Estimation of glacier runoff and future trends in the Yangtze River source region, China

Abstract

Glacier runoff from the Yangtze River source region (YRSR), China, is estimated for the period 1961–2000 using a degree-day approach. In the investigation area, glacier runoff accounts for 11.0% of the total river runoff during the period 1961–2000. In the 1990s its contribution to river runoff rises to 17.0%. Due to the current rate of glacier decline, the impact of glacier runoff on river runoff has recently increased in the source region. Based on two different climate-change scenarios derived from ECHAM5/MPI-OM, future glacier runoff is assessed for the period 2001–50. In all climate-change scenarios, annual glacier runoff shows a significant increase due to intensified ice melting. There is an increase in glacier runoff during spring and early summer, yet a significant decrease in late summer. This study highlights the current and future impact of glacier runoff on river runoff in the YRSR.