A small river/stream existed near Angul #Odisha. The land around it was allotted to JSPL for development...
The company thought the course of the river was too disturbing and decided to change the course of the river.
However there were other smaller streams that were draining into it (obviously) & since the new course didnt account it, they started stagnating (marked in white circle)
No matter how much they filled the land, it continued stagnating and creating issues for authorities and farmers nearby.
Issue was not just that an environmentally problematic project was undertaken, they did it without taking permissions too!
NGT has now slapped a small fine (2 Crores) for changing the course without permission.
A company with an annual revenue of approx 34,000 crore rupees has been asked to pay a fine of 2 crore rupees for permanently damaging and modifying the course of a river without permission.. Remember this 😇
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Short thread of satellite images
Story of a navigational canal that was built with ~12 crore rupees tax payer money in #Ganga riverbed in #Varanasi Uttar Pradesh.
Before the construction of the canal, this was the river Ganga 1/n
In March 2021, the construction started in the river bed where we can see the machines in action. The canal was supposed to be built parallel to the main river but within the bed.
2/n
By May, the construction had progressed and we can see the canal taking a shape (highlighted in white)
#Thread
Many parts of #Chennai have been inundated after heavy rains (22 cm) last night. The city like all other in India faces a wide range of issues and it is UNLIKELY to solve any of the urban flooding related problems that it faces within the next 10 years.
Here's why 1/n
Chennai Metropolitan region (in particular the city corporation) is relatively flat terrain and is very close to sea level. The agricultural activity in the region had prompted construction of thousands of lakes which were shallow and large in area
Over the years, the city expanded and in many places (like South Chennai marked here) expanded in low lying areas (and wetlands) which are extremely close to sea level and water would tend to stagnate
Map shows builtup expansion
Thread #Haldwani case:
After extreme rainfall in #Uttarakhand, a bridge failed across Gaula river near Haldwani
Rain wasn't sole cause, it just brought d collapse a bit earlier
Himalayan rivers exit mountains & enter plains with great intensity & it is a critical zone
It is in this critical section is Haldwani where the Gaula river exits the himalayas and enters plains. Rivers bring huge amount of sediments with them to settle as well as they have high intensity flows during monsoon to erode
Visual shows the location of the bridge that failed
Failure of a bridge is nothing new in the region. The previous bridge across the Gaula river (shown with old satellite image below) had collapsed in 2008 after floods
#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
I would be posting some #maps about the river with finer details in this thread in coming days! Bookmark..
FAQ
Data: SRTM
Software: QGIS
One of the biggest engineering works in Kaveri river is the Kallanai / Grand Anicut system. It was not constructed in 1 step & most of the structure that we see were erected during British era
Annotated drone image from @vikatan. The subsequent tweets deal with history of dam
The thread shows the recent history and transformations it went through over time.
#Map shows the location of lake with an approximate boundary of the plot.
The waterbody in Lakkasandra might have lost its original applications many decades ago and hence revenue maps (given on the left) shows it as a government land but not specifically as a waterbody. Google Maps however shows the waterbody as it was detected in the early 2000s
But the lake seems to have water in many satellite images from 1970s, 1980s, and 1990s. It has attributes similar to any seasonal rainfed waterbody in the region