The Silent Valley National Park, one of the few remaining rainforests in the country, gets one of the highest, or even the highest, average annual rainfall in the Western Ghats, show the data of the past 10 years.
The highest average annual rainfall received in the valley was 8,361.9 mm in 2001. In 2000, the figure was 7,788.8 mm; in 2002, 4,262.5 mm; in 2003, 3,499.65 mm; in 2004, 6,521.27 mm, in 2005, 6,919.38 mm; in 2006, 6,845.05 mm; in 2007, 6,009.35 mm; and in 2008, 4386.5 mm. The figure till October this year is 5,477.4 mm.
The average annual rainfall of the Western Ghats ranges from 6,000 mm at the crest of the ghats to as low as 600 mm in the valley portion, says Regional Analysis of Rainfall Extremes of Western Ghats, a study conducted by B. Venkatesh and M. Bonne of the National Institute of Hydrology, Karnataka.
Thus, the Silent Valley gets the highest average annual rainfall in the Western Ghats.
The area also accounts for one of the highest rainfalls in India. Mawsynram in the Khasi Hills of the Himalayas in Meghalaya is known as the world’s wettest place, with an annual rainfall of 11,873 mm, says L. Namasivayam, environmentalist. Cherrapunji held the record earlier.
S. Sivadas, Wildlife Warden of the Silent Valley National Park, told The Hindu here on Thursday that the Walakkad and the Poochippara areas had been recording the highest rainfall in the valley since 2000.
Up to October this year, Poochippara received a rainfall of 7,639 mm and Walakkad, 5,931 mm. But Walakkad had received more rain than Poochippara in most of these nine years.
In 2006, Walakkad received the highest ever rainfall of 9,569.6 mm. In 2000, the figure was 7,788 mm; 2001, 8,351.9 mm; 2004, 8465.3 mm; and 2005, 9,347.8.
In 2007, Poochippara received the highest ever rainfall of 8,093.7 mm. In 2004, the area received 7,020.1 mm; in 2005, 6,945.6 mm; and 2006, 7650.8 mm.
The Sairandhri area, where a dam was proposed in the 1970s for the aborted Silent Valley hydroelectric project, also gets good rain.
In 2004, the area received 5,005.2 mm of rainfall, in 2005, 5,669 mm; in 2008, 4,507.9 mm; and up to October this year, 4,214.7 mm.
The Neelikkal area received an annual rainfall of 5,715.1 mm in 2005; 5,441 mm in 2006; 5,842.8 mm in 2007; and 3,737.9 mm in 2008.
Saby Varghese, Range Officer of the park, said that Silent Valley got continuous rain for six to seven months a year. In the remaining months, mist shrouded the valley, which was estimated to be yielding 15 per cent of
the water generated in the rainforest, with both the north-east and the south-west monsoons blessing the valley.