Deserts

30/03/2018, Oman, Wadi system in Dhofar On 19 March 2014 and 30 March 2018, PROBA-V observed a wadi system in the Dhofar region of Oman. Originally, the Arabic term ‘wadi’ referred to ‘valley’, but nowadays it refers to dry riverbeds that only contain water after heavy rains. The branched Dhofar wadi system is visible in white, just to the south of the Rub’al Khali or “Empty Quarter”, the largest contiguous sand desert in the world which is visible in yellow. The red dots in the images are pivot irrigation fields of the Shisr/Wubar oasis. For about 15 centuries, this agricultural oasis and caravan site was a very important water supply station for the frankincense transportation routes from the inland to the ports along the coast.	, Oman, Wadi system in Dhofar On 19 March 2014 and 30 March 2018, PROBA-V observed a wadi system in the Dhofar region of Oman. Originally, the Arabic term ‘wadi’ referred to ‘valley’, but nowadays it refers to dry riverbeds that only contain water after heavy rains. The branched Dhofar wadi system is visible in white, just to the south of the Rub’al Khali or “Empty Quarter”, the largest contiguous sand desert in the world which is visible in yellow. The red dots in the images are pivot irrigation fields of the Shisr/Wubar oasis. For about 15 centuries, this agricultural oasis and caravan site was a very important water supply station for the frankincense transportation routes from the inland to the ports along the coast.	30/03/2018, Shishr, Oman In March 2018, PROBA-V captured this beautiful image of the confluence of wadis, or valleys, in the Dhofar region of Oman. The wadi system is just to the south of the the Rub’al Khali or “Empty Quarter”, the largest contiguous sand desert in the world. The agricultural oasis of Shishr (or Wubar), with pivotal irrigation using aquifer water, stands out in red. Its name bares reference to a sink hole or well. The site shows remnants of a fortified water stop, used in the ancient caravan trade routes for frankincense. This resin was produced in the wadis and distributed through the ports of Khor Rori and Al Baleed for over 15 centuries. In the KidSat project, American students, using Remote Sensing techniques, including LandSat and SPOT satellite imagery, contributed to the discovery of the ancient roads under the sands, back in the late 1990s.	03/11/2017, Fezzan region, Libya Soil provides important living space for humans, vegetation and wildlife, as illustrated in our recent blogs on Land Cover mapping with PROBA-V, with increasing competition between the different land uses. Soils also play key roles in water management (e.g. soil sealing), in our climate (carbon sequestration), health (e.g. contamination) and in cultural services. This year’s theme of the United Nations’ World Soil Day draws attention to the pressing issues affecting soils, and in particular the positive contributions that pulse crops make to soils by helping to fix nitrogen and boost soil fertility. A true symbiosis, that links well within UN-FAO’s International Year of the Pulses. This weeks PROBA-V image, shows us the inhospitable Sahara desert in the Fezzan region in southwest Libya, where a sprinkling of remote oases enabled ancient towns and villages to thrive. More recently, the northern and southern borders of the Sahara are the scene of significant development efforts and partnerships to combat desertification and contribute to a land-degradation free world.
25/03/2017, Baia California, Mexico The 100 m false-colour image of 25 March 2017 shows us the Colorado River Delta with surrounding desert. It is a region where the Colorado River flows into the Gulf of California (also known as the Sea of Cortez). Historically, the interaction of the river’s flow and the ocean’s tide created a dynamic environment, supporting freshwater, brackish, and saltwater species. Within the delta region, the river split into multiple braided channels and formed complex estuary and terrestrial ecosystems. Use of water upstream and the accompanying reduction of fresh water flow has resulted in loss of most of the wetlands of the area, as well as drastic changes to the aquatic ecosystems. However, a scheme is currently in place which aims to rejuvenate the wetlands by releasing a pulse of water down the river delta.	02/01/2017, Al Ahsa, Saudi Arabia The 100 m false-colour image of 2 January 2017 shows us Al Ahsa, the largest governorate in Saudi Arabia's Eastern Province, named after the Al-Ahsa oasis, a traditional oasis region in eastern Saudi Arabia and one of the largest oases in the world. Ahsa means the sound of water underground referring to the springs and freshwater sources in the Al-Hasa oasis. In the right part of the image we spot Umm al Samim, an area of quicksand on the eastern edge of the Rub al-Khali. It is a salt marsh with a solid-looking crust but can be very treacherous when broken through.	27/08/2016, Cape Horn, Africa The 300 m false-colour image of 27 August 2016 shows us Puntland, a region in northeastern Somalia. Puntland is bordered by the self-declared Republic of Somaliland to its west, the Gulf of Aden in the north, the Indian Ocean in the southeast, the central Galmudug region in the south, and Ethiopia in the southwest. The exact location of the fabled territory is still a mystery. Many studies suggest that the Land of Punt was located in present-day Somalia, whereas others propose that it was situated elsewhere. The region is semi-arid, with a warm climate and average daily temperatures ranging from 27 °C to 37 °C. Rainfall is sparse and variable, with no single area receiving more than 400 mm of rain annually.	06/06/2016, Aoukar, Mauretania On June 17, 2017, the United Nations draw our attention to the international cooperation that is the key for the implementation of the UN Convention to Combat Desertification, in particular in Africa. In June last year, PROBA-V captured this image of southeast Mauretania, a country in western Africa that is three quarters desert or semi-desert. It shows steep slopes and cliffs at the eastern edge of the Aoukar basin, once a reed-covered lake that supported a civilization at its shores between 1700 and 400 BC. Today, Aoukar is a dry, natural region of sand dunes and salt pans. Prolonged drought, aggrevated by poor land management, such as deforestation and over-grazing, resulted in a southward expansion of the Sahara in the country since the 1960s. By the 1980s, the desert threatened human settlements and moved pastoralism. To combat the desertification, the government constructed dams and planted palm trees, with international aid.
02-09/2016, Sahel, Africa The Sahel region is the semi-arid transition zone, dominated by grasslands and acacia savanna, located between the Sahara desert and the tropical savanna. The Sahel stretches more than 5,000 km across Africa, from the Atlantic Ocean (Senegal, Mauritania) to the Red Sea (Sudan). The few months of rainy season in the Sahel are much needed in these hot and sunny parts of Africa and key factor for the food security and livelihood of the people. The name Sahel can be translated from Arabic as coast or shore, painting us the picture of the moving shoreline between vegetation and the desert along the year, as exemplified by this pair PROBA-V 300m images. They were captured in February(top), in the dry season, and September(bottom), towards the end of the Sahelian rains.	10/06/2016, Sahara Desert, Mauritania In the sands of the Sahara Desert, in central southern Mauritania, a long sandstone cliff formation marks the edge between the depression that remains from the ancient Aoukar lake (to the south) and the Tagant Plateau. This PROBA-V image highlights the contrast between the sand dunes of the depression, the dark-coloured slopes and the stony plateau. In this barren and hot area, along the slopes, a number of historical towns are being encroached by the desert. One example is the fortified village or ksour of Tichit (further to the east), protected as World Heritage Site by UNESCO for its value to Islamic culture, religion and trans-Sahara trade. Even older sites of archaeological importance, such as Dhar Tichit, are found in the area as well, dating back until 3000 to 2500 years ago, when the area had a more temperate climate.	18/05/2016, Eye of the Sahara, Mauretania A large circular formation in the Sahara desert of Mauretania. That is the Eye of the Sahara, also known as the Richat Structure or Guelb er Richat. Walking on it, eye cannot tell you would make much of it, but since it has been spotted from space it has given us various surprising satellite images. The deeply eroded, slightly elliptical dome has a diameter of 40 km and was initially interpreted as a meteorite impact and then a structure formed by a volcanic eruption. Both are impossible because of the lack of a dome of igneous or volcanic rock. Some people now believe it has been caused by uplifted rock sculpted by erosion. The Eye of the Sahara has become a landmark for shuttle crews and gives us some amazing views of our Earth’s surface. PROBA-V captured this 100 m image on May 18, 2016. You can clearly see the circular structure, the equidistant rings of the bull’s-eye as well as the rather featureless expanse of the desert.	25/06/2016, Niangay, Mali This week’s false-colour image shows the interplay of emergent sand ridges, canals and lakes, such as Lake Fati, Lake Niangay, Lake Do and Lake Aougoundou in the northern part of the Inner Niger Delta in Mali. Just south of the Sahara Desert, the Delta forms an oasis amidst its semi-arid surroundings and sustains for instance palm and gum arabic trees on the ridges and the African manatee (sea cow) in the rivers. The Niger River, flowing in its atypical curve-shape, is the source of livelihood for many Sahelians. This portion of the river flows northward between the grasslands on the floodplains of the lower Inner Niger Delta and the familiar town of Timbuctu to the northeast. Lake Niangay, the largest lake in this daily synthesis image, is the second largest lake of Mali and is about to be refilled by the July-October rainy season.
06/03/2016, Ténéré, Niger The Ténéré region in north-eastern Niger is one of the hottest and driest regions in the Sahara desert, with average maximum temperatures above 40°C between May and September and average annual precipitation 20 – 25 mm. Due to the persistent high-pressure area that causes descending and drying air, the region is one of the sunniest on Earth, with the annual sunshine duration around 4,000 hours. The region’s geography largely consists of planes with sand dunes (ergs) that are oriented perpendicular to the persistent north-easterly wind (Harmattan). The area also contains some oasis settlements, such as the city of Bilma. The 100 m image of 6 March 2016 shows the extensive sand dunes as yellow areas in the upper image part, with the sand and dust being transported towards the southwest, visible as faint feather-like structures.	11/05/2015, Okavango Delta, Botswana The 100 m false-colour image of 11 May 2015 shows us the Okvango Delta in Botswana. It is a very large inland delta formed where the Okavango River reaches a tectonic trough in the central part of the endorheic basin of the Kalahari. All the water reaching the Delta is ultimately evaporated and transpired, and does not flow into any sea or ocean.	07/01/2015, Coast of Turkmenistan The 100 m false-colour image of 7 January 2015 shows us the west-coast of Turkmenistan, a country in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north and east, Afghanistan to the southeast, Iran to the south and southwest, and the Caspian Sea to the west. The climate is mostly arid subtropical desert, with little rainfall. Winters are mild and dry, with most precipitation falling between January and May. In the image you can see the Karakum desert, which is one of the world's driest places and covers about 80% of the land of Turkmenistan.	18/01/2015, Tahoua Region, Niger The 100 m false-colour image of 18 January 2015 shows us Tahoua, one of eight administrative Regions in Niger. The capital of the Region is the Commune of Tahoua. On top of this image we can see a dried up river. Seasonal rains are increasingly unreliable in the Sahel due mainly to climate change. At the left, we see the Gagere river, a tributary leading to the Rima River, Sokoto River and Niger River. In the middle of the image flows the Goulbi de Maradi River, a seasonal river and flows only during the rainy season. Between its source near Katsina in Nigeria, and its end in the Rima River, the Goulbi de Maradi never flows more than 48 kilometres from the Niger–Nigeria border. Though important for agriculture and pastoralism, and flowing through the Niger cities of Maradi, Guidan Roumdji, and Madarounfa.
05/09/2015, Dasht-e Kavir, Iran The 100 m false-colour image of 5 september 2015 shows us a colourfull view of Dasht-e Kavir. The desert soil is covered with sand and pebbles; there are marshes, seasonal lakes and seasonal river beds. The hot temperatures cause extreme vaporization, which leaves the marshes and mud grounds with large crusts of salt. Heavy storms frequently occur and they can cause sand hills reaching up to 40 m in height. Some parts of Dasht- e Kavir have a more steppe-like appearance.	11/10/2015, Namib-Naukluft Natioan Park, Namibia The 100 m false-colour image of 11 October 2015 shows us the Namib-Naukluft National Park, encompassing part of the Namib Desert. The winds that bring in the fog are also responsible for creating the park’s towering sand dunes, whose burnt orange color is a sign of their age. The orange color develops over time as iron in the sand is oxidized, like rusty metal; the older the dune, the brighter the color. These dunes are the tallest in the world, in places rising more than 300 meters above the desert floor.	14/10/2015, Waw an Namus, Libya The 100 m false-colour image of 11 October 2015 shows us Waw an Namus, in the southern Fezzan region of southern Libya. A volcanic field of dark basaltic tephra with flow extends up to 10–20 kilometres around the caldera. The dark field's vast size allows it to be easily seen from space.	28/02/2016, Mopti region, Mali The 100 m false-colour image of 28 February 2016 shows us a nice view of the Tombouctou and Mopti region. Tombouctou Region is one of the administrative regions of Mali. It is the largest of Mali's eight regions and includes a large section of the Sahara Desert. Mopti Region, another administrative region of Mali, bordered by Tombouctou Region to the north, Ségou Region to the southwest, and Burkina Faso to the southeast. The Niger River crosses the region, and is joined by the Bani, an important tributary, at the city of Mopti. Tombouctou region is world-famous for its capital, the ancient city Timbuktu, synonymous to 19th-century Europeans as an elusive, hard-to-reach destination.
01/03/2016, Illizi, Algeria The 100 m false-colour image of 1 March 2016 shows us Illizi, a town and commune, situated in the south-eastern part of Algeria, and capital of Illizi Province. It has a hot desert climate, with long, extremely hot summers and short, very warm winters. The town is virtually rainless throughout the year as the average annual rainfall is around 10 mm, and summers are especially dry. The sky is always clear over Illizi all year long and the relative humidity is very low.	01/03/2016, Pivot irrigation fields, Libya The 100 m false-colour image of 1 March 2016 shows us Sabha, one of the districts of Libya. It is located near the center of the country, in the Fezzan region with many irrigation fields. The method known as Pivot irrigation proves one more time that good investments generate great results. In a country like Libya, where more than 95% of the country consists of the near-waterless Sahara, this type of agriculture is not cheap, and is only possible by being able to tap underground fossil water deposits from a large underground aquifer. Each circular plot is about one kilometer in diameter and is able to grow different kind of crops: corn, cereals, fruits, peanuts, vegetables, crops for animal fodder…	01/03/2016, Arlit, Niger The 100 m false-colour image of 1 March 2016 shows us Arlit. It is an industrial town and capital of the Arlit Department of the Agadez Region of northern-central Niger. It is 200 km south by road from the border with Algeria. Founded in 1969 following the discovery of uranium, it has grown around the mining industry. 40% of Niger's uranium production came from Arlit, and uranium represented 90% of Niger's exports. A major modern road, known as the Uranium Highway, has been built to transport uranium south, but it has bypassed many towns along the way (In-Gall for example) and has radically changed Niger's transportation system. Arlit has a hot desert climate.	16/03/2015, Simpson Desert, Australia Deserts are commonly monitored for a variety of applications on drought and surface energy. An example is the large erg of the Simpson Desert, Australia, a popular landmark in Winter, thanks to numerous water springs, while closed-off in Summer due to high temperatures and sand storms. The Desert is filled with a pattern of north-south oriented sand dunes, up to 200 km long and 40 m high and displaying a wide range of colours, from brilliant white to dark red, including pinks and oranges. The interlace of dunes and water provides a striking colour palette in the PROBA-V 100 m image from the middle of March 2015.
04/02/2016, Rann of Kutch, India The PROBA-V daily synthesis of early February this year further shows us the Pakistan’s Keti Bunder South Wildlife Sanctuary, with a network of rivers and river mouths and several lakes, with Shakoor Lake as the most prominently visible.	16/06/2015, Telfer, Australia Telfer is a town in western Australia, located in the Great Sandy Desert. Daily maximum temperatures regularly approach 50°C and the average annual rainfall is 370mm. The town was founded in 1975 around a gold and copper mine. Since then, more than 280,000 kg of gold have been digged. The different colour patches in the image indicate the various mining sites.	27/07/2015, Dasht-e-Lut, Iran The 100 m false-color image of 27 July 2015 shows the desert's central part on the left as yellowish paint strikes, while the eastern sand desert is visible as a light-brown area. Further, some irrigated land can be seen on the image's left-side as bright green areas.	17/05/2015, Atacama desert, Chile The 100 m image of 17 May 2015 shows the Chilean north coast area and the dry river valleys in the left part. The blue-green area in the right part is the Salar du Surire, a salt plain containing several lakes with nesting flamingo colonies. Just northeast of this plain, the Pukintika volcano (5,407 m) is visible as a light-blue area.
26/05/2015, Saudi Arabia, Medina Medina is a city in the Hejaz, and the capital of the Al Madinah Region of Saudi Arabia. The city contains al-Masjid an-Nabawi ("the Prophet's mosque"), which is the burial place of the Islamic prophet Muhammad and the second-holiest site in Islam after Mecca. The 100 m false color image shows the city (in the centre) and its surroundings. To the south of Medina, some old volcanic fields are visible.	01/06/2015, Sahel, Mali The 100 m image of 1 June 2015 shows the central part of Mali and the Inner Niger Delta near the city of Mopti. Yhe Inner Niger Delta is a bifurcation of the Niger river and one of its tributaries, the Bani river.	08/01/2015, Egypt, Centre pivot irrigation Pivot irrigation is an irrigation form in which water is pumped up from deeper soil layers and subsequently is horizontally distributed by large sprinklers. In various parts of the Saharan and Arabian deserts, these centre pivot systems are easily recognized, as can be seen on this 100 m image taken over the Qesm al Wahat ad Dakhlah region (southern Egypt).	09/11/2014, Sand dunes, Yemen This image shows a large number of sand dunes in the southern part of the Rub al Khali desert (also called the Empty Quarter) in Yemen. The Rub al Khali desert is the world's largest sand desert and covers about 650,000 square kilometres. Underneath the sand dunes, vast oil reserves have been discovered, making the desert the most oil-rich site in the world.
12/01/2015, Kufra Oasis, Libya The Libyan Desert covers areas in western Egypt, southern Libya, and north-western Sudan. While most of this desert comprises sand plains, dunes, ridges, and depressions, especially in southern Libya it has a beautiful diversity of landscapes. An example of such a diversity can be seen in this 100 m image of 12 January 2015, taken near the Libyan-Egypt-Sudan border. It shows some fluent sand dunes mixed with the rough elevations of the Tibesti, a mountain range of volcanic origin.	09/11/2014, Desert irrigation, Saudi Arabia Scattered throughout the Arabian desert many isolated irrigation fields are located. Fossil water is mined to the surface from depths of about 1 km and further distributed via center pivot irrigation feeds. This 100 m image shows some of these fields in the eastern part of Saudi Arabia, surrounded by the extensive desert.	09/11/2014, Irrigation in Arabian desert This 100 m image shows an extensive irrigation field in the southern part of Saudi Arabia, visible in the center. The image further beautifully shows desert sand dunes in the south-east and some wadis in the south-west.	09/11/2014, Riyadh, Saudi Arabia Riyadh is the capital and largest city of Saudi Arabia, populated by about 7 million people. The city has grown explosively from an isolated town into a metropolis since the 1940s. Although located in an area with only ~100 mm of yearly rainfall, the city has sufficient drinking water reservoirs. The reservoirs are replenished from rain water, ground water, and desalinated coastal water. The image shows the Riyadh urban area in the center, surrounded by the Arabian desert to the east and Tuwaiq mountains to the south.
30/09/2014, St Francis Bay, Namibia The Namib is a coastal desert in southern Africa. The name Namib is of Nama origin and means "vast place". According to the broadest definition, the Namib stretches for more than 2,000 kilometres along the Atlantic coasts of Angola, Namibia, and South Africa, extending southward from the Carunjamba River in Angola, through Namibia and to the Olifants River in Western Cape, South Africa. This 100 m image of 30 September 2014 shows the sand dunes in the Namib desert.	13/10/2014, Xinjiang, China Xinjiang is an autonomous region in China. It is the largest Chinese administrative division and the 8th largest country subdivision in the world, spanning over 1.6 million km². Xinjiang borders Russia, Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Afghanistan, Pakistan, India, and TIbet. Xinjiang has abundant oil reserves and is China's largest natural gas-producing region. This image shows the large Taklamakan desert (370,000 km²), surrounded by the Tien Shan mountains to the north and the Kunlun Shan mountains to the south.	25/04/2014, Potash factory, China Lop Nur is a former salt lake in the Chinese Province of Xinjiang, between the Taklamakan and Kumtag deserts. In this vast desert area, something peculiar can be seen in this 100 m image. In the mid-1990s, potash (water-soluble potassium salt) was discovered in this region. Potash is a major plant nutrient, which led to a large mining operation and the building of a factory site. The large rectangular shapes (approximately 10 × 20 km in total), are evaporation ponds that are used to extract the potash from the mined salts. The arc-shaped salt mining patterns can also be seen.	25/04/2014, Man made shapes, China This 100 m image shows part of the Chinese Taklamakan desert in the Barkol Lake region. Two mountain ranges, still covered with snow, show up in the middle and lower part of the image. In the lower right part, Lake Tuolekule is visible. However, the most striking features are the large man-made shapes that are visible in the upper part of the image.
, Saudi Arabia, Medina Medina is a city in the Hejaz, and the capital of the Al Madinah Region of Saudi Arabia. The city contains al-Masjid an-Nabawi ("the Prophet's mosque"), which is the burial place of the Islamic prophet Muhammad and the second-holiest site in Islam after Mecca. The 100 m false color image shows the city (in the centre) and its surroundings. To the south of Medina, some old volcanic fields are visible.