{"id":52894,"date":"2025-09-02T20:36:24","date_gmt":"2025-09-02T15:06:24","guid":{"rendered":"https:\/\/www.nextias.com\/ca\/?p=52894"},"modified":"2025-09-08T11:09:15","modified_gmt":"2025-09-08T05:39:15","slug":"why-some-rivers-stay-single","status":"publish","type":"post","link":"https:\/\/www.nextias.com\/ca\/current-affairs\/02-09-2025\/why-some-rivers-stay-single","title":{"rendered":"Why Some Rivers Stay Single While Others Split?"},"content":{"rendered":"\n<p><strong>Syllabus: GS1\/ Geography<\/strong><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Context<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Researchers at the University of California, analysed 36 years of satellite data across 84 rivers worldwide to identify why some rivers maintain a single-thread channel, while others develop into braided or multi-thread systems.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Fluvial Processes and Channel Types<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Rivers are broadly classified<\/strong> as single-thread or multi-thread (braided\/ anastomosing).&nbsp;<\/li>\n\n\n\n<li><strong>In a single-thread river<\/strong>, lateral <strong>erosion of one bank<\/strong> is roughly<strong> matched <\/strong>by <strong>sediment deposition<\/strong> on the opposite bank.\n<ul class=\"wp-block-list\">\n<li>This balance keeps the channel width constant and lets the river meander across its floodplain.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Multi-threaded rivers<\/strong> occur where <strong>bank erosion exceeds deposition<\/strong>.\n<ul class=\"wp-block-list\">\n<li>The extra sediment eroded from the banks accumulates mid-channel as bars and islands, forcing the flow to<strong> split into multiple shallow threads.<\/strong><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Factors influencing erosion and deposition balance<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Slope and discharge:<\/strong> Steeper slopes and high flows increase stream power, promoting bank erosion. Multi-thread channels \u201cfavour higher water discharge, coarser sediment, and steeper slopes\u201d\n<ul class=\"wp-block-list\">\n<li>Many Himalayan and volcanic rivers are braided for these reasons.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Sediment size and load:<\/strong> Rivers carrying a lot of coarse sediment (gravel, sand) tend to overload their channels and deposit bars, triggering braiding.&nbsp;<\/li>\n\n\n\n<li><strong>Vegetation and bank material:<\/strong> Stable, vegetated banks <strong>resist erosion<\/strong> and encourage single channels.&nbsp;<\/li>\n\n\n\n<li><strong>Human interventions:<\/strong> Dams, embankments and channelization <strong>constrain a braided river into one thread.<\/strong> In fact, many rivers that are single-thread today were braided before human interference<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Examples of river braiding<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Amazon River (South America):<\/strong> Mostly <strong>single-threaded<\/strong> due to fine sediment and strong bank vegetation.<\/li>\n\n\n\n<li><strong>Mississippi River (USA): <\/strong>Meandering single channel, controlled by fine sediment and engineering works.<\/li>\n\n\n\n<li><strong>Indian rivers:<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Ganga in Plains: <\/strong>Single-thread with meandering, due to fine alluvium and flat topography.<\/li>\n\n\n\n<li><strong>Brahmaputra in Assam: <\/strong>Multi-thread braided system, leading to frequent floods and erosion.<\/li>\n\n\n\n<li><strong><a href=\"https:\/\/www.nextias.com\/ca\/current-affairs\/30-05-2022\/kosi-river\" data-type=\"link\" data-id=\"https:\/\/www.nextias.com\/ca\/current-affairs\/30-05-2022\/kosi-river\">Kosi River (Bihar)<\/a>:<\/strong> Known as the \u201cSorrow of Bihar\u201d because its unstable, sediment-heavy channels keep shifting.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Significance of the Study<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The study helps<strong> predict flood risks<\/strong> in braided river regions, providing insights for disaster management, especially in flood-prone states like Assam and Bihar.\n<ul class=\"wp-block-list\">\n<li><strong>Braided rivers<\/strong> constantly <strong>shuffle their channels,<\/strong> changing course across the floodplain. This makes them <strong>dynamic and unpredictable.<\/strong><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>It is useful in <strong>river engineering projects <\/strong>such as dams, barrages, and embankments.<\/li>\n\n\n\n<li>It assists in <strong>environmental conservation<\/strong>, since river splitting affects wetlands, fisheries, and livelihoods.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-background has-fixed-layout\" style=\"background-color:#fff2cc\"><tbody><tr><td><strong>What are Meanders?<\/strong><br>&#8211; Meanders are large bends or curves in the<strong> middle and lower course<\/strong> of a river, formed due to both erosion and deposition processes.<br>&#8211; A meander is formed when the <strong>water flow velocity diminishes in the river, <\/strong>reducing its ability to cut downwards. Instead, it begins to erode laterally (sideways).<br>1. <strong>On the outer concave bank<\/strong>, the river\u2019s current is stronger, causing erosion.<br>2. <strong>On the inner convex bank<\/strong>, the current is weaker, leading to deposition of sediments (point bars).<br>&#8211; This combination of erosion and deposition creates a winding channel, forming meanders.<br><br><img data-dominant-color=\"acb892\" data-has-transparency=\"false\" loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"202\" class=\"not-transparent wp-image-52962\" style=\"--dominant-color: #acb892; width: 300px;\" src=\"https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2025\/09\/Screenshot-2025-09-03-at-2.49.13-PM.png\" alt=\"\" srcset=\"https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2025\/09\/Screenshot-2025-09-03-at-2.49.13-PM.png 910w, https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2025\/09\/Screenshot-2025-09-03-at-2.49.13-PM-300x202.png 300w, https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2025\/09\/Screenshot-2025-09-03-at-2.49.13-PM-768x517.png 768w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p><strong>Source: <\/strong><a href=\"https:\/\/www.thehindu.com\/sci-tech\/energy-and-environment\/geographers-uncover-why-some-rivers-stay-single-while-others-split\/article69999220.ece#:~:text=%E2%80%9COur%20i\" rel=\"nofollow noopener\" target=\"_blank\"><strong>TH<\/strong><\/a><\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<h3><strong>Context<\/strong><\/h3>\n<li class=\"ms-5\">Researchers at the University of California, analysed 36 years of satellite data across 84 rivers worldwide to identify why some rivers maintain a single-thread channel, while others develop into braided or multi-thread systems.<\/li>\n<p><\/p>\n<h3><strong>Fluvial Processes and Channel Types<\/strong><\/h3>\n<li class=\"ms-5\">Rivers are broadly classified as single-thread or multi-thread (braided\/ anastomosing).\u00a0<\/li>\n<li class=\"ms-5\">In a single-thread river, lateral erosion of one bank is roughly matched by sediment deposition on the opposite bank.<\/li>\n<li class=\"ms-5\">This balance keeps the channel width constant and lets the river meander across its floodplain.<\/li>\n<li class=\"ms-5\">Multi-threaded rivers occur where bank erosion exceeds deposition.<\/li>\n<p><a href=\"https:\/\/www.nextias.com\/ca\/current-affairs\/02-09-2025\/why-some-rivers-stay-single\" class=\"btn btn-primary btn-sm float-end\">Read\u00a0More<\/a><\/p>\n","protected":false},"author":15,"featured_media":52891,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[21],"tags":[],"class_list":["post-52894","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-current-affairs"],"acf":[],"jetpack_featured_media_url":"https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2025\/09\/why-some-rivers-stay-single.png","_links":{"self":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/52894","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/comments?post=52894"}],"version-history":[{"count":11,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/52894\/revisions"}],"predecessor-version":[{"id":53336,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/52894\/revisions\/53336"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/media\/52891"}],"wp:attachment":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/media?parent=52894"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/categories?post=52894"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/tags?post=52894"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}