BharatSangraha

Patkai & Tirap Belt · Eastern Himalaya & Brahmaputra Belt

Terrain and eco-zones

Wet and warm at the base, with 2,500–4,000 mm falling over a long season from March to October rather than in a single burst. The Namdapha lowland is tropical wet evergreen forest with no dry month worth the name; the Tirap ridges are subtropical and cooler; and the Dapha Bum ridge behind the park holds permanent snow. Winter is dry, misty in the mornings and the only reliable travelling season.

Landforms

The Patkai range — the northern end of the Indo-Burman arc, where the mountain grain turns south-westPangsau Pass at 1,136 m, the lowest practicable crossing in the eastern hillsDapha Bum at 4,571 m, giving Namdapha an altitude span of more than four kilometresNamchik–Namphuk Tertiary coal measures, outcropping close enough to the surface to be worked openlyRidge-crest village siting on the Tirap hills, with fields on the slopes below and water carried up

Rivers and waters

Noa-Dihing — the river of Namdapha, running west out of the park past Deban and MiaoBuri Dihing — the main drainage of the foothill belt, flowing into the BrahmaputraTirap — the river the district is named for, rising on the ridges above KhonsaNamchik and Namphuk — small rivers giving their names to the coalfield they cut throughTissa and Dikrong tributaries feeding the Buri Dihing off the western slope

Through the year

SeasonMonthsTypicalWhat it is like
Dry winterNovember–February8–24 °CThe travelling and festival season. Chalo Loku falls at the start of it, the Pangsau Pass festival in January, Oriah in February at Longding. Namdapha is walkable and the leeches are gone.
Pre-monsoonMarch–May18–32 °CJhum plots are burned, Moh-Mol and Sangken fall in April, and the first heavy showers arrive well before the monsoon proper.
RainsJune–September23–33 °CContinuous. The Noa-Dihing becomes uncrossable, the road past Deban closes, and the Stilwell alignment beyond Nampong turns to the mud that gave the pass its wartime nickname.
HarvestOctober20–30 °CRice comes in, pigs are fattened for Loku, and the year's rice beer is brewed.

Best time to visitNovember to March. January if the point is the Pangsau Pass Winter Festival at Nampong; mid-February for Oriah at Longding; late October or November for Chalo Loku in the Nocte villages. Namdapha is best from November to March, and needs several days to be worth entering at all.

The climate, landforms, rivers and seasons of Patkai & Tirap Belt, and the best time of year to visit. (4)