Post

How to get URL link on X (Twitter) App

On the Twitter thread, click on or icon on the bottom
Click again on or Share Via icon
Click on Copy Link to Tweet
Paste it above and click "Unroll Thread"!
More info at Twitter Help

Raj Bhagat P #Mapper4Life

@rajbhagatt

Oct 16, 2021 • 8 tweets • 3 min read • Read on X

Scrolly

#Thread - #Bengaluru Airport:
What exactly happened in Bengaluru airport that led to the flooding/stagnation a few days before?
My version:

Before the airport, area (marked in white) was in a ridge between 2 valleys, had cropland, quarries, a minor valey, open scrubland
1/n

Even after the completion of phase I which was the runway in the northern side and the terminal, the minor valley was not affected significantly as it was all limited to the northern side. One quarry site also remained holding stagnant water.
2/n

This map gives you the terrain of the airport area and one can easily notice the ridge on which it was built. Water was supposed to drain into the main valleys through the minor valley.
Approximate water flow directions are marked for better understanding of terrain
3/n

As Airport(new runway) is being expanded to the south (marked in red), minor valleys & paths for water to drain were being blocked & heavily concretized
I dont know if final design incorporates / has enuf drains, but during construction phase it didn't have provision for flow

Beyond the construction phase also, there could be some issues as the old lake which existed in the middle of the airport are is being concrete lined & will not be helpful in handling flood situations in future.

In conclusion:
The rainfall in airport was heavy but it is not reason behind the flood scenes in the airport. Over concretization which reduces percolation of water, blockage of natural drains caused it

Respect the valley! It could continue if necessary paths are not provided

https://twitter.com/ChristinMP_TOI/status/1447628562937237507?s=20

In reference:

https://twitter.com/ChristinMP_TOI/status/1447628562937237507?s=20

Sorry if this was too late. Didnt work for few days because of vaccine :(

• • •

Missing some Tweet in this thread? You can try to force a refresh

This Thread may be Removed Anytime!

Twitter may remove this content at anytime! Save it as PDF for later use!

More from @rajbhagatt

Raj Bhagat P #Mapper4Life

@rajbhagatt

Feb 24

#Thread

What geographical features can we observe from the sky while on a flight from Thiruvananthapuram to Chennai? (approx path in map)

Equip yourselves with apps for more information from GPS.. Also notice the weaker signals from the satellites on the right side because I am sitting on the left side windows. Also preload maps in google maps so that you can identify features

In Thiruvananthapuram, we can notice a large sediment plume on the coast. This is largely around the Trivandrum Titanium Ltd

Read 27 tweets

Raj Bhagat P #Mapper4Life

@rajbhagatt

Jan 11

#Thread on #Tiruchendur erosion

Of recently, we might have come across the news that a lot of erosion has happened right next to the famous Murugan temple in Tiruchendur. In this thread of maps, I would discuss the causes and possible solutions

To provide context, this photo shows the area near the next to the temple which has eroded significantly and the beach used to extend further

#Satellite image shows the Tiruchendur coastline from last year in the month of January. The beach marked to the south of Murugan temple is the one facing erosion.

Read 20 tweets

Raj Bhagat P #Mapper4Life

@rajbhagatt

Oct 15, 2024

#Thread without Maps on #floods
If physical problems and solutions are known theoretically, then why are we not able to solve flooding situations in our cities whether it is Chennai or Bengaluru or Delhi?

There are 4 layers to the prob - Technical, Planning, Finance, Governance

Technical:
Our cities are not designed to take the rainfall that they face. The storm water drains are inadequate and the network is disconnected. Most of the drains are built in adhoc manner (if they are built). But why does this happen?

Cities don't have a storm water management plan. A plan that can comprehensively provide the technical details on the storm water network based on run off calculations, land etc is absent in most cases or poorly prepared in the remaining.
Why hasnt been it prepared?

Read 16 tweets

Raj Bhagat P #Mapper4Life

@rajbhagatt

Oct 2, 2024

#Thread on Vijaywada floods
In September this year, after a spell of heavy rain, Vijayawada was affected by severe floods. This thread would explore the geographical reasons behind it and what can be done from here.
(1/n)

2. #Map shows the profile of four major rivers in India. Vijayawada is in the lower section of Krishna river and close to where the river exits the plateau and enters the deltaic flat plains.

3. There are 3 basins in the region whose histories are intertwined. Vijayawada city is sitting on the Krishna and Kolleru systems. Though the Krishna river was also flooding, the city was actually flooded by Budameru Vagu, a seasonal river which is part of the Kolleru system

Read 26 tweets

Raj Bhagat P #Mapper4Life

@rajbhagatt

Aug 24, 2024

Google maps shows my GPS position to be well inside the sea in #Chennai Marina beach. But I was away from it. Why?

#Thread continuation of my previous one on Chennai #Marina beach
1/n

In the previous thread, I had explained how Marina beach is growing (sea becoming more and more land). Because of the longshore drift, lots of sand hence gets settled in the mouths of Cooum River.

To prevent further siltation in the mouth of the river, the government had built Groynes so that the capacity of the river doesn't get reduced.

Read 15 tweets

Raj Bhagat P #Mapper4Life

@rajbhagatt

Aug 16, 2024

#Thread
#Marina beach is one of the most iconic destinations in Chennai and one of the most visited beaches in the world. However the beach as we see today didn't exist a century ago.

This thread explains the formation of #Chennai's Marina beach
1/n

This map below shows the approximate original coastline of Chennai during British era. It was much closer to the Kamarajar road. A promenade was developed during the british era and that is when it got the name, "Marina". However the big sandy expanse itself didnt exist
2/n

Seas are very dynamic in nature. Whenever the waves hit the beach which is called as "swash", they bring in sand and when the water goes back ("backwash"), it removes the sand. This balance is critical for beach existence.