. Gibson, M.J. Bridge, J.W. Watson, C.S. Hubbard, A. and Glasser, N.F. 2017.

  • We present a high‐resolution meltwater hydrograph from the extensively debris‐covered Khumbu Glacier, Nepal.
  • Supraglacial ponds and accompanying debris cover modulate proglacial discharge by acting as transient and evolving reservoirs.
  • Runoff regimes may become progressively buffered by the presence of supraglacial reservoirs.

Evaluating morphological estimates of the aerodynamic roughness of debris covered glacier ice

Quincey, D. Smith, M. Rounce, D. Ross, A. King, O. and Watson, C.S 2017.

  • We conducted structure from motion multi‐view stereo (SfM‐MVS) surveys across areas of the debris-covered Khumbu Glacier and calculated z0 using three previously published approaches.
  • The fully three‐dimensional cloud‐based approach is shown to be most stable across different scales and these z0 values are most correct in relative order when compared with wind tower data.

Quantifying ice cliff evolution with multi-temporal point clouds on the debris-covered Khumbu Glacier, Nepal

Watson, C.S. Quincey, D.J. Smith, M.W. Carrivick, J.L. Rowan, A.V. and James, M. 2017.

  • We used Structure from Motion photogrammetry with Multi-View Stereo to derive 3-D point clouds for nine ice cliffs on Khumbu Glacier, Nepal.
  • By differencing the point clouds, we could quantify the magnitude, seasonality and spatial variability of ice cliff retreat.

Identification of hazard and risk for glacial lakes in the Nepal Himalaya using satellite imagery from 2000–2015

Rounce, D. Watson, C.S. and McKinney, D. 2017.

  • This study identified 131 glacial lakes in Nepal in 2015 that are greater than 0.1 km2 and performed a first-pass hazard and risk assessment for each lake.
  • The hazard assessment included mass entering the lake, the moraine stability, and how lake expansion will alter the lake’s hazard in the next 15–30 years.
  • The results are intended to assist stakeholders and decision makers to determine the focus of future field studies, modeling efforts, and risk-mitigation actions.

Ice cliff dynamics in the Everest region of the Central Himalaya

Watson, C.S. Quincey, D.J. Carrivick, J.L. and Smith, M.W. 2017.

  • Ice cliffs predominantly had north-facing aspects independent of glacier flow direction, were positively correlated with glacier surface lowering, and were most prevalent in zones of active ice flow.
     

A new remote hazard and risk assessment framework for glacial lakes in the Nepal Himalaya

Rounce, D.R. McKinney, D.C. Lala, J.M. Byers, A.C. and Watson, C.S. 2016.

  • A remote sensing hazard assessment methodology was developed to assess the hazard and risk for glacial lakes in Nepal.

The dynamics of supraglacial ponds in the Everest region, central Himalaya

Watson, C.S. Quincey, D.J. Carrivick, J.L. and Smith, M.W. 2016

  • Large annual and inter-annual variation in pond area but some glaciers had increasing pond area, which has implications for glacial lake formation.
  • Coarser-resolution imagery cannot capture the pond size distributions encountered.

An improved method to represent DEM uncertainty in glacial lake outburst flood propagation using stochastic simulations

Watson, C.S. Carrivick, J. and Quincey, D. 2015.

  • Glacial lake outburst flood modelling techniques assessed for a catchment in Bhutan. A first-pass GIS-based assessment model is presented (Monte Carlo Least Cost Path - MC-LCP).

Glacier Movement

Watson, C.S and Quincey, D. 2015

  • A summary of techniques used to assess glacier movement such as feature tracking (using optical or radar imagery) and interferometric synthetic aperture radar (InSAR).