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Archive for Rivers

Vegetation Index by Rivers of Western Africa

12.4N 16.4W

January 27th, 2012 Category: Rivers, Vegetation Index

Guinea Bissau - January 6th, 2012

This FAPAR image shows the vegetation index of the Gambia, Senegal and Guinea Bissau, in Western Africa. The index in Gambia and northern Senegal is quite low (yellow), with areas of good (green) photosynthetic activity visible only near the banks of the Gambia River.

To the south, the vegetation index is generally good, particularly near the coast and the Geba River, on on the offshore islands. Here, the distribution of activity appears to be the opposite of the pattern to the north: lower activity is visible by the banks of the rivers.

Vegetation Index Near Lakes Ghana and Kainji, Ghana and Nigeria

7.1N 0.1E

October 25th, 2011 Category: Lakes, Rivers, Vegetation Index

Ghana, Togo, Benin, Nigeria - October 24th, 2011

This FAPAR image shows the vegetation index of Ghana, Togo, Benin and Nigeria (left to right along the coast). Visible to the left is Lake Volta, in Ghana, and visible at the upper right is Lake Kainji, on the Niger River, in Nigeria.

The vegetation index is generally good (green) throughout the image. However, there are some areas of high photosynthetic activity (rusty red), particuarly in the vicinity of Lake Volta.

Vegetation Index Near Mississippi River, USA

33.5N 92.3W

April 2nd, 2011 Category: Rivers, Vegetation Index

USA - April 2nd, 2011

This FAPAR image shows an area of terrain in the United States near the Mississippi River (running parallel to the right edge) and northwest of the Gulf of Mexico (bottom right).

Photosynthetic activity is generally good (green) near the gulf, and becomes lower (yellow) as one moves northward. A few scattered areas of high activity (rusty red) can be observed in the full image near the left edge.


Drought Affects Brazilian Amazon

3.2S 60.1W

October 30th, 2010 Category: Climate Change, Rivers, Vegetation Index

Brazil - September 14th, 2010

The full version of this FAPAR image stretches from northeastern Venezuela, Guyana, Suriname and French Guiana (left to right along the coast), across the Brazilian Amazon Rainforest, to the southern border of Brazil.

The areas showing the highest vegetation index (rusty red) are found in northeastern Venezuela. The other countries along the coast show a mostly good index (green). At the bottom of the full image, multiple large deforested areas in Brazil show a low index (yellow).

Interestingly, the Amazon Rainforest itself generally shows only a good index. This may be because it is being afflicted by an unusual severe drought. Some rivers are at their lowest level in decades, including the Amazon River at Manáus (visible near the center of the full image), which has fallen to its lowest level since 1963.

Scientists say the region is facing its worst drought since that year. The Peruvian Amazon, 2,000km (1,240 miles) upstream has also been affected. In Amazonas state 27 municipalities have declared a state of emergency because of the dry spell. Several tributaries of the Amazon have almost completely dried up, paralysing river transport and the fishing industry.

The Brazilian government has announced $13.5m (£8.6m) in emergency aid for Amazon regions hit by the worst drought in decades. The money will fund water pumping and purification, as well as food deliveries to towns cut off by the drop in river levels.

Environmental groups say severe droughts are likely to become more frequent in the Amazon as a result of global warming, putting further strain on the rainforest.

Vegetation Index of Orinoco River Basin and Surroundings, Venezuela and Colombia

6.2N 68.6W

October 29th, 2010 Category: Rivers, Vegetation Index

Venezuela and Colombia - October 8th, 2010

This FAPAR image shows the vegetation index of Venezuela and parts of Colombia. Interestingly, the index is lowest (yellow in color) in the basin of the Orinoco River, which cuts diagonally across the image from southwest to northeast.

The index is highest (rusty red) to the west of the river basin, while that of the terrain to the east of the basin shows a generally good (green) index of photosynthetic activity.