Heavy Sedimentation Flow of Betsiboka River (False Color)
The beautiful Betsiboka river delta is a dramatic example of massive deforestation, that occurs in Madagascar every year. One of the biggest culprits is the slash and burn agriculture, called tavy, where the forest is burnt and then farmed in the following months. The other deforestation causes include grazing, logging and the production of coal. The forest grows back after being cut down, but until then, the barren soil is vulnerable to erosion by heavy rains. The rain transports it into rivers and from their into the sea, contaminating sea life with deposited iron oxides. As soil formation is a process taking thousands of years, soil erodes away each year, until it can no longer support a forest. Due to these processes, Madagascar has already lost 80 % of its primary forests, causing many indigenous species, such as lemurs, to be endangered.
Lake Natron, Tanzania
Natron is a fascinating lake, deadly to most animals, that are not accustomed to its alkaline environment. The dangerously high PH of 10.5 is caused by sodium carbonate flowing in from the surrounding hills, active with volcanism. Sodium carbonate deposits serve as a preservant, calcifying the carcasses of deceased animals. Despite the harsh ecosystem, some species survive here. On its shores, flocks of flamingos, which have evolved leathery skin to tolerate the water, find a safe nesting place, as predators avoid the area. The stunning red color is caused by cyanobacteria, that thrive in the dry season, as salinity rises due to evaporation. Read more here, here and here.
Roper River, Tanzania (Enhanced False Color)
Roper river is over 1.000 km long, and its irrigation potential is considered to be immense. Using the powerful northern rivers is expected to create numerous jobs and greatly contribute to agricultural development and sustainability. However, some worry the project would require a million hectares of the catchment area to be bulldozed for irrigation agriculture, as well as a dam to be built, which could significantly dry up the river. As the impact on the economy is compelling, the project continues regardless. Read more on the catchment area and more on the project here and here.
Algae Blooms of Don River, Russia (Water Quality Viewer)
The Tsimlyansk Reservoir - a big reservoir on the Don River in Russia - is around 250 kilometers long and provides water for a hydropower station, as well as for the irrigation of the surrounding fields. The visualization aims to dynamically visualize the chlorophyll and sediment concentrations in water bodies, the two primary indicators of water quality. Chlorophyll content ranges in colors from dark blue (low chlorophyll content) through green to red (high chlorophyll content). Sediment concentrations are colored brown; opaque brown indicates high sediment content. High chlorophyll and sediment concentrations can both be found on the norther shore, coming from the surrounding agricultural fields. This reduces the reservoir's water quality (pollution, eutrophication, toxification) which poses a risk for the in situ ecosystem.
Salt lake Mackay, Australia
Lake Mackay or Wilkinkarra (in Pitjantjatjara) is the fourth largest lake in Australia, covering an area of 3.494 square kilometers. The particularity of this water body is that being an ephemeral lake, it only fills with water after seasonal rainfall, although water can persist for several months after a major rain event. When inundated, the lake is of significant importance for endemic waterbird populations, who use the freshwater claypans as breeding grounds. Due to evaporation, minerals are carried to the surface, forming bright white salt pans that contrast with the darker brown islands scattered across the eastern half of the lake. On these islands and around the shoreline, bright orange longitudinal sand ridges form stunning lines from east to west across the landscape.
Shark Bay, Australia
Located 800 km north of Perth in the Indian Ocean, Shark Bay is a unique UNESCO World Heritage site. The bay is renown for having the largest seagrass meadow in the world (~4.000 square kilometers), forming a feeding ground for large populations of aquatic life, including dugong. The seagrass can be seen from space in the shallower areas of the bay, contrasting strongly with the dark brown sand on the surrounding land. The water in Shark Bay is up to twice as salty as the sea, forming one of few marine environments in the world with hypersaline waters and hosts stromatolites, colonies of algae that build mounds and are among the oldest forms of life on earth.
Barrier Reef, New Caledonia (Enhanced True Color)
Barrier reef of New Caledonia is protected as a UNESCO World heritage site, due to its outstanding coral reef biodiversity and lagoon beauty. It is comprised of six marine clusters and is one of the three most extensive reef systems in the world. The ecosystems are intact, with healthy populations of great diversity. They provide habitat to a number of emblematic or threatened marine species such as turtles, whales or dugongs whose population here is the third largest in the world. This varied reef landscape ranges from extensive double barrier systems, offshore reefs and coral islands, to the near-shore reticulate reef formations. This beauty continues below the surface with dramatic displays of coral diversity, massive coral structures, together with arches, caves and major fissures in the reefs.
Coastal waves, Tyrrhenian Sea
Coastal waves are a daily consequence of the so-called sea breeze. During the day, the land gets heated from the sun, getting warmer than the sea. As warmer air is less dense, it rises above the land, lowering the air pressure. The difference in air pressure creates cool winds, blowing from the sea towards the land. Italy attracts many tourists interested in surfing, especially in winter, when the waves are expected to be the highest. On December 22, 2019, however, the waves were extremely high due to the storms Elsa and Fabien, which caused winds up to 200 kilometers per hour. The storms caused power outages, heavy flooding and a mini tornado, which destroyed 20 homes. The storm caused 9 fatalities and resulted in considerable damage across Portugal, Spain and France.