Application of Persistent Scatterer Interferometry (PSI) in monitoring slope movements in Nainital, Uttarakhand Lesser Himalaya, India

Abstract

Orogenic movements and subtropical climate have rendered the slopes of the Himalayan region intensely deformed and weathered. As a result, the incidences of slope failure are quite common all along the Himalayan region. The Lesser Himalayan terrane is particularly vulnerable to mass-movements owing to geological fragility, and many parts of it are bearing a high-risk of associated disaster owing to the high population density. An important step towards mitigation of such disasters is the monitoring of slope movement. Towards this, the Persistent Scatterer Interferometry (PSI) technique can be applied. In the present study, the PSI technique is employed in Lesser Himalayan town of Nainital in Uttarakhand state of India to decipher and monitor slope movements. A total of 15 multi-date ENVISAT ASAR satellite images, acquired during August 2008 to August 2010 period, were subjected to PSI, which revealed a continuous creep movement along the hillslopes located towards the eastern side of the Nainital lake. The higher reaches of the hill seem to be experiencing accelerated creep of ∼21 mm/year, which decreases downslope to ∼5 mm/year. Based on spatial pattern of varying PSI Mean LOS Velocity (MLV) values, high (H), moderate (M), low (L) and very low (S) creeping zones have been delineated in the hillslopes. Given the long history of mass movements and continuously increasing anthropogenic activities in Nainital, these results call for immediate measures to avert any future disaster in the town.

Técnica PSInSAR na Avaliação de Deslocamentos: Análise Conceitual, Aplicações e Perspectivas

“…Ferretti et al (2000Ferretti et al ( , 2001 desenvolveram a técnica PSInSAR™ a qual foi pioneira na solução completa para selecionar pixels com Dispersores Persistentes (do inglês Persistent Scatterer -PS). Um PS, de acordo com Yhokha et al (2018), são elementos que apresentam um retroespalhamento estáveis ao longo do tempo (e.g. casas, prédios, pontes, rochas, etc.).…”

Rainfall Induced Landslide Studies in Indian Himalayan Region: A Critical Review

“…In the case of Indian Himalaya, monitoring studies include remote sensing techniques and ground based observation. Yhokha et al [56] used the Persistent Scatterer Interferometry (PSI) technique using ENVISAT satellite for Lesser Himalaya, Nainital. PSI is based on InSAR technique, which utilizes several SAR images and has proved to be successful in identifying the creeping zones in Nainital.…”

Aplicación del método Persistent Scatterer Interferometry (PSI) en la ciudad de Limón, Costa Rica

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