Monday, July 31, 2023

The deluge of Delhi (08Jul- 15Jul2023): some data, maps and images

Meteorological conditions

The meteorological conditions which caused the flooding of Delhi in 2023 between 08July till approximately 15July2023 have already been described in the previous blog - the same conditions which caused landslides and destruction in Himachal Pradesh resulted in parts of Delhi getting flooded by the Yamuna river.

As a matter of fact, large parts of Himachal and the foothills of Haryana and Punjab form the watershed area for the Yamuna river and much of the storm water from these areas finally drains into the Yamuna (see map below).

Rainfall from these catchment areas which eventually led to the flooding is as follows:
The average monthly rainfall for Delhi with other associated rainfall data is given below:
The actual rainfall
CM of Delhi, Arvind Kejriwal made a press statement saying that on 08/09Jul2023, Delhi had received 153mm of rain and the city's systems were "not designed to take such unprecedented rain", due to which major roads were submerged, traffic disrupted, and homes and businesses inundated.
According to officials, Delhi's outdated drainage system can handle only up to 50 mm of rainfall in 24 hours.

However, what became clear was it was not only climate change or the heavy rainfall which had caused the flooding in Delhi. It was also the release of Yamuna water from Hathnikund barrage in Haryana which caused the inordinate amounts of water to reach Delhi
Also involved was the water management of Yamuna river in the 22km that the river flowed thru Delhi. The 3 barrages which managed this is shown below
Flooded areas and satellite images
The areas which were flooded in early July 2023 were those in the vicinity of the Yamuna river in NE Delhi and also some areas for whom it was a grim first time - parts of Ring Road, Mathura road etc.
Planetscope Videos
ISBT, Kashmiri Gate, Delhi Jal Board Area
Yamuna Biodiversity Park Area

We will keep updating these inputs in the future
Update on 09Aug2023

Praful Rao
Kalimpong district
Darjeeling-Sikkim Himalaya

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