{"id":7687,"date":"2014-04-14T02:10:24","date_gmt":"2014-04-14T07:10:24","guid":{"rendered":"https:\/\/college.unc.edu\/?p=7687"},"modified":"2024-07-02T14:37:11","modified_gmt":"2024-07-02T14:37:11","slug":"freshwater","status":"publish","type":"post","link":"https:\/\/collegearchive.unc.edu\/?p=7687","title":{"rendered":"Finding fresh water"},"content":{"rendered":"
\"Tamlin<\/a>
Tamlin Pavelsky with Landsat images of the Alaska coast and the Tanana River in his office in Mitchell Hall at the University of North Carolina.<\/figcaption><\/figure>\n

How much fresh water is there around the world? The question seems like it would have an easy answer but UNC\u2019s Tamlin Pavelsky will tell you that\u2019s not the case.<\/p>\n

It turns out, if we need to know, for example, the total amount of water flowing through our rivers, the best estimate available could be off by about 40 percent. \u201cWe fundamentally don\u2019t really know,\u201d Pavelsky says.<\/p>\n

The answer, though, may come from miles above Earth\u2019s surface.<\/p>\n

As a global hydrologist in the geological sciences department<\/a> at UNC, Pavelsky is studying how to get more accurate estimates of Earth\u2019s freshwater supply. Because of his leadership in this field, Pavelsky has been awarded a prestigious Presidential Early Career Award for Scientists and Engineers. He will be at the White House this month to accept the award.<\/p>\n

More accurate estimates of our fresh water supply will help scientists and others in many ways. For instance, communities will be able to better prepare for floods. Scientists will gain a better understanding of the water cycle. The answers will also help scientists understand how global climate change is affecting Earth\u2019s water cycle.<\/p>\n

Using conventional, ground-based methods to measure the water in rivers, lakes, wetlands and other bodies of water is one way to estimate the freshwater supply, but that doesn\u2019t provide a full account for several reasons, Pavelsky says. First, in some parts of the world, such as China and India, the government doesn\u2019t release the data. In other parts, nobody is taking measurements. In parts of Africa, for example, the needed infrastructure simply doesn\u2019t exist.<\/p>\n

To get a more accurate picture of Earth\u2019s freshwater supplies, Pavelsky turns to satellite imagery. Measurements from satellites can show what is happening on a day-to-day basis as well as provide consistent measurements that date back more than 30 years to reveal how bodies of fresh water have changed.<\/p>\n

In December 2013, Pavelsky took on a large job with NASA, when he was appointed the lead U.S. scientist for hydrology for an upcoming NASA\/France joint satellite mission called the Surface Water Ocean Topography mission, or SWOT. Using radar technology, SWOT will provide the first global survey of Earth\u2019s water and measure how bodies of water change over time. The satellite will survey at least 90 percent of the Earth and study lakes, rivers, reservoirs and oceans about twice every 21 days. Pavelsky says the technology will provide scientists with the elevation of each freshwater body within about 10 centimeters of its actual height.<\/p>\n

\u201cWhat SWOT is going to do is it\u2019s going to really help us nail down what\u2019s going on with the water cycle now, and so we are going to have sort of this baseline that we can use to figure out how are things actually changing as time goes on,\u201d Pavelsky says.<\/p>\n

The mission launches in 2020, more than five years away, but Pavelsky says the timeline feels astonishingly short. He and others are studying technical aspects of how they will use the data. They also are working with engineers at the Jet Propulsion Laboratory at California Institute of Technology to ensure the correct design of the satellite.<\/p>\n

\u201cNo one has ever flown a satellite like this before. It\u2019s completely novel technology,\u201d Pavelsky says.<\/p>\n

Pavelsky\u2019s role with SWOT began in 2004 when he was a graduate student at the University of California-Los Angeles and participated in initial meetings about the mission and conducted some research related to it. His involvement increased after he became an assistant professor at UNC in 2009. In summer 2012, Pavelsky hosted a workshop at Carolina with scientists from around the world on how data collected from the mission will be used to measure flow through rivers. Over time, he took on more of a leadership role, culminating with his appointment this past December as the U.S. leader for the hydrology sciences part of the mission. Other scientists from the U.S. and France lead the mission\u2019s oceanography study.<\/p>\n

\u201cThis project overall is bigger than any single professor or researcher proposing it,\u201d Pavelsky says.<\/p>\n

Pavelsky says he grew up hiking and canoeing along remote rivers in Alaska, where he was born and primarily grew up. The experience \u201cgave me a deep love and appreciation for the movement of water across the landscape,\u201d he says.<\/p>\n

In graduate school, he focused on understanding the Arctic river systems.<\/p>\n

\u201cI\u2019ve always loved maps and other spatial representations of the landscape, so it was natural for me to study the earth from above using satellite images. Combining these two, I ended up focusing on using satellite images to understand Arctic rivers.\u201d<\/p>\n

Now, he\u2019s using that knowledge to study all of the Earth\u2019s rivers.<\/p>\n

[By Natalie Vizuete]<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

How much fresh water is there around the world? The question seems like it would have an easy answer but UNC\u2019s Tamlin Pavelsky will tell you that\u2019s not the case.<\/p>\n","protected":false},"author":4,"featured_media":7925,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[16,17,21],"tags":[24,2209,77,2210],"class_list":["post-7687","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-global-programs","category-natural-sciences-mathematics","category-news","tag-carolina","tag-fresh-water","tag-mathematics","tag-nautral-sciences"],"_links":{"self":[{"href":"https:\/\/collegearchive.unc.edu\/index.php?rest_route=\/wp\/v2\/posts\/7687","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/collegearchive.unc.edu\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/collegearchive.unc.edu\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/collegearchive.unc.edu\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/collegearchive.unc.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7687"}],"version-history":[{"count":2,"href":"https:\/\/collegearchive.unc.edu\/index.php?rest_route=\/wp\/v2\/posts\/7687\/revisions"}],"predecessor-version":[{"id":46585,"href":"https:\/\/collegearchive.unc.edu\/index.php?rest_route=\/wp\/v2\/posts\/7687\/revisions\/46585"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/collegearchive.unc.edu\/index.php?rest_route=\/wp\/v2\/media\/7925"}],"wp:attachment":[{"href":"https:\/\/collegearchive.unc.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7687"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/collegearchive.unc.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7687"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/collegearchive.unc.edu\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7687"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}