{"id":35740,"date":"2020-12-10T08:11:35","date_gmt":"2020-12-10T08:11:35","guid":{"rendered":"https:\/\/blogs.agu.org\/landslideblog\/?p=35740"},"modified":"2020-12-10T08:11:35","modified_gmt":"2020-12-10T08:11:35","slug":"mindu-1","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2020\/12\/10\/mindu-1\/","title":{"rendered":"Mindu in Tibet: detecting precursors of an imminent landslide"},"content":{"rendered":"<h4 class=\"hide-on-mobile hide-on-tablet\">Mindu in Tibet: detecting precursors of an imminent landslide<\/h4>\n<p>With the possible exception of some landslides triggered by earthquakes, large slope failures generally develop strain (movement) prior to failure.\u00a0 The failure process involves the progressive deformation of the slope &#8211; a shear surface may form in the base of the landslide, tension cracks form, lateral scarps develop, etc.\u00a0 <a href=\"https:\/\/blogs.agu.org\/landslideblog\/2020\/05\/15\/barry-glacier-rock-slope-1\/\">A classic case is the Barry Arm landslide in Alaska<\/a>, where movement on the slope has led to the development of very large tension cracks.\u00a0 There is strong evidence that over time the rate of movement increases as failure approaches.\u00a0 This increase in deformation is the basis of various methods of <a href=\"https:\/\/blogs.agu.org\/landslideblog\/2013\/04\/12\/the-unusually-large-bingham-canyon-mine-landslide-an-impressive-example-of-prediction-using-monitoring\/\">prediction of the time of failure (with success in some circumstances)<\/a>.<\/p>\n<p>One challenge of course is to use this knowledge to identify and monitor slopes that might be undergoing failure.\u00a0 The holy grail is to have a remote monitoring system that collects data at a regional or national scale and then identifies slopes that are actively deforming.\u00a0 <a href=\"https:\/\/blogs.agu.org\/landslideblog\/?s=insar&amp;submit.x=0&amp;submit.y=0&amp;mswhere=blog\">InSAR<\/a> provides one potential basis for this, and <a href=\"https:\/\/blogs.agu.org\/landslideblog\/2018\/12\/13\/insarnorway-1\/\">national scale deformation maps are now available<\/a>, but identifying correctly slopes that might be dangerous requires more work and a better understanding.<\/p>\n<p>Another approach, applicable for individual landslides at the moment, is to use imaged correlation approaches from optical satellite imagery.\u00a0 In this approach, pairs of images are compared. Perhaps surprisingly, image processing can allows deformations on the scale of 3 to 10% of a pixel to be detected.\u00a0 The Sentinel-2 satellites have an image resolution of about 10 metres, so deformation of less than a metre can be measured.<\/p>\n<p>In an open access paper in the journal <a href=\"https:\/\/www.natural-hazards-and-earth-system-sciences.net\/\"><em>Natural Hazards and Earth System Sciences<\/em><\/a>, <a href=\"https:\/\/nhess.copernicus.org\/articles\/20\/3215\/2020\/\">Yang <em>et al.<\/em> (2020)<\/a> have used image processing of Sentinel-2 imagery to examine the movement through time of a developing failure near to the town of Mindu in Tibet.\u00a0 This is a large area of slope deformation &#8211; this is the Google earth image collected in 2011 for example:-<\/p>\n<div id=\"attachment_35743\" style=\"width: 810px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-35743\" class=\" wp-image-35743\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2020\/12\/20_12-Mindu-1.jpg\" alt=\"The landslide near to Mindu in Tibet\" width=\"800\" height=\"505\" srcset=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2020\/12\/20_12-Mindu-1.jpg 1284w, https:\/\/blogs.agu.org\/landslideblog\/files\/2020\/12\/20_12-Mindu-1-300x189.jpg 300w, https:\/\/blogs.agu.org\/landslideblog\/files\/2020\/12\/20_12-Mindu-1-1024x647.jpg 1024w, https:\/\/blogs.agu.org\/landslideblog\/files\/2020\/12\/20_12-Mindu-1-768x485.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><p id=\"caption-attachment-35743\" class=\"wp-caption-text\">A Google Earth image of the landslide near to Mindu in Tibet.<\/p><\/div>\n<p>.<\/p>\n<p>The location of this landslide is 30.582, 98.925.\u00a0 Whilst there is little in the way of the landslide, clearly a major rock slope failure at this site near to Mindu would potentially\u00a0 block the river, creating a substantial hazard downstream.<\/p>\n<p>The image processing by <a href=\"https:\/\/nhess.copernicus.org\/articles\/20\/3215\/2020\/\">Yang <em>et al.<\/em> (2020)<\/a> has demonstrated that this landslide is actively deforming.\u00a0 Perhaps most interestingly, between November 2015 and November 2018 the slope showed less than 2 metres of movement. However, between 2018 and 209 the slope moved over 6 metres.\u00a0 The research team were able to then look at a larger number of images in this more rapid movement period, finding that in the rainy season (summer and autumn) the movement rate accelerated.<\/p>\n<p>This study demonstrates that processing of optical satellite imagery can allow high quality monitoring of dangerous slopes to be undertaken. It is another step along the way towards the goal of high quality early warning systems for slopes in high mountain areas.<\/p>\n<h4>Reference<\/h4>\n<div class=\"citation-footer-content hide-on-mobile-soft show-no-js\">\n<div class=\"grid-container citation-footer \">Yang, W., Liu, L., and Shi, P. 2020. <a href=\"https:\/\/nhess.copernicus.org\/articles\/20\/3215\/2020\/\">Detecting precursors of an imminent landslide along the Jinsha River<\/a>.\u00a0 <em>Natural Hazards and Earth System Sciences<\/em>, <strong>20<\/strong>, 3215\u20133224, <a href=\"https:\/\/doi.org\/10.5194\/nhess-20-3215-2020\">https:\/\/doi.org\/10.5194\/nhess-20-3215-2020<\/a>.<\/div>\n<\/div>\n<!-- AddThis Advanced Settings generic via filter on the_content --><!-- AddThis Share Buttons generic via filter on the_content -->","protected":false},"excerpt":{"rendered":"<p> Mindu in Tibet: a new open access paper in the journal Natural Hazards and Earth System Sciences explores the detection of precursors of an imminent landslide using satellite images<!-- AddThis Advanced Settings generic via filter on wp_trim_excerpt --><!-- AddThis Share Buttons generic via filter on wp_trim_excerpt --><\/p>\n","protected":false},"author":22,"featured_media":35743,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[561],"tags":[881,469,39,192,17,113],"class_list":["post-35740","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-monitoring-2","tag-east-asia","tag-featured","tag-monitoring","tag-paper","tag-research","tag-tibet"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/35740","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/users\/22"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/comments?post=35740"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/35740\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/35743"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=35740"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=35740"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=35740"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}