Posted on June 12th, 2012

Our Changing Landscape – The Dead Sea

In this new monthly feature, we span the globe to examine Our Changing Landscape with time series of medium resolution RapidEye satellite imagery. The RapidEye archive dates back to late 2008 and already contains more than 3 billion square kilometers of data. This month, we travel to the Middle East and explore changes in the water depth of the Dead Sea.

The RapidEye Constellation

RapidEye is a constellation of five 5-meter medium resolution satellites each offering five spectral bands of information. The RapidEye constellation offers a daily revisit time to every location on the planet with a huge footprint that is 77-km wide. The data is priced competitively with a base price of $1.28 per square kilometer for all five spectral bands – academics receive a discount on this price. RapidEye adds a fifth band, the red edge, to the ‘traditional’ multispectral set of blue, green, red and near-infrared (NIR). The additional spectral data available in the red edge band allows users to extract more useful land ‘information’ than can be from traditional 4-band imagery sources. When RapidEye imagery is ordered as a Level 3A Orthorectified product, images from multiple dates are extremely well registered, making it the ideal data source for Our Changing Landscape.

The Dead Sea

Surrounded by Israel to the west and Jordan to the east, the Dead Sea is a land locked body of water with no natural outflow to the ocean. At ~400 feet below sea level, the Dead Sea is the lowest land on Earth. Without a natural outflow to the ocean, salt concentrates in the Dead Sea as fresh water flows into the basin and evaporates. In fact, the Dead Sea’s salinity concentration is over 33% compared to just 3% in the Mediterranean Sea.

In the long history of the Dead Sea, it is not unusual for it to dry up almost completely, as it apparently did ~100,000 years ago. However, recent population and economic growth in the Middle East – and subsequent use of the fresh waters in the Jordan River – have put significant strain on this delicate ecosystem. The Jordan River is the most important source of fresh water feeding the Dead Sea, once emptying some 1.3 billion cubic meters of water per year into the sea in the 1930s. Today, the inflow from the Jordan River is just 20 to 30 million cubic meters. With this dramatic decrease in total inflow, the water levels in the Dead Sea are falling by more than a meter per year. The animation below comprised of 5-meter natural color RapidEye images from 2010, 2011 and 2012 provides visual evidence of a rapidly changing Dead Sea.


RapidEye_Anime_DeadSea (1)

Click on the image above to see an animation of changes in the Dead Sea’s water depth. This three layer imagery stack contains 5-meter natural color RapidEye images collected on 1/27/2010, 7/25/2011 and 3/5/2012. Focus on the shoreline in the animation to see the retreat of the Dead Sea during this ~2 year span. We took ten spot measurements from the top of the water in 2010 to its level in 2012 and found alarming changes: the average change was 90.3 meters with a range of retreat from 33 to 183 meters in a straight line distance. (Images Courtesy: RapidEye)

 

If you would like to find out more about using RapidEye for your academic studies, engineering projects or any landscape analysis, let us know at sales@apollomapping.com or (303) 993-3863.

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