{"id":38786,"date":"2021-09-06T08:42:26","date_gmt":"2021-09-06T08:42:26","guid":{"rendered":"https:\/\/blogs.agu.org\/landslideblog\/?p=38786"},"modified":"2021-09-06T09:33:15","modified_gmt":"2021-09-06T09:33:15","slug":"catoca-mine-in-angola-using-satellite-imagery-to-understand-recent-events","status":"publish","type":"post","link":"https:\/\/blogs.agu.org\/landslideblog\/2021\/09\/06\/catoca-mine-in-angola-using-satellite-imagery-to-understand-recent-events\/","title":{"rendered":"Catoca mine in Angola – using satellite imagery to understand recent events"},"content":{"rendered":"

Catoca mine in Angola – using satellite imagery to understand recent events<\/h4>\n

According to Wikipedia, Catoca mine in Angola is the fourth largest diamond mine in the world<\/a>.\u00a0 Located at -9.399, 20.301, it consists of a big open cast pit and a very large tailings storage area.<\/p>\n

Last month, CRREBaC released information about a set of very significant pollution events in the rivers of Angola and Congo<\/a>, linked to mining in Angola.\u00a0 Reports have included the pollution of hundreds of kilometres of the river system, deaths of fish and hippos and, in some cases, suggestions of up to twelve fatalities<\/a>.\u00a0 Detailed information to evidence these huge losses is lacking, but there is little doubt that serious pollution occurred.<\/p>\n

Whilst this blog is about landslides, I have very often written (and indeed campaigned)\u00a0 about the scandalously poor management of tailings in the mining industry<\/a>, and I have highlighted several major tailings dam failures.\u00a0 My interest in the events in Angola and Congo results from concerns that the events might have been one or more tailings dam collapses.<\/p>\n

One of the candidate sites for the events in Angola is the facility at Catoca, and indeed the operators have reportedly admitted that a release did occur, but only of water and sand.<\/p>\n

This is a satellite image of the Catoca facility collected by Planet Labs<\/a> on 21 July 2021:-<\/p>\n

\"The

The Catoca diamond mine on 21 July 2021. Image copyright of Planet Labs<\/a>, used with permission.<\/p><\/div>\n

.<\/p>\n

The pit is in the bottom right hand corner, the tailings facility in the huge orange area on the left side of the image.\u00a0 The tailings dam is located just above the centre of the image, orientated NNW-SSE.\u00a0 There is no evidence of any problem in this image.<\/p>\n

The first sign of change appears in the image of 24 July 2021.\u00a0 The change is subtle but significant:-<\/p>\n

\"Pollution

Pollution downstream of the Catoca diamond mine on 24 July 2021. Image copyright of Planet Labs<\/a>, used with permission.<\/p><\/div>\n

.<\/p>\n

I have put a black circle around some clear pollution on the downstream side of the tailings dam.\u00a0 Note that the tailings dam was intact (and remains so).\u00a0 A day later the problems had become very much worse:-<\/p>\n

\"Pollution

Pollution downstream of the Catoca diamond mine on 25 July 2021. Image copyright of Planet Labs<\/a>, used with permission.<\/p><\/div>\n

.<\/p>\n

By 25 July 2021 a large plume of pollution had appeared on the downstream side of the tailings dam (highlighted with a circle again).\u00a0 The had entered the watercourse, which was now showing very clear signs of pollution (highlighted with an arrow).<\/p>\n

The situation today, a few weeks later, is interesting:-<\/p>\n

\"Pollution

Pollution downstream of the Catoca diamond mine on 5 September 2021. Image copyright of Planet Labs<\/a>, used with permission.<\/p><\/div>\n

.<\/p>\n

The plume has developed considerably , although it has not enlarged significantly (black circle).\u00a0 The polluted watercourse is very clear.\u00a0 There is clear evidence of works around the plume (new roads for example) and on the upstream side of the dam (white circle).<\/p>\n

From the images above the pollution might not at first sight look serious, but satellite images downstream might tell a different story.\u00a0 This image was collected on 25 July 2021 at about 8:56 UT, downstream of Catoca at -9.127, 20.346:-<\/p>\n

\"The

The front of the pollution downstream of the Catoca diamond mine on 25 July 2021. Image copyright of Planet Labs<\/a>, used with permission.<\/p><\/div>\n

.<\/p>\n

The river is flowing from the south to the north.\u00a0 In the lower part of the image the river is bright orange with pollution.\u00a0 In the northern part of the image the river is unpolluted.\u00a0 The marker, at -9.127, 20.346 is the approximate front of the pollution moving downstream from Catoca.\u00a0 Note the profound change in the water as the pollution front moves through.<\/p>\n

This is even more profoundly illustrated in the image below.\u00a0 The small tributary from Catoca flows in from the southwest.\u00a0 It meets the main channel, flowing from south to north.\u00a0 Note the huge change in water quality from this point onwards:-<\/p>\n

\"The

The passage of pollution downstream of the Catoca diamond mine on 25 July 2021. Image copyright of Planet Labs<\/a>, used with permission.<\/p><\/div>\n

.<\/p>\n

This location is -9.309, 20.362.<\/p>\n

According to the New York Times article<\/a>:-<\/p>\n

In a statement last month, the company admitted that there had been a \u201crupture in the pipeline that works as a spillway.\u201d\u00a0<\/em><\/p>\n

The satellite images are consistent with this as the source of the pollution, although the ecological damage looks to be more severe than some have suggested.<\/p>\n

However, there is an anomaly.\u00a0 The CRREBaC report indicates that substantial pollution was first seen in the rivers of Angola from 15 July 2021<\/a>:<\/p>\n

On the basis of the Sentinel images published by Visio Terra (Equipe Sentinel Vision, EVT919, 2021) and our preliminary investigations from riparian communities, this pollution has been observed since 15 July 2021 from the source in the Angola part of the basin and would have taken 15 days to reach the city of Tshikapa, and 21 days for the city of Ilebo in the Democratic Republic of the Congo (DRC). <\/em><\/p>\n

The pollution observed on 15 July 2021 does not seem to have come from Catoca according to the images, which suggests a second serious event occurred in a different mine in the area.<\/p>\n

.<\/p>\n

Reference<\/h4>\n

Planet Team (2021). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https:\/\/www.planet.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Catoca mine in Angola – using satellite imagery to understand recent events<\/p>\n","protected":false},"author":22,"featured_media":38801,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[27393],"tags":[85,30647,71,30646,299,205,29315,230],"class_list":["post-38786","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mining","tag-africa","tag-angola","tag-dam","tag-featureds","tag-mine","tag-mining","tag-pollution","tag-tailings"],"_links":{"self":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/38786","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=38786"}],"version-history":[{"count":0,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/posts\/38786\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media\/38801"}],"wp:attachment":[{"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/media?parent=38786"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/categories?post=38786"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.agu.org\/landslideblog\/wp-json\/wp\/v2\/tags?post=38786"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}