7 research outputs found
Use of LIDAR in landslide investigations: A review
This paper presents a short history of the appraisal of laser scanner
technologies in geosciences used for imaging relief by high-resolution
digital elevation models (HRDEMs) or 3D models. A general overview
of light detection and ranging (LIDAR) techniques applied to landslides
is given, followed by a review of different applications of LIDAR
for landslide, rockfall and debris-flow. These applications are classified
as: (1) Detection and characterization of mass movements; (2) Hazard
assessment and susceptibility mapping; (3) Modelling; (4) Monitoring.
This review emphasizes how LIDARderived HRDEMs can be used to investigate
any type of landslides. It is clear that such HRDEMs are not yet
a common tool for landslides investigations, but this technique has
opened new domains of applications that still have to be developed
Greenland surface mass balance simulated by a regional climate model and comparison with satellite derived data in 1990-1991
The 1990 and 1991 ablation seasons over Greenland are simulated with a coupled atmosphere-snow regional climate model with a 25-km horizontal resolution. The simulated snow water content allows a direct comparison with the satellite-derived melt signal. The model is forced with 6-hourly ERA-40 reanalysis at its boundaries. An evaluation of the simulated precipitation and a comparison of the modelled melt zone and the surface albedo with remote sensing observations are presented. Both the distribution and quantity of the simulated precipitation agree with observations from coastal weather stations, estimates from other models and the ERA-40 reanalysis. There are overestimations along the steep eastern coast, which are most likely due to the “topographic barrier effect”. The simulated extent and time evolution of the wet snow zone compare generally well with satellite-derived data, except during rainfall events on the ice sheet and because of a bias in the passive microwave retrieved melt signal. Although satellite-based surface albedo retrieval is only valid in the case of clear sky, the interpolation and the correction of these data enable us to validate the simulated albedo on the scale of the whole Greenland. These two comparisons highlight a large sensitivity of the remote sensing observations to weather conditions. Our high-resolution climate model was used to improve the retrieval algorithms by taking more fully into account the atmosphere variability. Finally, the good agreement of the simulated melting surface with the improved satellite signal allows a detailed estimation of the melting volume from the simulation
Monitoring elevation change of glaciers on Geladandong Mountain using TanDEM-X SAR interferometry
A review of recent developments in climate change science. Part I: Understanding of future change in the large-scale climate system
This article reviews some of the major lines of recent scientific progress relevant to the choice of global climate policy targets, focusing on changes in understanding since publication of the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4). Developments are highlighted in the following major climate system components: ice sheets; sea ice; the Atlantic Meridional Overturning Circulation; tropical forests; and accelerated carbon release from permafrost and ocean hydrates. The most significant developments in each component are identified by synthesizing input from multiple experts from each field. Overall, while large uncertainties remain in all fields, some substantial progress in understanding is revealed