What and where

Theri Kaadu (“red sand forest”) is a striking belt of aeolian red-sand dunes in Thoothukudi district, along the Gulf of Mannar coast. The sands owe their colour to iron-oxide–rich grains (including garnet) that were weathered from inland rocks, carried by rivers to paleo-beaches, and then blown landward by seasonal winds to form dunes.

Why it matters

• A rare coastal desert–scrub mosaic in peninsular India, with palmyra groves, hardy grasses (e.g., Spinifex), larks, coursers, foxes, reptiles and pollinators.
• Natural sand reservoirs that buffer storm surges and store freshwater lenses.
• Cultural landscape: palmyra-based livelihoods and small pastoral systems.

Pressures on the dunes

• Unregulated sand and mineral mining, off-road driving, fencing and construction.
• Invasive Prosopis choking native scrub; casuarina blocks altering dune movement.
• Groundwater extraction and poorly managed tourism waste.

Policy frame and fixes

• Governed by the Biological Diversity Act, 2002, Coastal Regulation norms along adjoining shorelines, and district sand-mining rules.
• Practical steps: map and notify dune conservation zones; restore with native grasses and palmyra; remove invasives; regulate vehicle access; community eco-guiding; make resorts and roads set-back and low-impact; dovetail with Gulf of Mannar conservation and Swachh Bharat Mission–Urban waste control.

Theri Kaadu at a glance

Key terms:

Aeolian dunes, paleo-beach, freshwater lens, invasive species, set-back line.

Exam hook

Use Theri Kaadu to illustrate coastal geomorphology, ecosystem services, and community-led restoration in short geography answers.

UPSC Prelims question

Theri Kaadu’s red dunes primarily result from:

1. Volcanic ash
2. Iron-oxide–rich beach sands reworked by wind
3. Laterite crusts
4. River flood silts

Answer: (b)

One-line wrap

Protect the red dunes, restore natives, and keep machines off—Theri Kaadu is a living shield for Tamil Nadu’s coast.