North India Deluge 2023: Yamuna crosses warning mark in Delhi amid heavy rain in upper catchment

Subject: Geography

Section: Physical geography

Context:

The Yamuna River in Delhi crossed the warning mark in Delhi on July 10, 2023, as its level reached 204.63 metres.

Why river Yamuna crossed the warning mark in Delhi?

Heavy rainfall in the upper catchment of the Yamuna River.
Release of more water into the Yamuna from the Hathnikund barrage upstream in Haryana.

The water level in Yamuna River:

The level of 204.63 metres was recorded at the Old Railway Bridge in Delhi.
The warning level is 204.5 metres.
The evacuation of people from low-lying areas around the Yamuna will be initiated once the river touches the 206-metre mark.
The danger level is 205.5 metres as per the Central Water Commission.
The Delhi government has set up 16 control rooms that include a central control room.
Its aim will be to monitor the flood-prone areas and the water level of the Yamuna.

Disaster Preparedness Plan:

A comprehensive flood management plan is needed to include Disaster preparedness.
This may require strengthening of the following:
- Flood Hotspot Mapping at a local and regional scale.
- Management and regulation of riparian zones to prevent spilling and erosion.
- River flood modelling to prepare for incidences like reservoir breaches and emergency water release from dams.
- Advanced techniques such as mapping based on satellite imagery and Geographic Information Systems will help in the development of flood early warning systems.

Yamuna river:

The Yamuna originates at the Yamunotri glacier (near Banderpoonch peaks) in Uttarakhand.
It flows in a southerly direction through the Himalayan foothills and after exiting Uttarakhand, enters the Indo-Gangetic plain, along the border between Uttar Pradesh and Haryana states. The Eastern and Western Yamuna canals are fed from the river at that point.
It then passes Delhi, where it feeds the Agra Canal.
South of Delhi, and within Uttar Pradesh, it turns south-eastward near Mathura and passes Agra, Firozabad, and Etawah.
Below Etawah, it receives a number of southern tributaries, the largest of which are the Chambal, the Sindh, the Betwa and the Ken.
The Yamuna joins the Ganga near Prayagraj in Uttar Pradesh, after a course of about 855 miles (1,376 km).