標題: Quantifying sediment mass redistribution from joint time-lapse gravimetry and photogrammetry surveys
作者: Mouyen, Maxime
Steer, Philippe
Chang, Kuo-Jen
Le Moigne, Nicolas
Hwang, Cheinway
Hsieh, Wen-Chi
Jeandet, Louise
Longuevergne, Laurent
Cheng, Ching-Chung
Boy, Jean-Paul
Masson, Frederic
土木工程學系
Department of Civil Engineering
公開日期: 22-六月-2020
摘要: The accurate quantification of sediment mass redistribution is central to the study of surface processes, yet it remains a challenging task. Here we test a new combination of terrestrial gravity and drone photogrammetry methods to quantify sediment mass redistribution over a 1 km(2) area. Gravity and photogrammetry are complementary methods. Indeed, gravity changes are sensitive to mass changes and to their location. Thus, by using photogrammetry data to constrain this location, the sediment mass can be properly estimated from the gravity data. We carried out three joint gravimetry-photogrammetry surveys, once a year in 2015, 2016 and 2017, over a 1 km(2) area in southern Taiwan, featuring both a wide meander of the Laonong River and a slow landslide. We first removed the gravity changes from non-sediment effects, such as tides, groundwater, surface displacements and air pressure variations. Then, we inverted the density of the sediment with an attempt to distinguish the density of the landslide from the density of the river sediments. We eventually estimate an average loss of 3.7 +/- 0.4 x 10(9) kg of sediment from 2015 to 2017 mostly due to the slow landslide. Although the gravity devices used in this study are expensive and need week-long surveys, new instrumentation currently being developed will enable dense and continuous measurements at lower cost, making the method that has been developed and tested in this study well-suited for the estimation of erosion, sediment transfer and deposition in landscapes.
URI: http://dx.doi.org/10.5194/esurf-8-555-2020
http://hdl.handle.net/11536/154988
ISSN: 2196-6311
DOI: 10.5194/esurf-8-555-2020
期刊: EARTH SURFACE DYNAMICS
Volume: 8
Issue: 2
起始頁: 555
結束頁: 577
顯示於類別:期刊論文