Category Archives: Hydrology

Food insecurity follows floods in Sri Lanka

By Amantha Perera

Food shortages brought on by extreme weather events have resulted in almost a quarter of Sri Lanka’s 21 million people becoming malnourished, says a World Food Programme (WFP) document.

“The increased frequency of natural disasters such as drought and flash floods further compounds food and nutrition insecurity,” says the document, the latest WFP country brief for Sri Lanka, released in June.

As per WFP’s most recent Cost of Diet Analysis, almost 6.8 million (33 per cent) Sri Lankans cannot afford the minimum cost of a nutritious diet and a large portion of this vulnerable population lives in poverty and is frequently subjected to extreme weather events.

monsoon_rains_Sri_Lanka
Loss of land and livelihood from flooding caused to erratic monsoon rains. Image from Flickr.

In May heavy rains, brought on by Cyclone Roanu, affected 340,000 persons in 22 of the island’s 25 districts. “These people have very limited coping mechanisms, and these kinds of disasters can drive them deeper into poverty,” says minister for disaster management Anura Priyadarshana Yapa.

After the landslides and rains the government decided to shift out those living in high-risk areas but, according to public officials, they were faced with the problems of locating safe land and making income from agriculture.

“Most of those living on these high-risk areas rely on agriculture and we need to see how to secure their livelihoods,” head of the disaster management centre, Kegalle district, tells SciDev.Net.

The UN estimates that every year around 700,000 Sri Lankans are impacted by extreme weather, some repeatedly. “A sizeable segment of the flood affected population are squatters living in vulnerable areas prone to frequent flooding,” the UN Office for the Coordination of Humanitarian Affairs said following estimates made soon after the May floods and landslides.

“We need to develop long-term solutions, not stop-gap answers,” says Yapa, agreeing that there were serious problems arising from erratic weather patterns in Sri Lanka in recent years.

This article was originally published on SciDev.Net. Read the original article.

 

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Earth’s Changing Surface water

Scientists have used satellite observations to study how the distribution of land and water on the Earth’s surface has changed over the last 30 years.

They found that the Earth’s surface has gained 115,000 sq km of water of extra water bodies and 173,000 sq km of water has now become land. The study is published in Nature Climate Change.

The interactive Aqua Monitor was developed by the Deltares Research Institute in the Netherlands. It is the first global-scale tool that shows, with a 30 metre resolution, where water has been transformed into land and vice-versa.

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New lakes – seen in blue – are appearing on the Tibetan Plateau. Image: Deltares Aqua Monitor

The largest increase in water has been on the Tibetan Plateau, where increased water from melting glaciers are creating huge new lakes.

A rise in the number of dams built over the last 30 years has also increased the number of inland water bodies. Using the satellite data, the team were able to identify previously unreported constructions in Myanmar and North Korea.

The Aral Sea, which lies between Kazakhstan and Uzbekistan, has seen the the greatest conversion of water into land. Formerly one of the four largest lakes in the world, the Aral Sea has been steadily shrinking since the 1960s after the rivers that fed it were diverted by Soviet irrigation projects.

Aral_Sea
The Aral Sea has almost completely dried out. Green here shows the area of water that has converted to land. Image: Deltares Aqua Monitor

There have also been striking changes along our coastlines. The largest coastal water to land change is the construction of Palm Island and adjacent islands along the coast of Dubai. Many countries have shaped and extended their coastlines by land reclamation, including almost the entire coastline of eastern China from the Yellow Sea all the way down to Hong Kong.

Big data at everyone’s fingertips
Universally-available analytics for big satellite data may have major implications for monitoring capacity. At the very local scale, members of the general public can now make assessments without expert assistance if their houses are threatened by coastal erosion. At the regional scale, countries can monitor their water body changes and assess flooding impacts and strategy for disaster risk reduction.

Jaap Kwadijk, the Deltares scientific director: “This has never been done before. So it is difficult to imagine all the new applications that will be made using this tool. But the tool can be used by everybody and so I am sure multiple applications will emerge in the next few years”.

Original Paper: http://www.nature.com/nclimate/journal/v6/n9/full/nclimate3111.html