Soil moisture is low throughout the basin for most of the year; this is because of low rainfall levels. Only in the western most reaches are soil moisture levels higher, owing to this area being the source of the river from snow melt of the Tibetan plateau.
- Global rainfall for 1985
- Global rainfall for 1986
- Global rainfall for 1987
- Global rainfall for 1988
- Global rainfall for 1989
- Global rainfall for 1990
- Global rainfall for 1991
- Global rainfall for 1992
- Global rainfall for 1993
- Global rainfall for 1994
- Global rainfall for 1995
- Global rainfall for 1996
- Global rainfall for 1997
- Global rainfall for 1998
- Global rainfall for 1999