scholarly journals Analysis of Desert Sand Dune Migration Patterns from Landsat Image Time Series for The Southern California Desert

2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Potter C
Keyword(s):  
Time Series ◽  
Southern California ◽  
Sand Dune ◽  
Landsat Image ◽  
Migration Patterns ◽  
Desert Sand ◽  
Dune Migration

The shape of desert sand dune grains

1981 ◽  
Vol 4 (3) ◽  
pp. 185-190 ◽  
Author(s):  
A.S. Goudie ◽  
A. Watson
Keyword(s):  
Sand Dune ◽  
Desert Sand

Sand Dune Migration Monitoring for Pipeline Hazard Risk Mitigation: The Peru LNG Coastal Section Case

2020 ◽  
Author(s):  
Fabien Ravet ◽  
Christian Silva ◽  
Rodolfo Gil ◽  
Simon Maguire ◽  
Etienne Rochat
Keyword(s):  
Early Detection ◽  
Natural Hazards ◽  
Sand Dune ◽  
Fiber Optic ◽  
Risk Mitigation ◽  
Third Party ◽  
Transport Systems ◽  
Geotechnical Monitoring ◽  
Dune Migration ◽  
Hydrocarbon Transport

Abstract Pipelines often cross challenging terrains where natural hazards are the main risk for their integrity. Environmental conditions can also worsen over the infrastructure lifetime. To reduce the risk of disasters, integrity programs are developed implementing tools for early detection of threats that can lead to a failure with dramatic social, environmental and economic consequences. Fiber optic (FO) monitoring solutions have been widely used and implemented as one of the most efficient prevention tools of these programs. These solutions include geotechnical monitoring, third party intrusion detection and eventually small or pinhole like leak detection. FO based geotechnical monitoring has been successfully operated along the Sierra section of the Peru LNG pipeline since 2010, detecting minor landslides and erosion events. It has also been implemented along other hydrocarbon transport systems to allow the early detection of such events. However, these natural hazards are not the only ones threatening the pipeline. In fact, the coastal section experiences other phenomenon such as sand dune migration and eolian erosion that put the pipeline at risk. Recently, the FO monitoring was extended to the coastal region using the existing communication fiber optic cable to sense temperature changes. Very localized events are thermally detected, their spatial and temporal signature analyzed. The comparison of this data with thermal models identified sections that are close to be exposed or whose soil cover is less than 50cm over a spatial extension that does not exceed a couple of meters. Depth of cover of 10 to 30cm is estimated from such analysis. These results are confirmed by past and ongoing site inspections. Such positive results again illustrate the potential value of fiber optic sensing to mitigate geohazard risks. It not only enhances the efficiency of the integrity program detecting and localizing threats, it also improves and rationalizes the maintenance activities as focused surveys can be conducted.

scholarly journals Preparing Landsat Image Time Series (LITS) for Monitoring Changes in Vegetation Phenology in Queensland, Australia

2012 ◽  
Vol 4 (6) ◽  
pp. 1856-1886 ◽  
Author(s):  
Santosh Bhandari ◽  
Stuart Phinn ◽  
Tony Gill
Keyword(s):  
Time Series ◽  
Landsat Image ◽  
Vegetation Phenology

scholarly journals Measuring Sand Dune Migration Rates with COSI-Corr and Landsat: Opportunities and Challenges

2019 ◽  
Vol 11 (20) ◽  
pp. 2423 ◽  
Author(s):  
Thomas Baird ◽  
Charlie Bristow ◽  
Pieter Vermeesch
Keyword(s):  
Sand Dune ◽  
Control Points ◽  
Migration Rates ◽  
Ground Control Points ◽  
Two Factors ◽  
Dune Migration ◽  
Level 1 ◽  
Bodele Depression ◽  
Processing Steps ◽  
Calculated Average

It has been over a decade since COSI-Corr, the Co-Registration of Optically Sensed Images and Correlation, was first used to produce a raster map of sand dune movement, however, no studies have yet applied it to the full Landsat archive. The orthorectified and geolocated Landsat Level-1 Precision Terrain (L1TP) products offer the opportunity to simplify the COSI-Corr pre-processing steps, allowing an automated workflow to be devised. In the Bodélé Depression, Chad, this automated workflow has calculated average dune speeds of 15.83 m/year and an increase in dune movement of 2.56 m/year ±12.58 m/year from 1987 to 2009. However, this increase does not stem from a systematic increase in dune mobility. The fastest 25% of dunes from 1987 to 1998 reduced their speed by 18.16%. The overall increase stems from the acceleration of features previously moving under 13.30 m/year. While successfully applied to the Bodélé Depression, the automated workflow produces highly variable outputs when applied to the Grand Erg Oriental, Algeria. Variations within path/row scene pairings are caused by the use of mobile features, such as dune crests, as ground control points (GCPs). This has the potential to warp Landsat scenes during the L1TP processing, potentially obfuscating dune migration. Two factors appear to be crucial in determining whether a Landsat scene is suitable for COSI-Corr analysis. Firstly, dune mobility must exceed the misregistration criteria. Secondly, GPCs should be located on static features such as bedrock outcrops.

scholarly journals Multi-fractal-interslipface angle curves of a morphologically simulated sand dune

2000 ◽  
Vol 5 (1) ◽  
pp. 71-74 ◽  
Author(s):  
B. S. Daya Sagar
Keyword(s):  
Remote Sensing ◽  
Time Series ◽  
Satellite Remote Sensing ◽  
Sand Dune ◽  
Fractal Dimensions ◽  
Morphological Transformation ◽  
Non Linear

A sand dune is simulated by means of a non-linear mathematical morphological transformation of which the fractal dimensions with corresponding interslipface angles are computed. This exercise has relevance to test the Validity of the model by considering various time series sand dune data that can be retrieved from the robust satellite remote sensing sensors.

scholarly journals The response of plant community diversity to alien invasion: evidence from a sand dune time series

2014 ◽  
Vol 24 (2) ◽  
pp. 371-392 ◽  
Author(s):  
Silvia Del Vecchio ◽  
Leonardo Pizzo ◽  
Gabriella Buffa
Keyword(s):  
Time Series ◽  
Plant Community ◽  
Sand Dune ◽  
Community Diversity ◽  
Alien Invasion

Link Between Long-Term Variability in Upwelling and Fish Production in the Northeast Pacific Ocean

1991 ◽  
Vol 48 (12) ◽  
pp. 2296-2306 ◽  
Author(s):  
Daniel M. Ware ◽  
Richard E. Thomson
Keyword(s):  
Time Series ◽  
Primary Production ◽  
Southern California ◽  
Coastal Upwelling ◽  
Pelagic Fish ◽  
Biological Time ◽  
Long Period ◽  
Pacific Sardine ◽  
The Individual

The biomass of pelagic fish in the Coastal Upwelling Domain off the west coast of North America decreased by a factor of 5 in the first half of this century. We assemble several physical and biological time series spanning this period to determine what may have caused this decline in productivity. Based on an observed link between time series of the coastal wind and primary production, we conclude that there was a strong relaxation in wind-induced upwelling and primary production between 1916 and 1942 off southern California. The fact that the individual biomasses of the dominant pelagic fish species tend to rise and fall in phase through the sediment record off southern California is consistent with our belief that these species are responding to a long-period (40–60 yr) oscillation in primary and secondary production, which, in turn, is being forced by a long-period oscillation in wind-induced upwelling. Our extended sardine recruitment time series indicates that there is a nonlinear relationship between Pacific sardine (Sardinops sagax) recruitment and upwelling and suggests that optimal recruitment occurs when the wind speed during the first few months of life averages 7–8 m/s.

Sign in / Sign up

Export Citation Format

Share Document