1.0Ace Geographyhttps://acegeography.comJakehttps://acegeography.com/author/jake/rich600338<blockquote class="wp-embedded-content" data-secret="WOvS6cph85"><a href="https://acegeography.com/drainage-basins/">Drainage basins</a></blockquote><iframe sandbox="allow-scripts" security="restricted" src="https://acegeography.com/drainage-basins/embed/#?secret=WOvS6cph85" width="600" height="338" title="“Drainage basins” — Ace Geography" data-secret="WOvS6cph85" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"></iframe><script> /*! This file is auto-generated */ !function(c,l){"use strict";var e=!1,o=!1;if(l.querySelector)if(c.addEventListener)e=!0;if(c.wp=c.wp||{},c.wp.receiveEmbedMessage);else if(c.wp.receiveEmbedMessage=function(e){var t=e.data;if(!t);else if(!(t.secret||t.message||t.value));else if(/[^a-zA-Z0-9]/.test(t.secret));else{for(var r,s,a,i=l.querySelectorAll('iframe[data-secret="'+t.secret+'"]'),n=l.querySelectorAll('blockquote[data-secret="'+t.secret+'"]'),o=0;o<n.length;o++)n[o].style.display="none";for(o=0;o<i.length;o++)if(r=i[o],e.source!==r.contentWindow);else{if(r.removeAttribute("style"),"height"===t.message){if(1e3<(s=parseInt(t.value,10)))s=1e3;else if(~~s<200)s=200;r.height=s}if("link"===t.message)if(s=l.createElement("a"),a=l.createElement("a"),s.href=r.getAttribute("src"),a.href=t.value,a.host===s.host)if(l.activeElement===r)c.top.location.href=t.value}}},e)c.addEventListener("message",c.wp.receiveEmbedMessage,!1),l.addEventListener("DOMContentLoaded",t,!1),c.addEventListener("load",t,!1);function t(){if(o);else{o=!0;for(var e,t,r,s=-1!==navigator.appVersion.indexOf("MSIE 10"),a=!!navigator.userAgent.match(/Trident.*rv:11\./),i=l.querySelectorAll("iframe.wp-embedded-content"),n=0;n<i.length;n++){if(!(r=(t=i[n]).getAttribute("data-secret")))r=Math.random().toString(36).substr(2,10),t.src+="#?secret="+r,t.setAttribute("data-secret",r);if(s||a)(e=t.cloneNode(!0)).removeAttribute("security"),t.parentNode.replaceChild(e,t);t.contentWindow.postMessage({message:"ready",secret:r},"*")}}}}(window,document); </script> Drainage basins and the source of a river The source of ariver The source of the river is where the river originates from. It is in the upper course of the long profile. A video on the source of the River Severn – http://www.bbc.co.uk/learningzone/clips/the-source-of-the-river-thames/12571.html A drainage basin A drainage basin is the area from which ... Read more