Featured Research

from universities, journals, and other organizations

Landslides: How rainfall dried up Panama's drinking water

Date:
May 18, 2011
Source:
Smithsonian Tropical Research Institute
Summary:
An aerial survey of landslides has helps scientists evaluate the effect of a prolonged tropical storm on the water supply in the Panama Canal watershed.

Heavy rains cause landslides on the steep slopes of the Panama Canal watershed, releasing large quantities of sediment into rivers and streams.
Credit: Robert Stallard

An aerial survey of landslides has helps scientists evaluate the effect of a prolonged tropical storm on the water supply in the Panama Canal watershed. To understand the long-term effects of a prolonged tropical storm in the Panama Canal watershed, Robert Stallard, staff scientist at the Smithsonian Tropical Research Institute and research hydrologist at the U.S. Geological Survey, and Armando Ubeda, the LightHawk Mesoamerica program manager, organized four flights over the watershed to create a digital map of landslide scars.

Related Articles


Two feet of heavy rain inundated the Panama Canal watershed between Dec. 7 and 10, 2010. Landslides tore down steep slopes, choking rivers with sediment and overwhelming Panama City's water-treatment plant. Flooding closed the Panama Canal for the first time since 1935. Despite the deluge, the influx of sediments in the water forced authorities to shut down the plant, leaving a million residents of central Panama without clean drinking water for nearly a month.

LightHawk, a conservation organization based in the U.S., donates flights for research and conservation efforts. Retired United Airlines captain David Cole flew the Cessna 206 aircraft, and the four flights yielded images of 191 square miles (495 square kilometers) of watershed. Stallard observed numerous new landslide scars left behind by the December storm, supporting his prediction that landslides supplied much of the suspended sediment that disrupted Panama's water supply.

The new watershed erosion map will allow Stallard and collaborators from the Panama Canal Authority to calculate the landslide risk of future storms and direct strategies to minimize the effect on Panama's water supply.

Tropical hydrologists agree that river-borne sediment originates from surface erosion or from deep erosion from landslides. In 1985, Stallard predicted that "deep erosion, not shallow surface erosion, is the primary process controlling the chemistry and sediment levels in many tropical rivers that pass through mountainous areas." Few studies have been conducted to test this prediction.

Deforestation of steep slopes is the primary factor determining the number of landslides. Six decades of aerial photographs analyzed by USGS researchers in similar landscapes in Puerto Rico showed that landslide frequency doubles outside protected nature preserves, and that roads and infrastructure make landslides eight times more likely. Although landslides happen in natural forests, the objective is to limit their impact through appropriate land-use practices.

"With development, landslide intensity increases dramatically," said Stallard. "In its history, the Panama Canal watershed has experienced huge floods. It's still hard to say whether future floods will be accompanied by disastrous landslides like those produced by Hurricane Mitch in Central America." In 1998, Hurricane Mitch swept across Honduras, Guatemala, Nicaragua and El Salvador causing more than 10,000 deaths and incalculable economic damage. Panama's proximity to the equator puts the country outside the usual hurricane zone, but prolonged tropical storms may occur.

Erosion control is possible. Partnering with the Panama Canal Authority and Panama's Environmental Authority, the Smithsonian is conducting a 700 hectare experiment in the canal watershed funded by the HSBC Climate Partnership to compare the effects of land-use choices, such as cattle ranching or reforestation with native tree species on water supply, carbon storage and biodiversity. Stallard hopes that this research will provide new information about which land uses provide a steady supply of clean water for the Canal.

With the first rains in May, the eight-month wet season begins anew in central Panama. Drinking water flows freely, the rivers are clear and the Panama Canal is open for business. But bare slopes of past landslides continue to create secondary erosion, which will dislodge sediments from the steep, rainy and rugged Panama Canal watershed in 2011. The long-term effects of the 2010 storm may continue as renewed interruptions in the water supply in 2011.


Story Source:

The above story is based on materials provided by Smithsonian Tropical Research Institute. Note: Materials may be edited for content and length.


Cite This Page:

Smithsonian Tropical Research Institute. "Landslides: How rainfall dried up Panama's drinking water." ScienceDaily. ScienceDaily, 18 May 2011. <www.sciencedaily.com/releases/2011/05/110517110321.htm>.
Smithsonian Tropical Research Institute. (2011, May 18). Landslides: How rainfall dried up Panama's drinking water. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2011/05/110517110321.htm
Smithsonian Tropical Research Institute. "Landslides: How rainfall dried up Panama's drinking water." ScienceDaily. www.sciencedaily.com/releases/2011/05/110517110321.htm (accessed October 25, 2014).

Share This



More Earth & Climate News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU Gets Climate Deal, UK PM Gets Knock

EU Gets Climate Deal, UK PM Gets Knock

Reuters - Business Video Online (Oct. 24, 2014) EU leaders achieve a show of unity by striking a compromise deal on carbon emissions. But David Cameron's bid to push back EU budget contributions gets a slap in the face as the European Commission demands an extra 2bn euros. David Pollard reports. Video provided by Reuters
Powered by NewsLook.com
Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Raw: Tornado Rips Roofs in Washington State

Raw: Tornado Rips Roofs in Washington State

AP (Oct. 24, 2014) A rare tornado ripped roofs off buildings, uprooted trees and shattered windows Thursday afternoon in the southwest Washington city of Longview, but there were no reports of injuries. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Fast-Moving Lava Headed For Town On Hawaii's Big Island

Fast-Moving Lava Headed For Town On Hawaii's Big Island

Newsy (Oct. 24, 2014) Lava from the Kilauea volcano on Hawaii's Big Island has accelerated as it travels toward a town called Pahoa. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins