Chemistry and isotopic composition of precipitation and surface waters in Khumbu valley (Nepal Himalaya): N dynamics of high elevation basins

The calculated atmospheric N load (0.30 kg ha− 1 y− 1) was considerably lower than the levels that were measured in other high-altitude environments. Nevertheless, the NO3− concentrations in the surface waters (from 2 to 17 μeq L− 1) were greater than expected based on the low N inputs from wet deposition.