{"id":44268,"date":"2023-07-25T06:58:28","date_gmt":"2023-07-25T06:58:28","guid":{"rendered":"https:\/\/blogs.agu.org\/landslideblog\/?p=44268"},"modified":"2023-07-25T06:58:28","modified_gmt":"2023-07-25T06:58:28","slug":"ungar-1","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2023\/07\/25\/ungar-1\/","title":{"rendered":"The location of the 20 July 2023 debris flow at Ungar in Lhuentse, Bhutan"},"content":{"rendered":"<h4>The location of the 20 July 2023 debris flow at Ungar in Lhuentse, Bhutan<\/h4>\n<p>Yesterday, <a href=\"https:\/\/blogs.agu.org\/landslideblog\/2023\/07\/24\/an-update-on-the-19-july-2023-irshalwadi-landslide-and-a-catastrophic-debris-flow-in-bhutan\/\">I posted about a debris flow disaster that occurred on 20 July 2023 at Ungar (also spelt Unger and Unngar) in Bhutan<\/a>, which is believed to have killed 23 people.\u00a0 <a href=\"https:\/\/www.ncl.ac.uk\/gps\/staff\/profile\/stuartdunning.html\">Dr Stuart Dunning<\/a> (<a href=\"https:\/\/twitter.com\/Rock_Avalanches\">@Rock_Avalanches<\/a>) of the Newcastle University tweeted (or is that Xeeted?) a possible location for the accident, based upon <a href=\"https:\/\/www.planet.com\/\">Planet Labs images<\/a>:-<\/p>\n<blockquote class=\"twitter-tweet\" data-width=\"500\" data-dnt=\"true\">\n<p lang=\"en\" dir=\"ltr\">Ungar, Bhutan debris flow <a href=\"https:\/\/twitter.com\/davepetley?ref_src=twsrc%5Etfw\">@davepetley<\/a> ? Right is June, left is July 22nd <a href=\"https:\/\/twitter.com\/KuenselOnline?ref_src=twsrc%5Etfw\">@KuenselOnline<\/a> <a href=\"https:\/\/twitter.com\/glof_Sonam?ref_src=twsrc%5Etfw\">@glof_Sonam<\/a> <a href=\"https:\/\/t.co\/CjQErRNXEs\">pic.twitter.com\/CjQErRNXEs<\/a><\/p>\n<p>&mdash; Stuart Dunning (@Rock_Avalanches) <a href=\"https:\/\/twitter.com\/Rock_Avalanches\/status\/1683444158457937925?ref_src=twsrc%5Etfw\">July 24, 2023<\/a><\/p><\/blockquote>\n<p><script async src=\"https:\/\/platform.twitter.com\/widgets.js\" charset=\"utf-8\"><\/script><\/p>\n<p>.<\/p>\n<p>This location is [27.57095, 91.07595]. Looking at the photographs of the site, I think that this is indeed the location.\u00a0 This is a <a href=\"https:\/\/www.planet.com\/\">Planet<\/a> image of the site collected on 15 July 2023:-<\/p>\n<div id=\"attachment_44271\" style=\"width: 810px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-44271\" class=\"wp-image-44271\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-2.jpg\" alt=\"The site of the 20th July 2023 debris flow at Ungar in Bhutan. \" width=\"800\" height=\"460\" srcset=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-2.jpg 1312w, https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-2-300x172.jpg 300w, https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-2-1024x588.jpg 1024w, https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-2-768x441.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><p id=\"caption-attachment-44271\" class=\"wp-caption-text\"><em>The site of the 20th July 2023 debris flow at Ungar in Bhutan. Image copyright <a href=\"https:\/\/www.planet.com\/\">Planet<\/a>, used with permission. Image dated 15 July 2023.<\/em><\/p><\/div>\n<p>.<\/p>\n<p>This is an image collected on 22 July 2023, showing the aftermath of the debris flow:-<\/p>\n<div id=\"attachment_44273\" style=\"width: 810px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-44273\" class=\"wp-image-44273\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-3.jpg\" alt=\"The aftermath of the 20th July 2023 debris flow at Ungar in Bhutan.\" width=\"800\" height=\"464\" srcset=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-3.jpg 1313w, https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-3-300x174.jpg 300w, https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-3-1024x594.jpg 1024w, https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-3-768x446.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><p id=\"caption-attachment-44273\" class=\"wp-caption-text\"><em>The aftermath of the 20th July 2023 debris flow at Ungar in Bhutan. Image copyright <a href=\"https:\/\/www.planet.com\/\">Planet<\/a>, used with permission. Image dated 22 July 2023.<\/em><\/p><\/div>\n<p>.<\/p>\n<p>Below is a slider that should allow you to compare the two images:<\/p>\n<div class=\"juxtapose\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-2.jpg\" alt=\"The site of the 20th July 2023 debris flow at Ungar in Bhutan. \" width=\"800\" height=\"460\" \/><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-3.jpg\" alt=\"The aftermath of the 20th July 2023 debris flow at Ungar in Bhutan.\" width=\"800\" height=\"460\" \/><\/div>\n<p>.<\/p>\n<p>In the image before the disaster, there appears to be a set of structures in the channel immediately below the confluence of the two tributaries. In the image after the debris flow, these structures have clearly been destroyed. The decision to locate a camp, if that is what happened, in such a vulnerable position is interesting. As I noted previously, there are multiple examples in which landslide hazard has not been properly considered in hydroelectric schemes in the Himalayas.<\/p>\n<p>The source area for the debris flow, to the west of the images above, is shrouded in cloud in the images since the accident.\u00a0 However, this is what the catchment looks like on Google Earth &#8211; the pin is the location of the camp:-<\/p>\n<div id=\"attachment_44277\" style=\"width: 810px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-44277\" class=\"wp-image-44277\" src=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-4.jpg\" alt=\"Google Earth image showing the catchment of the 20 July 2023 debris flow at Ungar in Bhutan.\" width=\"800\" height=\"527\" srcset=\"https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-4.jpg 1450w, https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-4-300x198.jpg 300w, https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-4-1024x675.jpg 1024w, https:\/\/blogs.agu.org\/landslideblog\/files\/2023\/07\/23_07-Unger-4-768x506.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><p id=\"caption-attachment-44277\" class=\"wp-caption-text\"><em>Google Earth image showing the catchment of the 20 July 2023 debris flow at Ungar in Bhutan.<\/em><\/p><\/div>\n<p>.<\/p>\n<p>This is clearly a very steep, dissected landscape, with multiple small tributaries feeding into the main channel. This is a classic for landscape for small slips combining to create a channelised debris flow. Unfortunately, cloud free images may not become available until the end of the monsoon.<\/p>\n<p>.<\/p>\n<h4>Acknowledgement<\/h4>\n<p>Planet Team (2023). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. <a href=\"https:\/\/www.planet.com\/\">https:\/\/www.planet.com\/<\/a><\/p>\n<!-- AddThis Advanced Settings generic via filter on the_content --><!-- AddThis Share Buttons generic via filter on the_content -->","protected":false},"excerpt":{"rendered":"<p>Thanks to @Rock_Avalanches and @Planet, the location of the 20 July 2023 debris flow at Ungar in Lhuentse, Bhutan has now been identified.<!-- 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":44273,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7203],"tags":[559,469,959,898,1205,25,72],"class_list":["post-44268","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-planet-labs","tag-bhutan","tag-featured","tag-landslide-report","tag-planet","tag-planet-labs","tag-satellite","tag-south-asia"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/44268","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=44268"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/44268\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/44273"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=44268"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=44268"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=44268"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}