Tree-ring-based seven century long flow records of Satluj River, western Himalaya, India

摘要

River discharge provides the hydrological requirement of hydropower generation, irrigation and other day-to-day domestic needs of society. The recorded data spanning over the past few decades do not provide sufficient time window to understand the natural variations in river discharge in long-term perspective. A 711-year long composite ring width chronology of Pinus gerardiana (one site) and Ced-rus deodara (three sites) was developed from moisture stressed sites in Kinnaur, the western Himalaya. The precipitation responsive chronology was used to develop 711 years (AD 1295-2005) long previous year December to current year July Satluj discharge data using linear regression model which captured 37% variance in the observed discharge series (AD 1922-2004). The reconstruction revealed 50-year low and high river discharge in the eighteenth and nineteenth century, respectively. The decreasing tendency in river discharge noticed since the 1990s is consistent with the decreasing trend in winter precipitation in the region.