Today's Headlines - 12 August 2023
‘Sponge cities’ not stopped the floods
GS Paper - 1 (Geography)
China has been hit by devastating floods, inundating cities and causing deaths and infrastructural damage, as well as raising questions about the effectiveness of its 2015 “sponge city” initiative aimed at reducing urban flood risks. The initiative was launched to boost flood resilience in major cities and make better use of rainwater through architectural, engineering and infrastructural tweaks.
Why was the initiative launched?
China has long sought to improve the way it handles extreme weather, and make highly populated cities less vulnerable to flooding and drought.
The “sponge city” initiative was designed to make greater use of lower-impact “nature-based solutions” to better distribute water and improve drainage and storage.
Those solutions included the use of permeable asphalt, the construction of new canals and ponds and also the restoration of wetlands, which would not only ease waterlogging, but also improve the urban environment.
Breakneck urbanisation has encased vast stretches of land in impermeable concrete, often along banks of major rivers that traditionally served as flood plains. With wetlands paved over and nowhere for surplus water to settle, waterlogging and flooding was commonplace.
What has been done so far?
Studies show that many of the local pilot initiatives launched so far have had a positive effect, with low-impact projects like green roofs and rain gardens reducing run-offs.
But implementation has so far been patchy. A total of 30 pilot sponge cities were selected in 2015 and 2016.
By last year, only 64 of China’s 654 cities had produced legislation to implement sponge city guidelines, researchers said in January.
The researchers said the government had so far paid “minimum attention” to sponge city construction, and called for national legislation to be drawn up as soon as possible.
What are the limitations of sponge cities?
Even if sponge city measures had been implemented in full, they would have been unable to prevent this year’s disasters.
Zhengzhou in Henan province was one of the most enthusiastic pioneers of sponge city construction, allocating nearly 60 billion yuan to the programme from 2016 to 2021. But it was unable to deal with its heaviest rainfall in history in 2021.
Experts believe sponge city infrastructure can only handle no more than 200 millimetres (7.9 inches) of rain per day.
At the height of the rainstorms that lashed Beijing at the end of July, rainfall at one station reached 745 millimetres over three and a half days. In July 2021, Zhengzhou saw rainfall in excess of 200 mm in just one hour.
Authorities are also playing catch-up to climate change. This year’s heavy rain hit cities in the normally arid north, where sponge city development is less advanced.
#upsc #news #headline #sponge #floods #geography #china #weather #launched #damage #city #rainwater #wetlands #urbanisation #restoration #canals #ponds #limitations #legislation #disasters #zhengzhou #henan #development #climatechange #rainstorms #rainfall
‘Sponge cities’ not stopped the floods
GS Paper - 1 (Geography)
China has been hit by devastating floods, inundating cities and causing deaths and infrastructural damage, as well as raising questions about the effectiveness of its 2015 “sponge city” initiative aimed at reducing urban flood risks. The initiative was launched to boost flood resilience in major cities and make better use of rainwater through architectural, engineering and infrastructural tweaks.
Why was the initiative launched?
China has long sought to improve the way it handles extreme weather, and make highly populated cities less vulnerable to flooding and drought.
The “sponge city” initiative was designed to make greater use of lower-impact “nature-based solutions” to better distribute water and improve drainage and storage.
Those solutions included the use of permeable asphalt, the construction of new canals and ponds and also the restoration of wetlands, which would not only ease waterlogging, but also improve the urban environment.
Breakneck urbanisation has encased vast stretches of land in impermeable concrete, often along banks of major rivers that traditionally served as flood plains. With wetlands paved over and nowhere for surplus water to settle, waterlogging and flooding was commonplace.
What has been done so far?
Studies show that many of the local pilot initiatives launched so far have had a positive effect, with low-impact projects like green roofs and rain gardens reducing run-offs.
But implementation has so far been patchy. A total of 30 pilot sponge cities were selected in 2015 and 2016.
By last year, only 64 of China’s 654 cities had produced legislation to implement sponge city guidelines, researchers said in January.
The researchers said the government had so far paid “minimum attention” to sponge city construction, and called for national legislation to be drawn up as soon as possible.
What are the limitations of sponge cities?
Even if sponge city measures had been implemented in full, they would have been unable to prevent this year’s disasters.
Zhengzhou in Henan province was one of the most enthusiastic pioneers of sponge city construction, allocating nearly 60 billion yuan to the programme from 2016 to 2021. But it was unable to deal with its heaviest rainfall in history in 2021.
Experts believe sponge city infrastructure can only handle no more than 200 millimetres (7.9 inches) of rain per day.
At the height of the rainstorms that lashed Beijing at the end of July, rainfall at one station reached 745 millimetres over three and a half days. In July 2021, Zhengzhou saw rainfall in excess of 200 mm in just one hour.
Authorities are also playing catch-up to climate change. This year’s heavy rain hit cities in the normally arid north, where sponge city development is less advanced.
#upsc #news #headline #sponge #floods #geography #china #weather #launched #damage #city #rainwater #wetlands #urbanisation #restoration #canals #ponds #limitations #legislation #disasters #zhengzhou #henan #development #climatechange #rainstorms #rainfall
Today's Headlines - 16 August 2023
Isro’s space probe to study the Sun
GS Paper - 3 (Space Technology)
The Indian Space Research Organisation (Isro) released images of the Aditya-L1 mission — the space agency’s first attempt to study the Sun. The satellite has reached the Satish Dhawan Space Center (SDSC) in Sriharikota, Andhra Pradesh, for its integration with the launch vehicle, PSLV.
What is the Aditya-L1 mission?
The Aditya-L1 will observe the Sun from a close distance, and try to obtain information about its atmosphere and magnetic field.
It’s equipped with seven payloads (instruments) on board to study the Sun’s corona, solar emissions, solar winds and flares, and Coronal Mass Ejections (CMEs), and will carry out round-the-clock imaging of the Sun.
Why is studying the Sun important?
Every planet, including Earth and the exoplanets beyond the Solar System, evolves — and this evolution is governed by its parent star.
The solar weather and environment affect the weather of the entire system. Variations in this weather can change the orbits of satellites or shorten their lives, interfere with or damage onboard electronics, and cause power blackouts and other disturbances on Earth. Knowledge of solar events is key to understanding space weather.
To learn about and track Earth-directed storms, and to predict their impact, continuous solar observations are needed.
Every storm that emerges from the Sun and heads towards Earth passes through L1, and a satellite placed in the halo orbit around L1 of the Sun-Earth system has the major advantage of continuously viewing the Sun without any occultation/eclipses.
L1 refers to Lagrangian/Lagrange Point 1, one of five points in the orbital plane of the Earth-Sun system. Lagrange Points, named after Italian-French mathematician Josephy-Louis Lagrange, are positions in space where the gravitational forces of a two-body system (like the Sun and the Earth) produce enhanced regions of attraction and repulsion.
These can be used by spacecraft to reduce fuel consumption needed to remain in position. The L1 point is home to the Solar and Heliospheric Observatory Satellite (SOHO), an international collaboration project of NASA and the European Space Agency (ESA).
The L1 point is about 1.5 million km from Earth, or about one-hundredth of the way to the Sun. Aditya L1 will perform continuous observations looking directly at the Sun.
NASA’s Parker Solar Probe, launched in 2018, has already gone far closer — but it will be looking away from the Sun.
The earlier Helios 2 solar probe, a joint venture between NASA and the space agency of erstwhile West Germany, went within 43 million km of the Sun’s surface in 1976.
#upsc #news #headline #ISRO #study #sun #space #technology #india #space #research #technology #aditya #mission #SDSC #satishdhawanspacecenter #srihorikota #andhrapradesh #PSLV #distance #magnetic #corona #solar #planet #weather #earth #repulsion #gravitational #forces #fuel #SOHO #NASA #germany #surface
Isro’s space probe to study the Sun
GS Paper - 3 (Space Technology)
The Indian Space Research Organisation (Isro) released images of the Aditya-L1 mission — the space agency’s first attempt to study the Sun. The satellite has reached the Satish Dhawan Space Center (SDSC) in Sriharikota, Andhra Pradesh, for its integration with the launch vehicle, PSLV.
What is the Aditya-L1 mission?
The Aditya-L1 will observe the Sun from a close distance, and try to obtain information about its atmosphere and magnetic field.
It’s equipped with seven payloads (instruments) on board to study the Sun’s corona, solar emissions, solar winds and flares, and Coronal Mass Ejections (CMEs), and will carry out round-the-clock imaging of the Sun.
Why is studying the Sun important?
Every planet, including Earth and the exoplanets beyond the Solar System, evolves — and this evolution is governed by its parent star.
The solar weather and environment affect the weather of the entire system. Variations in this weather can change the orbits of satellites or shorten their lives, interfere with or damage onboard electronics, and cause power blackouts and other disturbances on Earth. Knowledge of solar events is key to understanding space weather.
To learn about and track Earth-directed storms, and to predict their impact, continuous solar observations are needed.
Every storm that emerges from the Sun and heads towards Earth passes through L1, and a satellite placed in the halo orbit around L1 of the Sun-Earth system has the major advantage of continuously viewing the Sun without any occultation/eclipses.
L1 refers to Lagrangian/Lagrange Point 1, one of five points in the orbital plane of the Earth-Sun system. Lagrange Points, named after Italian-French mathematician Josephy-Louis Lagrange, are positions in space where the gravitational forces of a two-body system (like the Sun and the Earth) produce enhanced regions of attraction and repulsion.
These can be used by spacecraft to reduce fuel consumption needed to remain in position. The L1 point is home to the Solar and Heliospheric Observatory Satellite (SOHO), an international collaboration project of NASA and the European Space Agency (ESA).
The L1 point is about 1.5 million km from Earth, or about one-hundredth of the way to the Sun. Aditya L1 will perform continuous observations looking directly at the Sun.
NASA’s Parker Solar Probe, launched in 2018, has already gone far closer — but it will be looking away from the Sun.
The earlier Helios 2 solar probe, a joint venture between NASA and the space agency of erstwhile West Germany, went within 43 million km of the Sun’s surface in 1976.
#upsc #news #headline #ISRO #study #sun #space #technology #india #space #research #technology #aditya #mission #SDSC #satishdhawanspacecenter #srihorikota #andhrapradesh #PSLV #distance #magnetic #corona #solar #planet #weather #earth #repulsion #gravitational #forces #fuel #SOHO #NASA #germany #surface