Showing posts with label Assam State. Show all posts
Showing posts with label Assam State. Show all posts

Tuesday, 17 May 2022

Three dead and several missing following landslide in Assam State, India.

Three people have died and several more are missing following a landslide in Assam State, India, on Saturday 14 May 2022. The incident happened in the evening when part of a hillslope in Dimo Hasao District collapsed following several days of heavy rain in the area associated with the Indian Monsoon Season. Landslides are a common problem after severe weather events, 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.

 
A landslide in Dimo Hasao District, Assam, which killed at least three people on Saturday 14 May 2022. Press Trust of India.

The incident comes amid widespread flooding in Assam, which has displaced thousands of people in five districts, and at least eighty homes destroyed in 10 villages. Numerous roads and rail lines have been swept away, severely hampering travel within the state. Monsoon Season typically lasts from May to October each year in Assam, and frequently brings with it flooding and related events. However, this year many areas of the state also had unusual pre-monsoonal rains through much of April, which led to the ground already being waterlogged by the time the monsoon arrived, and therefore a much more rapid onset of flooding problems.

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

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. 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.

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Sunday, 2 May 2021

Magnitude 6.4 Earthquake in Assam State, India.

The Indian National Centre for Seismology recorded a Magnitude 6.4 Earthquake at a depth of 17 km, about 43 km to the west of the town of Tezpur in the Sonitpur District of Assam State India, slightly after 7.50 am local time (slightly after 2.20 am GMT) on Wednesday 28 April 2021. The incident was felt across much of northeast India, as well as neighbouring areas of Bangladesh, Bhutan, and Nepal, and caused damage to buildings across the state. There are no reports of any damage or injuries directly attributed to the event, but two people died of heart attacks that may have been triggered by the Earthquake. The event has been followed by numerous aftershocks, several of them with Magnitudes in excess of 4.0.

 
Damage to a building in Assam State, India, caused by an Earthquake on 28 April 2021. Press Trust of India.

Earthquake activity in northeast India is caused by the uplift of the Tibetan Plateau, due to the impact of India into Eurasia to the south. he Indian Plate is moving northwards at a rate of 5 cm per year, causing it to impact into Eurasia, which is also moving northward, but only at a rate of 2 cm per year. The collision of the Indian and Eurasian plates has lead to the formation of the Himalayan Mountains, the Tibetan Plateau, and the mountains of southwest China, Central Asia and the Hindu Kush. 

The approximate location of the 28 April 2021 Earthquake. USGS.

Witness accounts of quakes can help geologists to understand these events and the rock structures that cause them. If you felt this quake you can report it to the Indian National Centre for Seismology here.

 
Block diagram showing how the impact of the Indian Plate into Eurasia is causing uplift on the Tibetan Plateau. Jayne Doucette/Woods Hole Oceanographic Institution.

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Wednesday, 15 July 2020

Flooding kills at least sixty six in Assam State, India.

At least sixty six people have died in flooding in Assam State associated with the annual Monsoon this year. Twenty six of the state's thirty three districts have suffered flooding, with around 3 573 000 people living in affected areas, of whom about 36 000 people from nineteen districts have been forced to flee their homes, and are currently housed in 629 relief camps. A number of animals, including two Rhinoceros, have reportedly drowned in the Kaziranga National Park and Tiger Reserve, which has been hit by severe flooding.

Flooding in Morigaon District, Assam. Press Trust of India.

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. 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. 

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

See also...

https://sciencythoughts.blogspot.com/2020/06/landslide-kills-one-in-guwahati-india.htmlhttps://sciencythoughts.blogspot.com/2020/04/police-arrest-four-men-for-killing.html
https://sciencythoughts.blogspot.com/2020/02/magnitude-50-earthquake-in-assam-state.htmlhttps://sciencythoughts.blogspot.com/2019/11/magnitude-47-earthquake-in-assam-state.html
https://sciencythoughts.blogspot.com/2019/11/elephant-kills-five-villagers-during.htmlhttps://sciencythoughts.blogspot.com/2019/09/suspected-poacher-killed-in-shootout.html
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Sunday, 28 June 2020

Landslide kills one in Guwahati, India.

A woman has died after her house was destroyed by a landslide in the Kharguli area of the city of Guwahati in Assam State, India, on Sunday 28 June 2020. Priyanka Boro, 21, described as a talented performing artist specialising in classical, folk, and Bihu dancing, is believed to have died instantly in the event, which happened after days of heavy rain in the area associated with the Indian Monsoon Season. Landslides are a common problem after severe weather events, 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.

Talented dancer Priyanka Boro, 21, of Guwahati, Assam, and the aftermath of the landslide which killed her on 28 June 2020. Northeast Now.

Guwahati is notoriously prone to landslides, particularly during the summer monsoon season, in part due to the hilly nature of the city, but largely due to the largely unplanned nature of many of the cities poorer districts, with many dwellings erected illegally without any formal planning permission, often on slopes where a thin layer of laterite clay covers a friable, sandy soil, which is prone to collapsing downslope when disturbed.

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.

See also...

https://sciencythoughts.blogspot.com/2020/04/police-arrest-four-men-for-killing.htmlhttps://sciencythoughts.blogspot.com/2020/02/magnitude-50-earthquake-in-assam-state.html
https://sciencythoughts.blogspot.com/2019/11/magnitude-47-earthquake-in-assam-state.htmlhttps://sciencythoughts.blogspot.com/2019/11/elephant-kills-five-villagers-during.html
https://sciencythoughts.blogspot.com/2019/09/suspected-poacher-killed-in-shootout.htmlhttps://sciencythoughts.blogspot.com/2018/06/flooding-kills-23-in-northeastern-india.html
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Friday, 24 April 2020

Police arrest four men for killing a Leopard in Assam State, India.

The police in Golaghat District, Assam, have arrested four men for the killing of a Leopard earlier this month. The four men, Junmon Gogoi, Raktim Gogoi, Thagiram Gogoi and Nitya Nand Saikia, were arrested on Saturday 18 April 2020 after posting footage of the killing, which happened the day before, on social media. The State of Assam has suffered a series of wildlife crimes during the current Coronovirus Epidemic Lockdown, with at least four Leopards, a Wildcat, and an Elephant having been slain.

A Leopard in Assam. Leopards of Assam/Facebook.

Leopards are considered to be Vulnerable under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species, with the Indian subspecies, Panthera pardus fusca, considered to be particularly vulnerable due to India's rapidly rising Human population, which has resulted in agriculture and other Human activities expanding into many former wilderness areas. Trade in Leopard skins is not completely banned internationally, with CITES allowing some African countries to issue permits for trophy hunting of the animals. However, in India Leopards are strictly covered by the Wildlife Protection Act of 1972, and owning Leopard body parts will almost always be treated as a criminal offence.

See also...

https://sciencythoughts.blogspot.com/2020/02/magnitude-50-earthquake-in-assam-state.htmlhttps://sciencythoughts.blogspot.com/2020/01/cuon-alpinus-understanding-distribution.html
https://sciencythoughts.blogspot.com/2019/11/magnitude-47-earthquake-in-assam-state.htmlhttps://sciencythoughts.blogspot.com/2019/11/elephant-kills-five-villagers-during.html
https://sciencythoughts.blogspot.com/2019/09/suspected-poacher-killed-in-shootout.htmlhttps://sciencythoughts.blogspot.com/2018/06/flooding-kills-23-in-northeastern-india.html
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Sunday, 9 February 2020

Magnitude 5.0 Earthquake in Assam State, India.

The United States Geological Survey recorded a Magnitude 5.0 Earthquake at a depth of 10.0 km, about 16 km to the east of the town of Abhayapuri in the Bongaigaon District of Assam State India, slightly after 6.15 pm local time (slightly after 12.45 pm GMT) on Saturday 8 February 2020. The incident was felt across much of northeast India, as well as in Bhutan and northern Bangladesh, but no  damage or casualties have been reported.

The approximate location of the 8 February 2020 Earthquake. USGS.

Earthquake activity in northeast India is caused by the uplift of the Tibetan Plateau, due to the impact of India into Eurasia to the south. he Indian Plate is moving northwards at a rate of 5 cm per year, causing it to impact into Eurasia, which is also moving northward, but only at a rate of 2 cm per year. The collision of the Indian and Eurasian plates has lead to the formation of the Himalayan Mountains, the Tibetan Plateau, and the mountains of southwest China, Central Asia and the Hindu Kush.

Block diagram showing how the impact of the Indian Plate into Eurasia is causing uplift on the Tibetan Plateau. Jayne Doucette/Woods Hole Oceanographic Institution.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organisation Earthquake Report is interested in hearing from people who may have felt this event; if you felt this quake then you can report it to Earthquake Report here.
 
See also...
 
https://sciencythoughts.blogspot.com/2019/11/magnitude-47-earthquake-in-assam-state.htmlhttps://sciencythoughts.blogspot.com/2019/11/elephant-kills-five-villagers-during.html
https://sciencythoughts.blogspot.com/2019/09/suspected-poacher-killed-in-shootout.htmlhttps://sciencythoughts.blogspot.com/2018/06/flooding-kills-23-in-northeastern-india.html
https://sciencythoughts.blogspot.com/2017/07/flooding-kills-at-least-seventy-three.htmlhttps://sciencythoughts.blogspot.com/2016/07/woman-killed-by-landslide-in-guwahati.html
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Monday, 13 January 2020

Cuon alpinus: Understanding the distribution of Dholes in northeast India.

The Dhole, or Asian Wild Dog, Cuon alpinus, is an Endangered social carnivore found in forested landscapes of South and Southeast Asia. Historically widespread across Asia, the species’ range has contracted by about 80%. The current distribution extends across most of South and Southeast Asia and parts of China but is largely restricted to protected areas. The protected forest landscapes south of the River Ganges in India are a stronghold for the species, with the largest Dhole population. However, the species has undergone local extirpation across parts of its former range as a result of declines of prey species, loss of habitat and, potentially, disease. Information on Dholes in northeast India in particular is limited, despite the fact that this landscape shares continuous forest with Myanmar and Southeast Asia, forming an important part of the species' global range.

A Dhole, or Asian Wild Dog, Cuon alpinus. David Raju/Wikimedia Commons.

In a paper published in the journal Orynx on 23 October 2019, Priya Singh of Researchers for Wildlife Conservation at the National Centre for Biological Sciences, and the School of Natural Resources and Environment at the University of Florida, Arjun Srivastha of the Department of Wildlife Ecology and Conservation at the University of Florida, and David Macdonald of the Wildlife Conservation Research Unit at the University of Oxford, provide a compilation of dhole presence records from across northeast India using data extracted from multiple sources.

Current knowledge of Dholes in north-east India is restricted to landscapes north of the River Brahmaputra. This is primarily because of the paucity of baseline ecological data from the region, given its undulating terrain, difficulty of access, wet climatic conditions, and socio-political insurgencies.

Using data from camera-trap surveys Singh et al. examine factors influencing fine-scale site-use by Dholes in Dampa Tiger Reserve in Mizoram State. They discuss the implications of their results for Dhole conservation in northeast India, where the focus of wildlife managers is directed mainly towards population recoveries of and local recolonisation by the Tiger, Panthera tigris. They further provide recommendations for management interventions that could facilitate conservation of Dholes in this hitherto neglected landscape.

Dampa Tiger Reserve lies in the Indo-Myanmar Biodiversity Hotspot. The reserve is contiguous with the Chittagong Hill Tract region of Bangladesh to the west. The core area of the Reserve covers 500 km², and the multi-use buffer covers an area of 488 km². The Lushai Hills traverse the reserve, with altitudes of 250-1100 m. Mean annual rainfall is 2000-2500 mm. The Reserve supports a high diversity of Carnivores, including, in addition to the Dhole, four species of Felids and two species of Ursids. In the course of the study Singh et al. also recorded the Elephant, Elephas maximus, Gaur, Bos gaurus, Sambar, Rusa unicolor, Red Serow, Capricornis rubidus, Muntjac, Muntiacus muntjak, and Wild Pig, Sus scrofa.

Northeast India, with the Dampa Tiger Reserve in Mizoram and locations where the Dhole, Cuon alpinus, has been recorded, with corresponding reliability scores. Singh et al. (2019).

Singh et al. compiled Dhole presence records for nine northeastern states: Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, Tripura, and West Bengal. They searched for records from 1990 onwards in newspaper reports, scientific articles, grey literature (including species checklists), and reports by Forest Department personnel, local informants and naturalists working in the region. For each record they noted the type of evidence (direct/indirect), the date of the sighting, the administrative status of location (protected/non-protected), and the source person or reference. They assigned reliability scores for each record, from 1 to 5, with 1 being most reliable, and 5 least reliable.

From December 2014 to March 2015, Singh et al. deployed 79 pairs of Cuddeback Ambush IR camera traps across 80 km² in the northeast of Dampa Tiger Reserve’s core area. At each station they placed two cameras facing each other, about 30 cm above the ground, on either side of forest trails or on riverbeds. Mean inter-trap distance was 1.02 km, with traps remaining active for an average of 64 days. Although the stations were intended to photograph wild Felids, they also photographed other Carnivores. Dholes generally use forest trails and riverbeds for movement, marking territories and hunting, and our sampling design therefore incorporated areas used by the species.

Singh et al. obtained presence records from 80 locations for 1990-2018, of which we considered 41 records from 2010–2018 with reliability scores of 1-3. In the case of multiple records for the same site, they considered the most recent record with the highest reliability score. Most records were from Arunachal Pradesh (14) and Assam (8), with five records from Mizoram and Nagaland, four from West Bengal, three from Meghalaya and two from Sikkim. There were no recent records of Dholes from Manipur and Tripura. A total of 5033 camera trap-days in Dampa Tiger Reserve generated 500 photoencounters of Dholes, comprising 92 detections (one per 24 hour duration) across 33 sites. 

Singh et al. found photo-capture frequencies of key prey species: Sambar (236), Muntjac (145), Wild Pig (92); to be positive influences, as were the distance to reserve boundary, and photo-capture frequencies of Forest Department personnel, while photo-capture frequencies of other humans were  negative influences on site-use by Dholes.

There are records of Dholes across several areas of northeast India, including in unprotected areas. Previous global assessments indicated that the species faced near or complete local extirpation to the south of the River Brahmaputra, something refuted by Sigh et al.'s findings from Dampa Tiger Reserve. Corroborating current knowledge from other landscapes, showed a positive relationship between Dhole site-use and Sambar presence. Across their extant distribution, the range of Dholes overlaps with that of Tigers and Leopards, Panthera pardus. Wildlife managers in this region and elsewhere subscribe to unsubstantiated notions that dhole presence impedes colonisation by Tigers, and consequently treat Dholes as a problem species. On the contrary, Tigers, Leopards and Dholes can co-exist provided protected areas support adequate densities of medium- to large-sized prey species.

Dampa Tiger Reserve is an important refuge for Dholes in northeast India. It supports large tracts of inviolate protected spaces, and habitat connectivity with forested landscapes of the Chittagong Hill Tract region to the west, Mamit Forest Division to the north and Thorangtlang Wildlife Sanctuary to the south. Singh et al's camera-trap data indicate the presence of a guild of large herbivores in the Reserve, with at least five prey species of medium and large ungulate herbivores, facilitating the long-term persistence of dholes there. The findings re-emphasise the importance of protected areas, which can serve as source sites for sustaining Dhole populations across the region.

In areas with low prey densities, carnivores may have significant dependence on livestock, and are consequently stigmatised. There is a strong negative relationship between Dholes and livestock owners in Arunachal Pradesh and other locations in the region. Given that Dholes also occur outside protected areas in this region, they are potentially vulnerable to retributory killing. Negative interactions between people and Dholes necessitate interventions to reduce poaching and facilitate recovery of prey, especially for species such as Sambar that are impacted by low recovery rates following prolonged poaching. Singh et al.'s findings need to be augmented with a systematic survey across the locations they identified, specifically in the states of Mizoram and Nagaland, to facilitate a pan-northeast India strategy for Dhole conservation.

See also...

https://sciencythoughts.blogspot.com/2019/08/leopard-attack-thwarted-by-dog-in.htmlhttps://sciencythoughts.blogspot.com/2019/08/camper-attacked-by-wolf-in-banff.html
https://sciencythoughts.blogspot.com/2018/07/worker-at-western-australian-gold-mine.htmlhttps://sciencythoughts.blogspot.com/2016/08/cynarctus-wangi-new-species-of.html
https://sciencythoughts.blogspot.com/2016/07/photogrammetry-as-tool-in-morphometric.htmlhttps://sciencythoughts.blogspot.com/2016/04/lycaon-pictus-african-hunting-dogs.html
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