Glacier change and glacial lake outburst flood risk in the Bolivian Andes

Glaciers of the Bolivian Andes represent an important water resource for Andean cities and mountain communities, yet relatively little work has assessed changes in their extent over recent decades. In many mountain regions, glacier recession has been accompanied by the development of proglacial lakes, which can pose a glacial lake outburst flood (GLOF) hazard. However, no studies have assessed the development of such lakes in Bolivia despite recent GLOF incidents here. Our mapping from satellite imagery reveals an overall areal shrinkage of 228.1 ± 22.8 km2 (43.1 %) across the Bolivian Cordillera Oriental between 1986 and 2014. Shrinkage was greatest in the Tres Cruces region (47.3 %), followed by the Cordillera Apolobamba (43.1 %) and Cordillera Real (41.9 %). A growing number of proglacial lakes have developed as glaciers have receded, in accordance with trends in most other deglaciating mountain ranges, although the number of ice-contact lakes has decreased. The reasons for this are unclear, but the pattern of lake change has varied significantly throughout the study period, suggesting that monitoring of future lake development is required as ice continues to recede. Ultimately, we use our 2014 database of proglacial lakes to assess GLOF risk across the Bolivian Andes. We identify 25 lakes that pose a potential GLOF threat to downstream communities and infrastructure. We suggest that further studies of potential GLOF impacts are urgently required

Landslide Susceptibility Map of Johnson County, Kentucky

The purpose of this map is to identify landslide-prone areas in Johnson County in order to provide the public, as well as local and state government agencies, with information about where landslides are likely to occur. This map represents geomorphic-based susceptibility modeling that focuses on physical slope characteristics and morphology, the quality of which is dependent on data accuracy and resolution of terrain models. The availability of high-resolution (5-ft digital elevation model) lidar derived datasets allows for the generation of terrain elevation derivatives such as hillshades, slope, aspect, curvature, and roughness, as well as identification of existing landslide deposits. These high-resolution lidar derived datasets, coupled with landslide inventory mapping, enable us to produce detailed, high-resolution landslide susceptibility maps

Landslide Susceptibility Map of Pike County, Kentucky

The purpose of this map is to identify landslide-prone areas in Pike County in order to provide the public, as well as local and state government agencies, with information about where landslides are likely to occur. This map represents geomorphic-based susceptibility modeling that focuses on physical slope characteristics and morphology, the quality of which is dependent on data accuracy and resolution of terrain models. The availability of high-resolution (5-ft digital elevation model) lidar derived datasets allows for the generation of terrain elevation derivatives such as hillshades, slope, aspect, curvature, and roughness, as well as identification of existing landslide deposits. These high-resolution lidar derived datasets, coupled with landslide inventory mapping, enable us to produce detailed, high-resolution landslide susceptibility maps

Landslide Susceptibility Map of Martin County, Kentucky

The purpose of this map is to identify landslide-prone areas in Martin County in order to provide the public, as well as local and state government agencies, with information about where landslides are likely to occur. This map represents geomorphic-based susceptibility modeling that focuses on physical slope characteristics and morphology, the quality of which is dependent on data accuracy and resolution of terrain models. The availability of high-resolution (5-ft digital elevation model) lidar derived datasets allows for the generation of terrain elevation derivatives such as hillshades, slope, aspect, curvature, and roughness, as well as identification of existing landslide deposits. These high-resolution lidar derived datasets, coupled with landslide inventory mapping, enable us to produce detailed, high-resolution landslide susceptibility maps

Landslide Susceptibility Map of Floyd County, Kentucky

The purpose of this map is to identify landslide-prone areas in Floyd County in order to provide the public, as well as local and state government agencies, with information about where landslides are likely to occur. This map represents geomorphic-based susceptibility modeling that focuses on physical slope characteristics and morphology, the quality of which is dependent on data accuracy and resolution of terrain models. The availability of high-resolution (5-ft digital elevation model) lidar derived datasets allows for the generation of terrain elevation derivatives such as hillshades, slope, aspect, curvature, and roughness, as well as identification of existing landslide deposits. These high-resolution lidar derived datasets, coupled with landslide inventory mapping, enable us to produce detailed, high-resolution landslide susceptibility maps

Modelling glacial lake outburst flood impacts in the Bolivian Andes

The Bolivian Andes have experienced sustained and widespread glacier mass loss in recent decades. Glacier recession has been accompanied by the development of proglacial lakes, which pose a glacial lake outburst flood (GLOF) risk to downstream communities and infrastructure. Previous research has identified three potentially dangerous glacial lakes in the Bolivian Andes, but no attempt has yet been made to model GLOF inundation downstream from these lakes. We generated 2-m resolution DEMs from stereo and tri-stereo SPOT 6/7 satellite images to drive a hydrodynamic model of GLOF flow (HEC-RAS 5.0.3). The model was tested against field observations of a 2009 GLOF from Keara, in the Cordillera Apolobamba, and was shown to reproduce realistic flood depths and inundation. The model was then used to model GLOFs from Pelechuco lake (Cordillera Apolobamba) and Laguna Arkhata and Laguna Glaciar (Cordillera Real). In total, six villages could be affected by GLOFs if all three lakes burst. For sensitivity analysis, we ran the model for three scenarios (pessimistic, intermediate, optimistic), which give a range of ~ 1100 to ~ 2200 people affected by flooding; between ~ 800 and ~ 2100 people could be exposed to floods with a flow depth ≥ 2 m, which could be life threatening and cause a significant damage to infrastructure. We suggest that Laguna Arkhata and Pelechuco lake represent the greatest risk due to the higher numbers of people who live in the potential flow paths, and hence, these two glacial lakes should be a priority for risk managers

Landslide Susceptibility Map of Magoffin County, Kentucky

The purpose of this map is to identify landslide-prone areas in Magoffin County, Kentucky, in order to provide the public, as well as local and state government agencies, with information about where landslides are likely to occur. This map represents geomorphic-based susceptibility modeling that focuses on physical slope characteristics and morphology, the quality of which is dependent on data accuracy and resolution of terrain models. The availability of high-resolution (5-ft digital elevation model) lidar derived datasets allows for the generation of terrain elevation derivatives such as hillshades, slope, aspect, curvature, and roughness, as well as identification of existing landslide deposits. These high-resolution lidar derived datasets, coupled with landslide inventory mapping, enable us to produce detailed, high-resolution landslide susceptibility maps

Reconnaissance of Landslides and Debris Flows Associated with the July 2022 Flooding in Eastern Kentucky

Between July 25 and July 30, 2022, a series of convective storms generated approximately 14–16 inches of rainfall across parts of eastern Kentucky, predominately in Clay, Leslie, Perry, Breathitt, Knott, and Letcher Counties. The peak rainfall occurred on the evening of July 27 and the morning of July 28, with the hardest-hit areas experiencing more than 10 inches in a 24-hour period. The historic rainfall led to catastrophic flooding along many rivers and streams, but also triggered widespread landslides and debris flows that damaged roads, homes, property, and other infrastructure. Once initial relief and recovery efforts were established, the Kentucky Geological Survey (KGS) geohazard section conducted a preliminary field reconnaissance that observed and documented landslides and debris flows triggered by the July storm event. We documented landslides from late August to early November 2022 using (1) visual field inspection methods and (2) a remote sensing technique called normalized differencing vegetation index (NDVI). Visual field inspection occurred primarily along roads through documentation of landslide type and location. The NDVI technique allowed identification of larger landslides and debris flows not easily accessible in a vehicle. We identified more than 1,000 new landslides and debris flows triggered by the July event. The majority of landslides the team identified were shallow translational slides, supplemented by some rotational slides (slumps), and debris flows. Documenting landslides in the field before they perish is important for future hazard assessment modeling. Landslide inventories associated with large storm events, and large impact areas, will improve our understanding of landslide occurrence and rainfall rates, and potentially our ability to forecast landslides. The data is intended for use by both scientists and non-scientists, such as emergency managers and public safety decision-makers