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Archive for Lakes

Climate Change’s Impacts on Lake Poopó, Bolivia: Reduced Area and Biodiversity – July 1st, 2013

18.7S 67W

July 1st, 2013 Category: Climate Change, Image of the day, Lakes, Salt Flats VIIRSSuomi-NPP

Bolivia – June 28th, 2013

Visible high on the Bolivian altiplano are the green waters of Lake Poopó and the bright white surface of the Salar de Uyuni. Lake Poopó’s area has decreased by 50% in the last 25 years, with serious consequences for the populations of resident and migratory waterbirds.

The lake is located at approximately 3700 m above sea level, covering an approximate area of 967,000 ha, making it the second biggest lake in Bolivia, after Lake Titicaca (visible in the upper part of the full image), which is shared with Peru. However, in only 25 years its area has decreased by about 17,400 ha, representing almost 50% of its total area.

The decrease in the wetland’s area of open water has been attributed principally to climate change, which, in conjunction with current hydrological conditions (high rates of evaporation, low rainfall, and low flow rates of the rivers flowing into the lake), mean that water levels in the lake are not rising. This has had serious impacts on the biodiversity which depends on the wetland, given that the salinity has increased, thus decreasing survival rates of some species, with subsequent consequences in the local economy.

The change in size of the wetland has represented a considerable loss of available habitat for migratory bird species, for which the lake represents an important habitat, especially during the dry season (May to September), coinciding with the southern winter. However, drastic decreases in the populations of these species have been detected since 2007. Preliminary results suggest that the reason for this decline is the loss of available habitat as a result of the reduced area of Lake Poopó, and the accumulation of solid waste around the shores of the lake (click here for more information).


Lake Balkhash and Climate Change’s Effects on Lakes in Central Asia – June 11th, 2013

42.8N 81.3E

June 11th, 2013 Category: Climate Change, Deserts, Image of the day, Lakes VIIRSSuomi-NPP

Kazakhstan and China – June 10th, 2013

Lakes in arid regions of Central Asia, such as Lake Balkhash, in Kazakhstan (upper left), northwest of China’s Taklamakan Desert (below), act as essential components of regional water cycles, providing sparse but valuable water resource for the fragile ecological environments and human lives.

Lakes in Central Asia are sensitive to climate change and human activities, and great changes have been found since 1960s. Mapping and monitoring these inland lakes can improve our understanding of mechanism of lake dynamics and climatic impacts. Satellite altimetry provides an efficient tool of continuously measuring lake levels in these poorly surveyed remote areas.

Scientists have shown that alpine lakes are increasing greatly in lake levels during 2003-2009 due to climate change, while open lakes with dams and plain endorheic lakes decrease dramatically in water levels due to human activities, which reveals the overexploitation of water resource in Central Asia (click here for more information).

Desertification, Water Loss and Temperature Changes in the Aral Sea – June 9th, 2013

45.2N 59.8E

June 9th, 2013 Category: Climate Change, Image of the day, Lakes MODISAqua

Aral Sea – June 9th, 2013

The primary effect of the Aral Sea desiccation has been the significant loss of water in the sea. The water level has dropped approximately 23 meters since the onset of its primary sources of water being diverted. Although the water level has fluctuated up to a few meters in the past due to natural variability in the water flow from the rivers, by 1970, the water loss exceeded the limit of natural water level variation that has occurred in the past.

The desiccation of the Aral Sea has been accompanied by the change in the Sea Surface Temperature. We see that the summer SSTs have been increasing, while winter SSTs have been decreasing. This is expected because as the sea loses volume, its heat capacity is reduced, therefore it can warm up and cool off faster than before. The day to night variations in SSTs, which are responsible for the sea breezes, have also increased.

In a sense, Aral sea has started to exhibit a monsoon climate, which is characterized by seasonal climate change due to warming and cooling of the sea. The desiccation period was also characterized by less ice covering of the sea. This can be explained by the fact that increased salt concentration lowers the freezing point of water; therefore the temperature would now need to be lower for the water to turn into ice (click here for more information).

Impacts of Climate Change on Lake Superior, USA – May 11th, 2013

47.0N 86.3W

May 11th, 2013 Category: Image of the day, Lakes

USA – May 10th, 2013

Researchers have discovered that Lake Superior is one of the most rapidly warming lakes in the world. The lake has lost 79% of its ice cover and lake levels have fluctuated below the long-term average since an extreme drought beginning in 1997-98. The impacts of climate changes like these and other changes could significantly affect the human and natural environments in the Lake Superior basin.

Changes in the amounts of snow melt and rain affect water levels in Lake Superior and inland lakes. These changes have implications for shoreline management and protection including uncertainty about changes to erosion processes.

Increased stormwater runoff and sedimentation of rivers, streams, and bays during extreme flooding, as seen in Duluth, Thunder Bay, and Wawa in the summer of 2012. The economic viability of harbors and marinas may be at risk when water levels change dramatically. For example, lowered water levels may require expensive dredging to maintain boating and shipping operations.

Increased temperatures impact ecological functions and put all natural resources, associated values, and benefits at potential risk. Higher temperatures may also impact the economy and Lake Superior basin communities.

Increased evaporation of surface waters due to drought or reduced precipitation affects water levels, which can reduce recreational boating and the shipping industry.

Decreased ice cover due to higher winter temperatures affects recreational fishing and the tourist industry, water transportation such as ferries, and helps to keep the water warmer for a longer time, which can lead to a negative feedback loop.
Extreme weather events such as flooding, high winds, or significant snowfalls may result in effects on human health and well-being, as well as cause negative economic impacts (click here for more information).

Sediments and Phytoplankton in the Black Sea – May 10th, 2013

42.8N 38.3E

May 10th, 2013 Category: Image of the day, Lakes, Sediments

Black Sea – May 9th, 2013

Swirls of light blue and green phytoplankton and sediment are visible near the shores of the Black Sea. The Black Sea drainage basin encompasses almost one third of Europe, and each year an estimated 350 km3 of runoff enters the Black Sea, bringing substantial sediment and into the semi-enclosed waters. With these sediments come nutrients and fertilizers, which encourage the growth of phytoplankton.