{"id":127249,"date":"2020-09-21T08:00:24","date_gmt":"2020-09-21T18:00:24","guid":{"rendered":"https:\/\/www.hawaii.edu\/news\/?p=127249"},"modified":"2020-10-19T14:42:41","modified_gmt":"2020-10-20T00:42:41","slug":"oahu-beaches-lost-mid-century","status":"publish","type":"post","link":"https:\/\/www.hawaii.edu\/news\/2020\/09\/21\/oahu-beaches-lost-mid-century\/","title":{"rendered":"40% of O\u02bbahu beaches could be lost by mid-century"},"content":{"rendered":"<span class=\"span-reading-time rt-reading-time\" style=\"display: block;\"><span class=\"rt-label rt-prefix\">Reading time: <\/span> <span class=\"rt-time\"> 2<\/span> <span class=\"rt-label rt-postfix\">minutes<\/span><\/span><div class=\"responsive-video-wrap-post\"><figure class=\"wp-block-embed wp-block-embed-youtube is-type-video is-provider-youtube epyt-figure\"><div class=\"wp-block-embed__wrapper\"><div class=\"epyt-video-wrapper\"><iframe  id=\"_ytid_96151\"  width=\"676\" height=\"676\"  data-origwidth=\"676\" data-origheight=\"676\" src=\"https:\/\/www.youtube.com\/embed\/eijWzH2806g?enablejsapi=1&origin=https:\/\/www.hawaii.edu&rel=0&autoplay=0&cc_load_policy=0&cc_lang_pref=&iv_load_policy=1&loop=0&fs=1&playsinline=0&autohide=2&theme=dark&color=red&controls=1&disablekb=0&\" class=\"__youtube_prefs__  no-lazyload\" title=\"40% of O\u02bbahu beaches could be lost by mid-century\"  allow=\"fullscreen; accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen data-no-lazy=\"1\" data-skipgform_ajax_framebjll=\"\"><\/iframe><\/div><\/div><\/figure><\/div>\n<p>The reactive and piecemeal approach historically used to manage beaches in <span aria-label=\"Hawaii\">Hawai&#699;i<\/span> has failed to protect them, according to a <a href=\"https:\/\/www.nature.com\/articles\/s41598-020-70577-y\">new study<\/a> by researchers in the <a href=\"http:\/\/www.soest.hawaii.edu\/coasts\/\">Coastal Geology Group<\/a> at the University of <span aria-label=\"Hawaii\">Hawai&#699;i<\/span> at M&#257;noa <a href=\"https:\/\/www.soest.hawaii.edu\/soestwp\/\">School of Ocean and Earth Science and Technology<\/a> (<abbr>SOEST<\/abbr>). The study also found that if policies are not changed, as much as 40 percent of all beaches on <span aria-label=\"Oahu\">O&#699;ahu<\/span> could be lost before mid-century.<\/p>\n<p>In an era of rising sea-level, beaches need to migrate landward, otherwise they drown. Beach migration, also known as shoreline retreat, causes coastal erosion of private and public beachfront property. Shoreline hardening, the construction of seawalls or revetments, interrupts natural beach migration&#8212;causing waves to erode the sand, accelerating coastal erosion on neighboring properties, and dooming a beach to drown in place as the ocean continues to rise.<\/p>\n<div style=\"float:right;clear:right;margin:0 0 0 15px;\"><figure id=\"attachment_127255\" aria-describedby=\"caption-attachment-127255\" style=\"width: 300px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2020\/09\/manoa-soest-oahu-beaches-3-300x169.jpg\" alt=\"houses on the beach with erosion\" width=\"300\" height=\"169\" class=\"size-medium wp-image-127255\" srcset=\"https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2020\/09\/manoa-soest-oahu-beaches-3-300x169.jpg 300w, https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2020\/09\/manoa-soest-oahu-beaches-3-130x73.jpg 130w, https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2020\/09\/manoa-soest-oahu-beaches-3.jpg 676w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption id=\"caption-attachment-127255\" class=\"wp-caption-text\">Erosion at Rocky Point, <span aria-label=\"Oahu\">O&#699;ahu<\/span> is visible in this drone image. (Photo credit: Shellie Habel)<\/figcaption><\/figure><\/div>\n<div style=\"float:right;clear:right;margin:0 0 0 15px;\"><figure id=\"attachment_127257\" aria-describedby=\"caption-attachment-127257\" style=\"width: 300px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2020\/09\/manoa-soest-oahu-beaches-300x169.jpg\" alt=\"beach on oahu with seawall\" width=\"300\" height=\"169\" class=\"size-medium wp-image-127257\" srcset=\"https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2020\/09\/manoa-soest-oahu-beaches-300x169.jpg 300w, https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2020\/09\/manoa-soest-oahu-beaches-130x73.jpg 130w, https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2020\/09\/manoa-soest-oahu-beaches.jpg 676w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption id=\"caption-attachment-127257\" class=\"wp-caption-text\">Shoreline hardening protects a road on <span aria-label=\"Oahu\">O&#699;ahu<\/span> and has led to beach loss. (Photo credit: Kammie Tavares)<\/figcaption><\/figure><\/div>\n<div style=\"float:right;clear:right;margin:0 0 0 15px;\"><figure id=\"attachment_127256\" aria-describedby=\"caption-attachment-127256\" style=\"width: 300px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2020\/09\/manoa-soest-oahu-beaches-2-300x169.jpg\" alt=\"beach on oahu\" width=\"300\" height=\"169\" class=\"size-medium wp-image-127256\" srcset=\"https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2020\/09\/manoa-soest-oahu-beaches-2-300x169.jpg 300w, https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2020\/09\/manoa-soest-oahu-beaches-2-130x73.jpg 130w, https:\/\/www.hawaii.edu\/news\/wp-content\/uploads\/2020\/09\/manoa-soest-oahu-beaches-2.jpg 676w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption id=\"caption-attachment-127256\" class=\"wp-caption-text\">Residential areas experience beach loss due to erosion and shoreline hardening. (Photo credit: Kammie Tavares)<\/figcaption><\/figure><\/div>\n<p>The team of scientists, led by graduate researcher <strong>Kammie Tavares<\/strong> in <abbr>SOEST<\/abbr>\u2019s <a href=\"http:\/\/www.soest.hawaii.edu\/gg\/\">Department of Earth Sciences<\/a>, assessed the shoreline around <span aria-label=\"Oahu\">O&#699;ahu<\/span> that would be most vulnerable to erosion under three scenarios of sea-level rise&#8212;all estimated to occur around mid-century.<\/p>\n<h2>Shoreline hardening and beach loss<\/h2>\n<p>They identified the location and severity of risk of shoreline hardening and beach loss, and a potential timeline for the increase in erosion hazards. The most threatened properties fall into an &ldquo;administrative erosion hazard zone,&rdquo; an area likely to experience erosion hazards and qualify for the emergency permitting process to harden the shoreline.<\/p>\n<p>&ldquo;By assessing computer models of the beach migration caused by 9.8 inches (0.25 meters) of sea-level rise, an amount with a high probability of occurring before mid-century, we found that emergency permit applications for shoreline hardening to protect beachfront property will substantially increase,&rdquo; said Tavares.<\/p>\n<p>According to co-author <strong>Tiffany Anderson<\/strong>, assistant researcher in the Department of Earth Sciences, &ldquo;We determined that almost 30 percent of all present-day sandy shoreline on <span aria-label=\"Oahu\">O&#699;ahu<\/span> is already hardened, with another 3.5 percent found to be so threatened that those areas qualify for an emergency permit today. Our modeling indicates that, as sea-level rises about 10 inches (0.25 meters) by mid-century, an additional nearly eight percent of sandy shoreline will be at risk of hardening&#8212;meaning at that point, nearly 40 percent of <span aria-label=\"Oahu\u2019s\">O&#699;ahu\u2019s<\/span> sandy beaches could be lost in favor of hardened shorelines.&rdquo;<\/p>\n<p>&ldquo;In another <a href=\"https:\/\/link.springer.com\/article\/10.1007\/s10584-018-2327-7\">study published in 2018<\/a>, we showed that accelerated erosion on neighboring properties, called flanking, usually leads to additional shoreline hardening, and condemns entire beaches,&rdquo; said co-author <strong>Chip Fletcher<\/strong>, associate dean and professor in <abbr>SOEST<\/abbr>. &ldquo;It is clear that management decisions made today, and during the careers of most of today\u2019s natural resource managers, will be critical in determining if future generations will inherit a healthy shoreline, or one that has been ruined by seawalls, and other types of shoreline hardening.&rdquo;<\/p>\n<p>Continue reading on <a href=\"https:\/\/www.soest.hawaii.edu\/soestwp\/announce\/news\/40-of-o%ca%bbahu-beaches-could-be-lost-by-mid-century\/\"><abbr>SOEST<\/abbr>&#8216;s website<\/a>.<\/p>\n<p><em>&#8211;By Marcie Grabowski<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Researchers assessed the shoreline around <span aria-label=\"Oahu\">O&#699;ahu<\/span> most vulnerable to erosion under three scenarios of sea-level rise&#8212;all estimated to occur before, and shortly after mid-century.<\/p>\n","protected":false},"author":16,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[30,12],"tags":[93,801,1187,1363,158,92,942,9,56],"class_list":["post-127249","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research","category-video","tag-climate-change","tag-coastal-erosion","tag-earth-science","tag-manoa-research","tag-publication","tag-school-of-ocean-and-earth-science-and-technology","tag-sea-level","tag-uh-manoa","tag-video-2","entry","has-media"],"aioseo_notices":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/posts\/127249","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/comments?post=127249"}],"version-history":[{"count":13,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/posts\/127249\/revisions"}],"predecessor-version":[{"id":156262,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/posts\/127249\/revisions\/156262"}],"wp:attachment":[{"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/media?parent=127249"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/categories?post=127249"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hawaii.edu\/news\/wp-json\/wp\/v2\/tags?post=127249"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}