North India Deluge 2023

North India Deluge 2023

Subject: Geography

Section: Physical geography 

Context:

• Ladakh, a cold desert, received over 10,000% of its normal rain on July 8-9.
• The entire state of Himachal Pradesh received 1,193 per cent excess rainfall on July 9, 2023. The district of Lahaul-Spiti received 3,640 per cent excess rainfall.

Details:

• The occurrence was part of the extreme rainfall events all over north and northwest India due to a rare interaction of a western disturbance with the monsoon system, currently in an active mode over the country.
• There are also small landslides around Leh City.
• An extremely unlikely cloudburst event occurred in the Ladakh region in August 2010 which was attributed to global warming.
• Socio-economic impact of increased precipitation:
  • In recent years, more precipitation is happening in the cold desert region in the form of rain rather than snow.
  • This has created problems for the people of Ladakh who now have to adapt to the rains.
  • More houses are being built with cement which creates frigid conditions inside the houses, making it difficult to warm up the interiors.
  • Earlier people of this region used sun-baked mud bricks for the construction of houses which used to keep the interiors warm.
• Lahaul-Spiti is one of three cold deserts in India.
  • Losar village in the Lahul-Spiti district received snowfall for the first time in July.
  • This area is very sensitive to excessive rainfall. Situated at an average of 4,270 metres above sea level, this district receives snowfall for about four months in winter.
  • Due to snow, the vegetation in the district, especially in the Spiti area, is negligible and this entire area is known as a cold desert.
  • Since a large part of the district is nestled in the debris of melted glaciers (moraines), heavy rains become a nuisance for the region.
  • May-August is the only cropping season in this district. After the snow melts in March-April, pea sowing begins in the higher reaches of Spiti. They are harvested in September-October.
  • Crops require average rainfall in June for post-sowing irrigation.

What are Cold deserts?

• A cold desert is an arid habitat with an annual rainfall of less than 25 cm. They have a temperate climate with scorching summers and chilly winters because they are situated at a high latitude in the interior of the continent.
• Here weather and soil are not suitable for plant growth. Hence land is bereft of vegetation except for isolated, scattered and overgrazed herbaceous shrubs.
• The grazing period is less than 3-4 months and it is mainly during the hot season only.
• It generally occurs in Ladakh, Leh and Kargil areas of Kashmir and the Spiti valley of Himachal Pradesh.

Classifications

• Dry temperate zone: Vegetation includes – Betula utilis, Salix spp, Juniperus recurva
• Alpine Zone: Vegetation includes – Junipers, Birch, and Rhododendron with grass
• Perpetual snow zone: No vegetation due to permanently frozen soil

Global distribution of cold desert:

• North America – Great Basin
• South America – Atacama Desert, Patagonian desert
• Eurasia – Iranian desert, Gobi desert, Turkestan
• Africa – Namib Desert

Characteristics of Cold Deserts:

• Most of the time, the temperature is below zero degrees Celsius, which prevents plants from absorbing water.
• Due to the extremely dry atmosphere and low mean annual rainfall (less than 400 mm), the area has a desert-like characteristic.
• Snowfall is heavy and occurs between late November and early April.
• Wind erosion is more common.
• Soil is sandy to sandy loam and neutral to sight alkaline in nature.
• Soil has poor organic matter content and low water retention capacity.
• The growing period is narrow which is mostly during the summer season.