Monitoring marginal erosion in hydroelectric reservoirs with terrestrial mobile laser scanner

Abstract

ABSTRACT:Marginal erosions in reservoirs of hydroelectric plants have caused economic and environmental problems concerning hydroelectric power generation, reduction of productive areas and devaluing land parcels. The real extension and dynamics of these erosion processes are not well known for Brazilian reservoirs. To objectively assess these problems Unesp (Univ Estadual Paulista) and Duke Energy are developing a joint project which aims at the monitoring the progression of some erosive processes and understanding the causes and the dynamics of this phenomenon. Mobile LASER scanning was considered the most suitable alternative for the challenges established in the project requirements. A MDL DynaScan Mobile LASER M150 scanner was selected which uses RTK for real time positioning integrated to an IMU, enabling instantaneous generation of georeferenced point clouds. Two different reservoirs were choose for monitoring: Chavantes (storage plant) and Rosana (run-of-river plant), both in the Paranapanema River, border of São Paulo and Paraná States, Brazil. The monitoring areas are scanned quarterly and analysed with base on the point cloud, meshes, contours and cross sections. Cross sections are used to visualize and compute the rate and the dynamics of erosion. Some examples and quantitative results are presented along with an analysis of the proposed technique. Some recommendations to improve the field work and latter data processing are also introduced.

Evaluation of Long-Range Mobile Mapping System (MMS) and Close-Range Photogrammetry for Deformation Monitoring. A Case Study of Cortes de Pallás in Valencia (Spain)

“…The light weight of these MLSs makes them flexible and versatile instruments, so they can be mounted on any mobile platform. In places with complex topography, the use of MMS, following a continuous path, is more advantageous than a tripod-based laser scanner that requires multiple scan positions to cover all the areas of the survey [6]. Moreover, integrating MMS with other geomatics techniques, such as Digital Photogrammetry (DP), allows giving an added value and greater richness of the acquired data providing a high detailed DEM or DTM (Digital Terrain Model) of the selected area [8].…”

“…A boat-based MMS was selected by Brazilian researchers to scan the progression of marginal erosion in different reservoirs of hydroelectric plants. The processed point clouds and rendered meshes and the creation of cross-sections were used to compute the rate and the dynamics of the erosion phenomenon [6,22].…”

“…Where a topographic survey is based on limited distances (e.g., tens to hundreds of meters), it has historically been carried out with total stations. Although such method provides high accuracy and precision for the measurement of individual points, significant time is required to collect a sufficient density of data to produce rough landscape Digital Elevation Models (DEMs) [6]. Laser Scanning (LS) and Close-Range Photogrammetry (CRP) are state of the art techniques for acquiring dense and precise topographic data at the output detail, for accurate volume measurements or modeling.…”

Monitoring Bank Erosion in Hydroelectric Reservoirs With Mobile Laser Scanning

“…The hydroelectric plant reservoir is formed by the Paranapanema River, which creates the border of São Paulo and Paraná States. The reservoir has an area of approximately 400 km 2 with a perimeter of 1085 km [15]. Hundreds of eroded regions can be identified on the banks of the reservoir.…”

Close-Range Photogrammetric Techniques for Deformation Measurement: Applications to Landslides

“…In order of relevance, the paramount role is taken by terrestrial laser scanning (TLS) (see for example, Bitelli et al (2004), Guffar et al (2013), and Barbarella et al (2014)). A few experiences with laser scanning systems implemented in terrestrial mobile vehicles (mobile laser scanning-MLS) have been also reported in De Agostino et al (2012) and Tommaselli et al (2014). The advantage of laser scanning techniques is they may directly provide a dense point cloud describing the topographic ground or vertical rock faces (see Abellán et al (2014)).…”