Type: Prelims Only

Why in the News?

The Karnataka government has formed an expert committee, headed by Niranjan, Chief Environment Officer of Karnataka State Pollution Control Board, to study the pollution level in the Cauvery.

About Cauvery River

• The Cauvery River, also spelled as ‘Kaveri’ and known as ‘Ponni’ in Tamil, originates from Talakaveri in the Brahmagiri range located in Karnataka’s Kodagu district.
• It spans approximately 800 km, traversing through the states of Karnataka and Tamil Nadu, until it eventually reaches the Bay of Bengal.
• The river’s catchment area covers regions in Tamil Nadu, Kerala, Karnataka, and the Union Territory of Pondicherry.
• Key tributaries that join the Cauvery include Harangi, Hemavati, Kabini, Suvarnavathi, and Bhavani.
• It remains perennial due to its dual reliance on both advancing and retreating monsoons for rainfall.
• Protected areas in its basin: Cauvery WLS,  Biligirirangan Hills WLS,  Pushpagiri WLS,  Muthathi WLS,  Ranganathittu Bird Sanctuary,  Bhimeshwari WLS, Nagarhole NP; Bandipur NP.

Challenges associated with the Cauvery River:

• Direct discharge of untreated sewage and domestic waste from towns and cities along the Cauvery contaminates the water, leading to high bacterial loads and nutrient pollution.
• Industries along the Cauvery, including textiles, dyeing, pharmaceuticals, and others, discharge effluents directly into the river.
• Pesticides, herbicides, and fertilizers used in agricultural fields adjacent to the river are washed into the Cauvery during rain and irrigation.
• Unregulated sand mining and dredging activities disrupt riverbeds and banks, altering natural flow patterns and habitat structures.
• Introduction of non-native species like tilapia and African catfish, initially for aquaculture, has led to their proliferation in the Cauvery.

Why in the News?

The Delhi High Court is set to physically inspect the Central and Southern parts of Delhi Ridge to assess the extent of afforestation and cutting of trees in the area.

About Delhi Ridge

• Delhi Ridge is located in the National Capital Territory of Delhi, extending as a northern extension of the ancient Aravalli Range.

• • Composed primarily of quartzite rocks, it spans approximately 35 kilometres from Tughlaqabad in the southeast to Wazirabad in the north along the Yamuna River.

• Ecological Significance:

• • It acts as the “green lungs” of Delhi, providing crucial ecological services such as carbon sequestration and habitat for wildlife.
  • It protects Delhi from the hot desert winds originating from Rajasthan to the west.
  • It supports diverse flora and fauna, making Delhi one of the world’s most bird-rich capital cities.
  • Efforts are ongoing to maintain biodiversity through biodiversity parks and wildlife sanctuaries like the Northern Ridge Biodiversity Park and Asola Bhatti Wildlife Sanctuary.

Geographical Features

• The ridge is believed to be over 1.5 billion years old, making it an ancient geological formation compared to the Himalayas (50 million years old).
• It functions as a watershed, dividing the Indus Plain to the west from the Gangetic Plain to the east within the Indo-Gangetic Plain.

Administrative Divisions:

• Divided into four main zones: Northern, Central, South-Central, and Southern Ridge.
• Each zone has distinct characteristics and faces varying degrees of urban encroachment and conservation efforts.