Contrasting runoff trends between dry and wet parts of eastern Tibetan Plateau

Yuanyuan Wang,Francis H S Chiew,Tim R Mcvicar,Yongqiang Zhang,Guanghua Qin,Lu Zhang,Hongxia Li

doi:10.1038/s41598-017-15678-x

Abstract

As the “Asian Water Tower”, the Tibetan Plateau (TP) provides water resources for more than 1.4 billion people, but suffers from climatic and environmental changes, followed by the changes in water balance components. We used state-of-the-art satellite-based products to estimate spatial and temporal variations and trends in annual precipitation, evapotranspiration and total water storage change across eastern TP, which were then used to reconstruct an annual runoff variability series for 2003–2014. The basin-scale reconstructed streamflow variability matched well with gauge observations for five large rivers. Annual runoff increased strongly in dry part because of increases in precipitation, but decreased in wet part because of decreases in precipitation, aggravated by noticeable increases in evapotranspiration in the north of wet part. Although precipitation primarily governed temporal-spatial pattern of runoff, total water storage change contributed greatly to runoff variation in regions with wide-spread permanent snow/ice or permafrost. Our study indicates that the contrasting runoff trends between the dry and wet parts of eastern TP requires a change in water security strategy, and attention should be paid to the negative water resources impacts detected for southwestern part which has undergone vast glacier retreat and decreasing precipitation.

Highlights

This study focused on spatial representation of Q trends and its drivers over eastern TP solely using satellite-based products
Results indicated that P was the most important factor in determining Q trends and explained a major part of annual variation in Q
ΔTWS variations played an important role in regions undergoing distinct cryosphere dynamics, and ET trends were indispensable in determining Q trends in wet regions

Summary

Introduction

All the above data were obtained from satellite-based products. Precipitation data were sourced from the TRMM (3B43) precipitation product from Mirador at the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC)[25], which estimates 0.25o gridded precipitation by merging 3B-42 and gauged precipitation data. ET data from Jan 2002 to Sep 2014 were obtained from four state-of-the-art diagnostic ET products: PML26, GLEAM27, MOD1628, P-LSH29. The median of ET anomalies from the four ET products were used for the analyses. The anomaly, rather than the actual value, was used to overcome systematic bias in the different ET products (see Supplementary Information Table S3 and Fig. S1). Streamflow data for the five basins from Jan 2002 to Sep 2014, recorded by the Tibetan and Qinghai Hydrological Bureaus, we

Methods

Results

Conclusion