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Posts tagged Wetlands

Climate Change Affecting Mississippi Delta Region, USA – January 25th, 2013

29.9N 90W

January 25th, 2013 Category: Image of the day, Wetlands

USA – January 17th, 2013

This image shows the Mississippi Delta Region, which represents one of the most vulnerable regions of the Gulf Coast. The combined effects of engineered and altered landscapes, natural subsidence, and climate change will have tremendous consequences for human well-being, natural resources, and biodiversity.

Over the past century, the nearly 1.3 million square mile watershed of the Mississippi River has experienced major environmental changes, including conversion of more than 80 percent of forested wetlands to agriculture and urban areas, channelization, dam construction, and river levees. The construction of massive structures that keep the river from switching channels has restricted sediment and freshwater supply to the flood plain.

These changes have been especially damaging to the region’s wetlands. The coastal wetlands associated with the Mississippi River delta make up nearly 40 percent of the total coastal salt marsh in the lower 48 states of the U.S. These wetlands are disappearing at an average rate of 25 square miles per year, about 50 acres each day. Already, more than one thousand square miles of freshwater wetlands in Louisiana have been lost or converted to other habitats. Only about 20 percent of the original bottomland hardwood forests and swamps in the lower Mississippi River valley remain today.

Some of these wetland losses are due to delta subsidence (sinking), which results in relative sea-level rise. Although subsidence is a natural process, human interference with river and sediment flow and withdrawal of groundwater have exacerbated it (click here for more information).

Game Reserves Along Nikonga River, Tanzania

3.8S 31.8E

August 23rd, 2010 Category: Rivers

Uganda and Tanzania - August 3rd, 2010

Uganda and Tanzania - August 3rd, 2010

This APM image shows the Moyowosi (left) and the Kigosi (right) Game Reserves in northwestern Tanzania. The two are separated by the Nikonga River, visible just left of the image center. Both reserves are located within the Malagalasi-Moyowosi Wetland and are excellent examples of an East African floodplain wetland ecosystem.

The Moyowosi Game Reserve is categorized as a RAMSAR Wetland of International Importance. The vegetation is mainly Miombo woodland, adjacent to plains and wetlands that are covered with swamp. It provides an important dry season refuge and feeding area for migratory animals including many water birds and large mammal species.

The Kigosi Game Reserve, on the other hand, is dominated with grassy swamps to the south and open Miombo woodland to the north, allowing the Moyowosi, Nikonga, Kigosi and Gombe River to flow through the floodplain.

Dutch Coastal Bodies of Water: Markermeer, IJsselmeer and Wadden Sea – May 31st, 2010

May 31st, 2010 Category: Image of the day, Lakes

Netherlands - April 18th, 2010

Netherlands - April 18th, 2010

Several bodies of water are visible near the coast of the Netherlands: the Markermeer (bright green), the IJsselmeer (dark blue) and the Wadden Sea (green, closest to the open ocean).

The Markermeer is a 700 km² lake in the central Netherlands in between North Holland, Flevoland and its larger sibling, the IJsselmeer. A shallow lake at some 3 to 5 m in depth, it is named after the small former island, now peninsula, of Marken that lies within it.

IJsselmeer (sometimes translated as Lake IJssel, alternative international spelling: Lake Yssel) is a shallow lake of 1100 km² in the central Netherlands bordering the provinces of Flevoland, North Holland and Friesland, with an average depth of 5 to 6 m. It is named after the IJssel river that drains into it via a smaller lake, the Ketelmeer. The IJsselmeer is the largest lake in Western Europe.

The Wadden Sea (Dutch: Waddenzee) is an intertidal zone in the southeastern part of the North Sea. It lies between the coast of northwestern continental Europe and the range of Frisian Islands, forming a shallow body of water with tidal flats and wetlands.

Wetlands of the Venetian Lagoon and Po Delta, Italy

45.4N 12.3E

May 30th, 2010 Category: Lakes, Rivers, Sediments

Italy - April 28th, 2010

Italy - April 28th, 2010

The Venetian Lagoon (center left) appears green in this image of northern Italy. The lagoon is the enclosed bay of the Adriatic Sea in which the city of Venice is situated. It is the largest wetland in the Mediterranean Basin.

The lagoon stretches from the River Sile in the north to the Brenta in the south, with a surface area of around 550 km². It is around 8% land, including Venice itself and many smaller islands. About 11% is permanently covered by open water, or canal, as the network of dredged channels are called, while around 80% consists of mud flats, tidal shallows and salt marshes.

Another important area of wetlands is visible to the south: the delta of the River Po. Much of the delta is a protected park, with 53,653 ha (132,580 acres) containing wetlands, forest, dunes and salt pans. It has a high biodiversity, with 1000-1100 plant species and 374 vertebrate species, of which 300 are birds.

Troodos Mountains and Limassol Salt Lake, Cyprus

34.6N 32.9E

May 9th, 2010 Category: Lakes, Mountains

Cyprus - April 28th, 2010

Cyprus - April 28th, 2010

The physical relief of the island of Cyprus is dominated by two mountain ranges, the Troodos Mountains and the smaller Kyrenia Range, and the central plain they encompass, the Mesaoria. The Troodos Mountains cover most of the southern and western portions of the island and account for roughly half its area, appearing dark green here.

Also of note, although better visible in the full image, is Limassol salt lake (also known as Akrotiri salt lake), the largest inland body of water in Cyprus. It is located on a peninsula on the southern coast of the island and appears bright green in color.

The lake lies due south-east of the sprawling city of Limassol and measures 10.65 km². Its lowest point is 2.7m below sea level and at its deepest point the water depth measures 1m. Geologists hypothesize the lake was formed over the gradual joining of an offshore islet off the southern coast of Cyprus.

The lake itself is considered to be one of the eastern Mediterranean’s most important wetlands. The fact that the water level over 50% of the lake is less than 30 cm deep attracts thousands of wading birds to use it as a stopover during the migration seasons. Birdlife International estimates that between 2,000 and 20,000 Greater Flamingos (Phoenicopterus roseus) spend the winter months on the lake.