of i 7.8cub.m. a second. The Chaktak-tsangpo had thus now 1 cub.m. less water than 12 days earlier at the confluence with the Tsangpo. One would perhaps have expected more water as the season was approaching the maximum of the activity in the Tibetan rivers. But, on the other hand, it should be remembered that on the way from Pasa-guk to the junction the river receives several tributaries, and further, that the summer of 1907 was very dry and the clear weather nearly constant, so that the melting of snow and ice did not show any acceleration in the beginning
of May.
A daily period of oscillations could be observed in the water-level. On June 8th, 12.30 P. M. I had a mark fastened near the bank au niveau with the water level; at 4.30 P. M. the same day the level had fallen 2 5mm. ; at 7 A. M. on the 9th it stood + 5 3 mm. ; 9 A. M. + 33, 10.30 A. M. + i 7 mm., I P. M. — 2 5mm., 4 P. M. — 45m. ; the river then continued to fall in the evening and perhaps a part of the night, and rose the next morning. The amplitude cannot be great as the river comes from a lake, Lapchung-tso, and is to a great extent fed by springs, but it shows the difference in the rate of melting during day and night in the upper reaches of some of its tributaries entering below Lapchung-tso.
Pasa-guk is a miserable little place of a few huts and tents and some poor inhabitants, but still it is a kind of emporium for salt from depressions and lakes on the northern plateau-land, and later in the summer a market is held here.
IIIFカラー高解像度
