Showing posts with label Dams. Show all posts
Showing posts with label Dams. Show all posts

Sunday, 28 June 2026

Three dead and two missing following flash flood in Arunachal Pradesh.

Three people have been confirmed dead and another two are missing following a flash flood in the Keyi Panyor District of Arunachal Pradesh State, India, on Wednesday 24 June 2026. A further 54 families have been displaced by the incident, in which waters from the Rangandani River Dam Lake over-topped a wall surrounding a residential camp for employees of the North Eastern Electric Power Corporation working on the Panyor Lower Hydroelectric Project (also known as the Rangandani Dam), following days of heavy rain associated with the Summer Monsoon. 

Damage caused by a flash flood which swept through a residential block for workers at a hydroelectric dam in Arunachal Pradesh, India, on 24 June 2026. ANI.

About thirty houses were destroyed at the dam workers colony, with another ten houses destroyed and fourteen damaged in related incidents in neighbouring communities, which have also been hit by flooding and landslide events caused by heavy rains in the area. Landslides are a common problem after severe weather, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall. Several major roads in the area have also been damaged, and the heavy rains are making air transport difficult, hampering the efforts of rescue workers.

Arunchal Pradesh has a monsoon season that begins around the end of April or beginning of May and ends around September, bringing 2-4000 mm of rain to the region each year. In the twenty four hours prior to the incident, 74 mm of rainfall had fallen in the area, which is high, but should not have been sufficient to cause flooding at a camp with flood defences on a dam lake where the water level can be controlled to some extent by releasing water from the dam. This has led to speculation that an earlier incident, such as a landslide, may have temporarily blocked the flow of the river upstream of the dam lake, and that when this temporary blockage failed, a large amount of water surged downstream overcoming the colony's flood defences.

Monsoons are tropical sea breezes triggered by heating of the land during the warmer part of the year (summer). Both the land and sea are warmed by the Sun, but the land has a lower ability to absorb heat, radiating it back so that the air above landmasses becomes significantly warmer than that over the sea, causing the air above the land to rise and drawing in water from over the sea; since this has also been warmed it carries a high evaporated water content, and brings with it heavy rainfall. In the tropical dry season the situation is reversed, as the air over the land cools more rapidly with the seasons, leading to warmer air over the sea, and thus breezes moving from the shore to the sea (where air is rising more rapidly) and a drying of the climate. 

Diagrammatic representation of wind and rainfall patterns in a tropical monsoon climate. Geosciences/University of Arizona.

This situation is particularly intense in South Asia, due to the presence of the Himalayas. High mountain ranges tend to force winds hitting them upwards, which amplifies the South Asian Summer Monsoon, with higher winds leading to more upward air movement, thus drawing in further air from the sea. However, despite the incidents in Arunachal Pradesh this week, the Indian Monsoon is predicted to be be week this year, due to a developing el Niño system over the southern Pacific Ocean, leading to concerns that the country could suffer widespread droughts and famine this year.

The el Niño is the warm phase of a long-term climatic oscillation affecting the southern Pacific, which can influence the climate around the world. The onset of el Niño conditions is marked by a sharp rise in temperature and pressure over the southern Indian Ocean, which then moves eastward over the southern Pacific. This pulls rainfall with it, leading to higher rainfall over the Pacific and lower rainfall over South Asia. This reduced rainfall during the already hot and dry summer leads to soaring temperatures in southern Asia, followed by a rise in rainfall that often causes flooding in the Americas and sometimes Africa. Worryingly climatic predictions for the next century suggest that global warming could lead to more frequent and severe el Niño conditions, extreme weather conditions a common occurrence.

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Sunday, 9 November 2025

Lutra perspicillata: Smooth Coated Otter confirmed within the Papikonda National Park, Andhra Pradesh.

The Smooth Coated Otter, Lutra perspicillata, is one of three species of Otter found in India, along with the Asian  Small-clawed  Otter, Aonyx cinereus, and the Eurasian Otter, Lutra lutra. It is found in Assam, Arunachal Pradesh, Andhra Pradesh, Bihar, Gujarat, Himachal Pradesh, Kerala, Madhya Pradesh, Maharashtra, Punjab, Rajasthan, Uttar Pradesh, Tamil Nadu, and West Bengal states, but has suffered from a declining population due to habitat loss, poaching, pollution, and the eutrophication of waterways. The species is classified as Vulnerable under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species.

In Andhra Pradesh, Smooth Coated Otters are known from the East Godavari, West Godavari,  and Visakhapatnam districts, as well as the Krishna Wildlife Sanctuary, all on the state's northeastern coastal plain. There have also been unconfirmed reports of the species in the Papikonda National Park in the Papi Hills, inland of that coastal plain, although this has not, to date, been confirmed.

In a paper published in the Journal of Threatened Taxa on 26 September 2025, Arun Kumar Gorati, Ritesh Vishwakarma, Anukul Nath, and Parag Nigam of the Wildlife Institute of India, detail the first confirmed sighting of a Smooth Coated Otter in the Papikonda National Park, backed up with photographic evidence.

The Otter was spotted resting on a sandbank exposed by low summer water levels on the Godavari River, about 5 km above the Polavaram Dam Project, slightly before 6.00 pm local time on 12 June 2024. It remained on the bank for about a minute, before entering the water and not being seen again.

A Smooth Coated Otter, Lutra perspicillata, on a sandbank on the Godavari River in the Papikonda National Park on 12 June 2024. Gorati et al. (2025).

As well as being of value in themselves, Otters are an important environmental indicator, demonstrating that the river has a healthy year-round Fish population, capable of supporting piscivorous predators.

However, this ecosystem is currently threatened by the development of the  Polavaram Dam Project. First conceived in the 1940s, work began on the project in the 1980s, with the aim of creating an irrigation system which will provide 2900 km² of farmland and 2 850 000 people with a reliable water supply, and produce hydroelectric power system capable of providing electricity to the entire State of Andhra Pradesh. However, when completed the dam should create a lake covering 631 km² of land, including much of the Papikonda National Park and the traditional lands of the Kondareddy people (considered to be a Particularly Vulnerable Tribal Group), who have been fighting to gain compensation for the planned losses. The project halted in 2019, due to a lack of funds and a flood which damaged a diaphragm wall, but work resumed in 2024, and the project is currently on course for completion in 2027. It already holds the record for the most concrete used for a single project in Human history.

The Polavaram Dam Project under construction. Hindustan Times.

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Monday, 3 June 2024

Four confirmed deaths and thousands evacuated in flooding in southern Germany.

Four people have been confirmed dead and several more are missing as thousands of emergency workers battle flooding across much of southern Germany. The first fatality is reported to have occurred when a 22-year-old firefighter drowned after a rescue boat capsized in the town of Pfaffenhofen der Ilm in Bavaria, which has been subject to some of the worst flooding, following the failure of two dams on the River Paar, a tributary of the Danube. The second is was of a 43-year-old woman who became trapped in a cellar in Upper Bavaria. The remaining two deaths were also of people trapped in a basement, in Schorndorf in the Rems-Murr. Parts of the states of Baden-Württemberg and Bavaria have recorded rainfalls of 130 mm and 129 mm within 24 hours respectively on Friday 31 May 2024, compared to averages for the states of 118 mm and 101 mm for the entire month of May. Parts of the national rail and autobahn network have been forced to close due to flooding, and authorities are advising against non-essential travel to the affected regions.

Flooding in the town of Lauingen in Bavaria on Saturday 1 June 2024. Stefan Puchner/DPA/Picture Alliance.

This is the fourth significant outbreak of flooding in Germany this year, a continuation of a pattern that has been emerging over the past few years. In 2021 flooding in the Rhineland Palatinate cost 135 people their lives and made 1700 homeless. The flooding has been caused by far higher levels of rain falling across central Europe, which in turn is driven by high temperatures over the Atlantic, leading to higher rates of evaporation. 

Flooding in the town of Reichertshofen in Bavaria. Sven Hoppe/DPA.

The high temperatures experienced in the past year have been linked to a combination of anthropogenic global warming, driven by emissions of carbon dioxide and methane, with an El Niño - Southern Oscillation climate system over the Pacific Ocean, a natural phenomenon which also tends to drive temperatures upwards. However, the El Niño system appears to have been weakening over the past months, with sea surface temperatures over the eastern equatorial Pacific actually being lower than the average for 1990-2020, while global temperatures have continued to rise, suggesting that the El Niño system may be playing as large a role in driving this year's high temperatures as previously assumed.

Germany is currently the world's sixth largest producer of greenhouse gasses, and the largest in Europe, producing around 640 000 megatons of carbon dioxide per year, an amount surpassed only by China, the United States, India, Russia, and Japan. In theory the country has set ambitious plans to cut greenhouse gas emmissions by 65% of 1990 levels by 2030, and becoming carbon neutral by 2045. but it is now thought very unlikely that this can be achieved.

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Saturday, 1 June 2024

Musankwa sanyatiensis: A new species of Massopodan Sauropodomorph from the Late Triassic of Zimbabwe.

The Upper Karoo Group deposits of South Africa and Lesotho have produced numerous Late Jurassic and Early Jurassic Dinosaur fossils, contributing considerably to our understanding of the early evolution of the group. Deposits of similar ages are known from across much of Southern and East Africa, although these have been less thoroughly explored by Palaeontologists. Such deposits are present in the Kalahari Karoo Basin of Botswana (where no identifiable Vertebrate remains have been found), Waterberg-Erongo region of Namibia (from which a partial skeleton attributed to the Prosauropod Massospondylus sp. has been described), and the Mana Pools Basin of Zambia (which have yielded a single partial Sauropodomorph). 

In Zimbabwe, Upper Karoo Group sediments are found in the Tuli, Mana Pools, Cabora Bassa, and Mid-Zambezi basins, all of which have yielded Dinosaur fossils. These deposits are capped off by flood basalts, of equivalent ag to the Drakensburg Group, which can be dated to between approximately 176 and 186 million years ago, giving a minimum age to any fossils found in the deposits below. As in other areas of Southern Africa, the most abundant Dinosaurs are Protosauropods, with most specimens assigned to Massospondylus sp., although none of the Zimbabwean material has been compared in any detail to the South African type material. This means that the presence of the taxon in Zimbabwe cannot actually be confirmed, which is important as it has been used as a major piece of evidence in the comparative dating of the two areas. Other Zimbabwean Protosauropods have been assigned to Euskelosaurus (though this is now considered dubious), Vulcanodon karibaensis, and Mbiresaurus raathi, both of which are only known from Zimbabwe. A number of Early Theropod skeletons have also been described from Zimbabwe, all of which have been assigned to the Coelophysoid 'Syntarsus' rhodesiensis.

In a paper published in the journal Acta Palaeontologica Polonica on 30 May 2024, Paul Barrett of the Fossil Reptiles, Amphibians and Birds Section at the Natural History Museum, and the Evolutionary Studies Institute at the University of the WitwatersrandKimberley Chapelle of the Department of Anatomical Sciences at Stony Brook University, and the  Evolutionary Studies Institute at the University of the Witwatersrand, Lara Sciscio of the Jurassica Museum, Timothy Broderick of Harare, Michel Zondo of the Natural History Museum of Zimbabwe, Darlington Munyikwa of National Museums and Monuments of Zimbabwe, and Jonah Choiniere, again of the Evolutionary Studies Institute at the University of the Witwatersrand, Johannesburg, describe a new species of Sauropodomorph Dinosaur from the Pebbly Arkose Formation of Spurwing Island on Lake Kariba, Zimbabwe.

The new species is named Musankwa sanyatiensis, where 'Musankwa' is the name of the houseboat used in two expeditions to Lake Kariba in 2017-18, and means 'boy close to marriage' in the Tchitonga language of the BaTonga people, who inhabited the land flooded by Lake Kariba following the construction of the Kariba Dam, and 'sanyatiensis' means 'from Sanyati' in reference to the Sanyati River Basin, which was flooded by the formation of Lake Kariba, which Spurwing Island was once part of.

(A) Map showing the geographic setting of the Mid-Zambezi Basin in northwest Zimbabwe. (B) Position of Spurwing Island relative to the Zimbabwean (southern) shoreline of Lake Kariba. (C) Spurwing Island; arrow indicates the fossil locality at the Spurwing East Palaeosol site. (D) =Sedimentology of the Spurwing East Palaeosol site. (E) Articulated hind limb of Musankwa sanyatiensis (NHMZ 2521) as discovered in situ. (F) Evidence of bioturbation in the form of invertebrate traces (e.g., Taenidium isp. with menisci highlighted by red mudstone). (G) Associated sediments of the fossil site: pedogenically-modified fines with desiccation cracks, carbonate nodules, and colour mottling. Abbreviations: f, fine; m, medium; vf, very fine. Barrett et al. (2024).

The species is described from a single partial right hind limb, consisting of a complete femur, tibia, and astragalus, with associated indeterminate bone fragments, discovered by Paul Barret during an expedition to the southern shore of Lake Kariba in March 2018. At the time of its discovery it was weathering out of the rock, with the preserved elements still in an articulated state. The whole specimen is heavily sun-cracked and weathered, with poor surface preservation that mightreflect a long period of surface exposure prior to collection,- as well as pre-burial damage. Following collection the limb was placed in the collection of the Natural History Museum of Zimbabwe, and given the specimen number NHMZ 2521.

Right hind limb of the sauropodomorph dinosaur Musankwa sanyatiensis (NHMZ 2521) from the Pebbly Arkose Formation (Norian, Upper Triassic) of Spurwing Island, Zimbabwe. (A) Right femur in posterior (A₁), lateral (A₂), anterior (A₃), medial (A₄), proximal (A₅), and distal (A₆) views. (B) Right tibia with conjoined astragalus in anterior (B₁), lateral (B₂), posterior (B₃), medial (B₄), and proximal (B₅) views. Barret et al. (2024).

Specimen NHMZ 2521 shows no unique features not seen in other Protosaurpods, which is unsurprising given the limited nature of the material available, but does show a sufficiently unique combination of features that Barrett et al. feel comfortable in describing it as a new species and genus. A phylogenetic analysis recovered Musankwa sanyatiensis as the earliest-branching member of the Massopoda, a paraphyletic 'grade' which gave rise to the Sauropods (the Massopoda is considered paraphyletic because all members of the group are descended from a single common ancestor, but not all descendents of that ancestor are considered to be members of that group). However, Barret et al. note that the phylogeny of the Massapoda is poorly resolved, and prone to changing each time a new specimen is found, due to the fragmentary nature of many of the specimens from which species assigned to the group have been described.

Time-scaled reduced strict consensus of over 10 000 maximum parsimony phylogenetic treess with lengths of 1669 steps resulting from inclusion of Musankwa sanyatiensis. Barrett et al. (2024).

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Monday, 6 May 2024

At least eighty three dead in flooding in Rio Grande do Sul State, Brazil.

Eighty three people have now been confirmed dead, and more than a hundred are missing, in a series of floods which have swept across Rio Grande do Sul State, Brazil, over the past week. About two thirds of the 497 cities in the state have been affected since the seasonal rains began on Saturday 27 April 2024, with about 115 000 people forced to flee their homes. The worst single incident happened when a hydro-electric dam between the cities of Bento Gonçalves and Cotiporã collapsed, killing more than 30 people. 

Flooding in the city of Canoas in Rio Grande do Sul State, Brazil, on 5 May 2024. Amanda Perobelli/Reuters.

The flooding is the worst recorded in 150 years of records in Rio Grande do Sul State, exceeding even the floods of 1941, when more than 800 mm of rain fell in parts of the state over a period of 24 days, causing water levels on the Guaíba River to rise by 4.63 m above normal levels in Porto Alegre, the state capital, or 1.63 m above the deck at the city's main port, causing 70 000 people in the city to lose their homes. This year more than 300 mm of rain has fallen in a week, with parts of the state receiving more than 150 mm in under 24 hours, and the Guaíba River has risen by 5.30 m in Porto Alegre.

Flooding in Porto Alegre, the Rio Grande do Sul state capital, on 5 May 2024. Rennan Mattos/Reuters.

The flooding is thought to be caused by a combination of a strong el Niño system over the Pacific Ocean, and this years exceptionally strong global temperatures, which are a result of the rising levels of greenhouse gasses (carbon dioxide, methane, and water) within the Earth's atmosphere, a direct result of Human activities, although Brazil is thought to contribute only about 3% of global greenhouse gas emissions.

Flooding in the Navegantes neighbourhood of Porto Alegre, Rio Grande do Sul, on 4 May 2024. Carlos Fabal/AFP/Getty Images

The el Niño is the warm phase of a long-term climatic oscillation affecting the southern Pacific, which can influence the climate around the world. The onset of el Niño conditions is marked by a sharp rise in temperature and pressure over the southern Indian Ocean, which then moves eastward over the southern Pacific. This pulls rainfall with it, leading to higher rainfall over the Pacific and lower rainfall over South Asia. This reduced rainfall during the already hot and dry summer leads to soaring temperatures in southern Asia, followed by a rise in rainfall that often causes flooding in the Americas and sometimes Africa. Worryingly climatic predictions for the next century suggest that global warming could lead to more frequent and severe el Niño conditions, extreme weather conditions a common occurrence.

The movement of warm water in the Pacific during an el Niño event. NOAA.

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