Sediment Transfer through the Fluvial System (Proceedings of a symposium held in Moscow, August 2004). IAHS Publ. 288, 2004, 488–493

1 CNRM, VPO Tarore 181133, District Jammu, Jammu & Kashmir, India

2 S. K. University of Agricultural Sciences & Technology, Jammu & Kashmir, India

Abstract The northeastern region of India is predominantly hilly with an average annual precipitation of 2500 mm. The Brahmaputra River and the Barak River are two major rivers in the region with an annual runoff of 537.2 km³ and 59.8 km³, respectively. Prevalence of shifting cultivation over an area of 14 660 km² is responsible for an annual transfer of 88.3 × 10⁶ t soil and 10.65, 0.337 and 6.05 × 10³ t available N, P₂O₅ and K₂O, respectively. Soil and nutrient transfer depends on the amount and intensity of rainfall, slope, vegetation cover, soil texture and human interference. The major sinks for sediment and nutrients are the sea, responsible for an intake of 51.4% of the total transferred quantity, followed by river systems (14.4%), and seasonal streams (11.0%). A major sink for the forest litter and humus transferred from the hill slopes is valley land adjacent to the hills, which retain about 50–65% of them, making the soil highly fertile.

Key words implications; India; nutrient and soil transfer; rain water; sinks